How to test an ignition coil

This testing procedure is valid for just about any automotive coil. Using an ohmmeter, check the resistance between the side terminals of the coil. Do this with all of the wires to the coil disconnected.

You should see 0.75 to 0.81 ohm of resistance. Then check the resistance between either side terminal and the center high tension terminal. The reading should be 10,000 to 11,000 ohms. Any significant deviation from these numbers would indicate that the coil could be defective.

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You can also rest an ignition coil by using a volt meter.There should be a little over 12 volts pulse, or a dip and peak in the meter needle, rather than a steady 12 volts, at the output, while cranking the engine.

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Be careful about these answers. My voltmeter has a 9 volt battery installed. An ignition coil can produce 20 kV - that is twenty thousand volts! - at 100 mW, now that would bother me a bit.

So now, how can we check this coil safely? Well, start by shorting the output (the high tension terminal) and check the primary winding for continuity. On a normal meter 0.75 ohms might be very hard to read but, if you use a 1.5 flashlight bulb and battery in series with it, if the bulb lights, the primary winding is probably ok. (Unless its insulation has got fried by a fault called a "shorted turn", in which case the flashlight bulb will still light up but the ignition coil still won't work...)

The secondary, high tension, winding of the coil can be checked by shorting it with a high resistance load having a tap to form a 1000:1 split ratio, so you can use your meter to check for an output voltage of around 20 volts when a small 1.25 volt battery is connected and disconnected to the primary.

The actual output voltage should let you work out the turns ratio between primary and secondary of the coil. maybe Note: to see the output voltage for a longer time, add a diode and capacitor onto voltage divider tap.
I need to know how to check a coil on a Honda accord 94

There are 2 fuse boxes / fuse panels in nearly every Ford product: one directly above the driver's left foot (when the driver is actually sitting in the driver's seat). The other is inside the engine compartment, on the right side - contains high current fuses.

There is extensive coverage of fuses and the circuits each one protects Owners Manual.

See "Related Questions" below for sources of free online Owners Manuals for 1996+ Ford & Mercury products.

Inside the fusebox cover is a small white plastic tool for pulling fuses out.

Inspect the center section of the fuse to determine if it has 'blown' - it will be obvious if the metal strip has melted.

Insert a replacement fuse of the same color / amperage protection by simply pressing it into the fuse-slot.

Generally, if a fuse is 'blown' you can tell by looking at the fuse. Look at the wire looking thing in the top on the fuse. It'll look kind of broken or burned or just otherwise messed up. If you're not sure what a good fuse looks like, go to an auto store and look at a new fuse. Then look at your fuses and compare appearances.

There are actually two separate covers. One is for the circuit breakers and one for the fuses. There's a tab in the center that you squeeze together and it pops off. In the cover you'll find spare fuses and a puller. If you still need to get the breaker cover off, there's a tab on the corner marked "lift". With the other cover removed, you can then unsnap the tab and wiggle it out.

Go to the dealer service dept and ask them to photocopy the diagram out of their service manual for you. They should do this for you with no problem.

If you want an owners manual try MOTORLIT.COM.

Under the dash just to the left of the steering column.

Underneath the drivers side kick-board / panel underneath the steering column.

One fuse box is located under the hood by the battery. Another is under the left side of the dash. Carl

Not real sure for this model but I think there is a fuse box by the battery under the hood and another one under the left side of the dash. Carl

power fuses are next to battery in a black looking contaner there is a lid that has to be removed. the regular fuses are located underneaath the dashboard on the drivers side above your left foot... if you are sitting in the van

there are two fuse boxes, one is in the engine compartmente near de battery, the other one is under de driver side near the steering column.

It depends on the fuse. Most of the fuses in use today are small plug-in plastic devices. Simply grab them with needle nose pliers or a fusepuller and pull them straight out. They are color coded as to ampacity. There are two fuse blocks in the Windstar. One is in the engine room by the battery. The other is under the left side of the dash. Enjoy.... Carl

you can go to www.alldatadiy.com and you can buy a subscription for a year just for 25 bucks plus they have a lot information about your car, works pretty good for me.

I think I seen it on this sight http://autorepair.about.com/cs/generalinfo/l/bl_img_ford023.htm

you have to look around. there are a lot of pages.

Click on the "Ford Website" link below

Click on Owner Guides

The owners manual ( which includes the fuse panel diagram ) can be viewed on-line

Here is some advice from contributors:

• Sometimes your car will just plain stop running if you have a faulty coil wire. I had this problem before where it didn't matter what time of day or the weather, it turned out to be a coil wire.

• I have an automatic '94 Nissan Sentra that would stop at the strangest of times (while it was being driven) at least once or twice a week. It would drive me crazy. I would take a turn at a light, and right in the middle of the turn, the *car's power would go out and stop. The only thing that would work was the brakes (thank God!). And then I had to quickly start it up again and pray that it would get me home. This was especially embarrassing when I had a date in the car. Does this sound familiar? Well, I found out it was an electrical problem, as well as a fuel pump that needed to be replaced. Cost me a good $300 to fix. That was about 2 years ago so I'm sure prices haven't changed much.

• My car used to just stop in the middle of the road, and then could restart no problems. It turned out to be that the alarm was old & faulty & the alarm was connected to an immobilizer which was a bit over-zealous - hence immobilizing in the middle of the road. The solution was simply to remove the alarm (the whole thing had to be removed though, it wasn't good enough just to turn it off).

• Because the gasket plate (insulator) is worn out, this happened to my 1984 Honda Accord. .

• I have a 96 dodge caravan and it would do some of the same things. Sometimes it would not start in the morning wait a few min. and then it would start, sometimes it would just cut out while driving. The solution after all the relays were changed was a new computer. It was covered under a Chrysler 8 year warranty. lucky me as it saved me $1000.

• I had my 92 Oldsmobile fixed it turned out to be torque converter needed to be replaced now the car works.

• if your alternator goes, no more power the engine will stop...

• This is a problem with a lot of vehicles that is overlooked for this reason: when a mechanic will hook up their computer and download the codes from the car's computer, the codes will generally tell you the problem the car or truck is having, if the car or truck kicked a code to the computer. Then the car or truck will run through a diagnostic system check and when the system check comes back fine and there are no problems then what?
• Sometimes the problem can not be found by the computer and the reason is that when the car or truck runs it's system check, everything checks out fine! How can this be when the vehicle just stops running and then starts running after you pull to the side of the road and shut it down for a couple of minutes?The answer is simple.The ignition relay acts like a breaker in a house; when you have a relay that is weak, you will get this problem. But the computer will test it as good because it still is good.It's just weak, making it trip.The reason it will start again is because the relay will automatically reset itself after the relay cools and you are off and running again.To explain the type of reaction your car or truck would experience if this were to happen is as follows:The car or truck will just plain die! no warning!IT WILL NOT spit and sputter like it is running out of gas. Now, a module for the distributor will act the same way, but the difference is that the car or truck will not continue to start after a period of time.My suggestion is a cheap way to fiqure this out: purchase a continuity tester at any local hardware store (they are only a couple of dollars) and check the leads coming from the distributer mod. If it is good, it will light up the continuity tester. If it is bad, it won't. This only works if the car will not run at all because the mod will check good if it is weak as well as the ignition relay.Another way to fiqure this out is to go to a local junk yard and pick up a distributer mod and a ignition relay and it will cost you maybe the better part of $10.00 and you may be worry free as long as you own the car with the used part.But if you feel uncomfortable putting used parts into the ingnition system, then replace one or the other but not both and see which one works and then buy new.

• Check your computer for trouble codes.Any problem will be stored in the computer,even if it is intermittent.

• Usually it is some type of fuel pick up problem, or fuel filter. It is possible the engine was slightly flooded, causing it to loose power. This all happened to me when i had an 1987 Corvette. One day i was driving, then it just stalled when i was on a local road. Thank god not on a freeway, cause when it stalled, the steering became locked up. But i did what the manual told me to do, if the engine has became flooded, push the accelerator to the floor and crank the engine. And that go me going again, and strait to the mechanics. It was all in fuel pick up and i need a new fuel filter.

• Just replace the distributor cap and roter. I had same problem in my Honda accord 98.

• My car stopped all of the sudden while driving. When I tried to start it, it started but within seconds the engine would turn off. So my car had to be towed. The problem happened to be the ignition switch which eventually had to be replaced with a new one. It cost me about $600.

• I had a 1990 Honda civic that would not start when the ambient temperature got high. I diagnose it and found that the base of the fuel pump relay situated just behind the dash had a poor solder connection.I re-soldered the connection and it was the end of my problem. Just thought you could possibly have the same problem.

• Most common problem I have found is the idle control value (aka. idle stepper motor). It sets the idle for the engine control computer. It bypasses the throttle plate. They get gummed up, I believe from PCV fumes.This has caused intermittent low idle/dying and start-up problems. The gum prevents it from responding fast enough. My Porsche had low cold idle. My Tahoe required tap on accelerator to start (usually flick of key). My Range Rover intermittent dying & inconsistent low idle. All idle control valve. FIX: Remove it and clean the spring/plunger with Carb cleaner. Also take cotton swab and clean seating area with cleaner. Sometimes replacement is necessary, mine have ranged from about $45 to $125 depending on vehicle and source.

• I had a Vauxhall Carlton 2.0i which would stop for no apparent reason. It was driving me mad. Just couldn't find the cause. In desperation, took it to the main dealer. He put in new plug leads, new distributor cap, new plugs, and 'tuned' it. It did exactly the same the next day. Back to the garage.In the end I found it myself. Locate your Fuel Injector Relay in your fuse and relay box. When your car stops, pull this relay out, and tap it sharply. Re-insert it, and if the car starts again, that's your problem. Apparently the inside circuit board breaks down, and a new relay is the only answer. Intermittent faults like this are a total pain. In fairness the dealer gave me a full refund for the work that they had done. someone else.

For more information please refer to the related link.

It is necessary on cold, especial extremely cold days. REASON BEING: Is that it takes the oil to reach it's proper viscosity longer time than on warm days. When you do start car, don't race it or you'll be doing more damage. Let it stay at idle for about 3 - 5 minuets until you see the temperature gauge start to get to move to a hotter position, or better yet, until you have heat. Reason is that thick oil cannot easily flow though tiny holes in crankshaft, push rods not getting oil into small spacers in cylinder block, valve guides, rocker arms and oil control rings leaving a dry cylinder wall, which causing wear to cylinder bore. Sometimes in really cold places, they suggest using a lighter gauge oil.

I will give my answer which is in opposition the the above answer somewhat. In years past when cars had carburetors it was a necessity to warm the engine up before driving off because the engine simply would not run correctly until the carb got warm. Today it is a bad idea to let the car idle for more than a couple of minutes max before driving off. Reason being is that on todays modern engines with computer controlled fuel management systems it is not necessary and is in fact a waste of fuel and pollutes the atmosphere plus harms the converter. Modern fuel injection systems do not need to warm up to work properly as an old carburetor did. They work instantly and the ECU adjusts the fuel/air mixture to compensate. Modern oils of today are also a far cry from what they were decades ago. Modern Oil sticks to all parts better today than in the past. This is not the same formulation that we had decades ago. There is a thin layer of oil on all parts when you start the engine due to modern refinery processes, so you are not causing wear to that engine if you drive slowly until it reaches full operating temperatures. Modern vehicles will warm up very quickly if driven but not so fast if sitting at idle. You are also doing your catalytic converter no good by letting this very rich mixture of fuel/air enter a cold converter that does not work well when cold. Just drive away slowly, avoiding full throttle until the engine is warmed up. This is 2010 not 1955. Things have changed.I can see the above point of view. But there is still a disagreement on oil. yes there will be a very, very thin layer of oil on the cylinder walls, but even sythetic oil will settle downwards ,and on a 20 degree day will be sticky and wipe off in one piston stroke. it still ,in my opinion, takes a little bit of time for oil to thin out as it gets warm. Has enyone ever went to change oil on a 10 to 20 degree day. It barley comes out of the drain hole, unless you let it run for even a minute, can you picture this oil flowing through tiny openings. however, point is well made that idleing and driven slow for the same amount of time will do the same exact thing. Main point is ; don't reve the engine right away, or drive fast for a few miniutes. Note: in places like Alaska, they use a heating source overnight because the car may not even turn over or do it slowly, because the oil is so thick.

Ans 3 -The second answer is the correct one. Letting a modern engine idle for long periods is not good with modern oils being as 'clingy' as they are.

Here are more opinions and answers from other FAQ Farmers:

• If I remember right I think compression is the 3rd element to an engine running. timing belt or timing chain? You need to eliminate each one(fuel,spark or compression)first and then continue narrowing down from there. I have seen dampness cause ignition wires to fail among a multitude of others. Have a real tech troubleshoot it, other wise your gonna replace good parts guessing.

• It is one of three things. It isn't getting proper spark, proper fuel, or proper compression. Use the process of deduction and find out. If the engine turns over the starter isn't bad.

• Well it depends on the car but it could be that you don't have spark, you could have a big vacuum leak, timing might be off. But don't flood your motor if your in a hurry!

• There are several possibilities: lack of fuel, sprk or compression, these are possible Maintenence items among many other possiblities: spark plugs (worn), ignition wire (Worn), distributor cap (worn), distributor rotor (worn), fuel filter (too dirty), air filter (no air getting in) and timing belt (timing is off).

• It is worthwile to check for spark from the coil before considering the distributor, spark plug wires or sparkplugs. Assuming that lack of spark is the problem.

• Another thing it could be is that your car is flooded , requiring possibly 3 hours for plugs to dry.

• I had a problem on a 1994 ranger that turned out to be a motion switch that had been tripped when the car was bumped. It caused the electric fuel pump not to turn on.

• If the car is a Chrysler product and just cranks but won't fire, it could be the fusible link. On Ford and GM cars the car will not even crank if it is bad but on Chryslers it will just crank. I don't know about imports.

• Other possible sources of fuel related problems are a collapsed fuel line(depending on how old the car is) or plugged filter. Before you drive yourself nuts trying to locate the fuel shut off that the fellow described on the ranger.....it's been my experience that is only on ford models(you don't say anything about your make or yr)in the trunk in cars. Good luck

• Correction: It's primarily fuel, spark, and timing. Timing problem of course can lead to lack of compression. Clarification: The comment on the '94 Ranger is correct. Many Fords have what is called an "inertia switch" which will cut off the fuel pump. This is designed to benefit the occupants in the case of a severe accident. I don't believe any other domestic maker uses this, but some imports do such as Jaguar.

• A GASOLINE internal combustion engine needs 3 things to function properly: 1) fuel, preferrably delivered at the right mixture, but generally if it's there and the other two components are met, the engine will at least run. 2) ignition, often referred to as a spark or fire, ignition timing must be within a couple degrees of factory settings otherwise the engine may not run at all. Ignition spark strength must also be high enough to be adequate for the air/fuel mixture to ignite, but generally it is an all or nothing situation in the newer, electronic ignition systems. 3) compression, if the compression is up, the cylinders, valves and camshaft are functioning adequately and the timing chain/belt/gear is timed properly. If all three of the above conditions are met, the engine will start when it is cranked. To find out why it won't start, you have to find out which of the above conditions isn't being met. Rather than approach the problem in a "shotgun" manner, it's best to be methodical in your approach. First, spray some starting fluid into the air intake while a friend tries to start the engine. If the engine runs briefly while you are spraying starting fluid, you have good reason to believe that the engine is not getting fuel... item 1 on the requirements. If the starting fluid didn't give you any clues, pull a sparkplug wire from the plug (any one will do) and connect it to a spare sparkplug. Set the sparkplug on a solid metal part of the engine and have your friend crank the engine again while you watch the sparkplug. You should see a bright spark if the ignition is working properly. And finally, if the above two tests didn't give you any information, run a compression test. Since all valves and all cylinders don't generally fail at the same time, you'll only be testing the timing of the camshaft, but that's pretty important. Mark the location of each sparkplug wire. I generally use a piece of masking tape with the cylinder number, then wrap the tape around the sparkplug wire, making a little flag or tab. This part is important, since you don't want to finish the job and wonder where the wires go. Next, pull the sparkplugs and carefully observe the condition of each plug. Look for oil fouling, wet plugs, WHITE plug insulators, worn plugs and damaged plugs. If the center insulator (the part that goes INSIDE the cylinder) is too white, it's an indication that the engine is running too lean and you could be causing damage to valves or pistons. If the plug is black and oily, it indicates that the cylinder is worn and oil is leaking past the rings or valve stem seals. If the sparkplug is wet with fuel, it's an indicator that the cylinder is FLOODED, meaning that somehow there is too much fuel being delivered, and a wet sparkplug cannot properly ignite the fuel in the cylinder. If the plugs all check out ok, use a compression gauge while your friend again tries to start the engine. Since there are no plugs in the cylinders, the engine won't start, but you're measuring the pressure that is built up in the cylinders. Generally, it should be around 90 PSI, but that number may be different for different engines. Generally, the number should be withing 5 to 10 PSI for each cylinder. A variance of more than 15 PSI indicates burned valves or worn rings. If ALL cylinders are low, (below 70 PSI) it's a good indication that the camshaft is no longer timed properly. That is caused by a slipped timing belt or timing chain.

• THE 'KEY' COULD BE THE ANSWER. Well... some recent cars/vans have a immobilizer embedded. Such a car/van can only be started with an original key i.e. a key which comes with the cars and which has a electronic chip. So if you have recently cut a key from any roadside key-cutter and your car turns using this key but the engine fails to fire it could be the immobilising safety device in your car that's preventing it from starting. This is a good safety feature!

Another ting to try is removing the spark plugs (make sure you re- cord which wires go where) and pro vidind that the engine isn't flooded

spray some starting fluid(avalible at auto parts stores) in the hol where the spark plug was and put the spark plugs back in and try to start it if it begins to start but then shuts off

your problem is proboly fuel delivery, but if the engine is flooded take out the plugs and let it sitt for a while to dry out.

There is a little sprocket in your strarter looks like a cog with teeth on in, but the teeth can chip or break if the metal is cheap which in most cars now days it is. So the starter is turning but the missing teeth are not connecting to make a spark keep turning it samething happened to my Buick but i didnt gte is fixed rite away because if you keep cranking evetually the teeth will catch and ignite

a motor needs fuel/ spark / air / compression all at the correct time check sources of all from major parts to minor (id start with anything electrical) you should find the problem

- One other thing that could possibly have gone bad is the main relay, its a $50 part that gives the fuel pump power when the key is on, so bad relay, no power to pump, no gas, no start.

-you need, spark, compression and a proper fuel mixture for your car to start. Generally, the compression gives way over time, so it is the last thing you should suspect if this problem appeared overnight. First thing you should try is to turn the key to the "on" position (not the crank start position). You should hear an electronic hum coming from the fuel tank. If you don't hear the hum, check the fuel pump relay or fuse. If those are fine, the fuel pump is suspect. If you do hear the hum, your fuel pump is working fine. Check for fuel pressure in the fuel line. It should look like a valve like the one you might find on a bicycle tire. If fuel sprays out, your fuel pressure is fine, which means you can suspect the spark. The battery is not the culprit (it turned the starter remember). Check for spark as noted above. If you don't get spark, check spark from the coil. Depending on the model and technology of your car, you can then suspect the ignition control module (esp. if it was a hot day) , as well as the distributor and all its components like the rotor and distributor cap.

By the way, most, if not all new cars have an inertia trip switch. Mine is under the dash. .

• The bigger question is why do you need to add fluid? After you locate and fix that leak, you can address the whine. If it is a Ford, it may be somewhat normal. Like Drazi said, "It may be air trapped in the line." Or the pump may be damaged from running it dry, or there is bilge in the line, starving the pump. Let's assume you have kept up on the maintenance and have flushed the fluid when it was dirty. Let's also assume that the pump is not damaged and you have found and fixed any leaks. Try this: pull the fluid out of the reservior and add one bottle of Lucas brand power steering additive, and top with power steering fluid. I have found this stuff pretty good at resolving many power steering problems. I'm not a big supporter of "Snake Oil", but have had good luck with it.

• If it's a Ford, it's because they use plastic parts in their casings, though most other car companies do the same. If that's not the case, then your pump is receiving too much stress from turning. Try lubing up the chassis and changing the fluid completely. It wouldn't hurt to check your lines either. Sometimes blockage can cause too much stress on the pump too.

• First thing is why are you adding fluid. If it has a leak, then I would address that problem first. A pump will not bleed air out of the system if it is leaking. If everything seems to be okay and your pump still whines, then replace the pump, preferably with a new one from the dealer. The so-called rebuilt pumps that you can buy from places like Autozone, O'Reilly, etc. are cheaply rebuilt, especially if it's a Ford. They don't bleed out air properly, resulting in improper pump pressures. A good pump will bleed out almost immediately, with the turn of the wheel a few times. If it doesn't, then your pump will more than likely never completely bleed out. Buy a new pump from the dealer--it costs more, but if you're like me and don't like the noise, then it's worth it.

• You probably have air trapped in the power steering fluid system. Bleed the air out by revving the engine to about 1500-2000 rpms and turning the steering wheel almost all the way from one side to the other a few times. This should bleed out the air and take care of your problem.

• If the noise is similar to that of a dry bearing, then the problem is probably the power steering pump itself. If the noise you hear has a "click, click, click" to it when you make turns in your vehicle, then the problem is more-than-likely your CV joints. If the noise is screeching, check your belt for wear-and-tear and proper tension (see owner's manual), and the pulleys that the belt turns, including the air conditioning compressor motor and its clutch/pulley.

I just wanted to add another two cents about the topic of bleeding or burping the power steering system:

1. Know what type of power steering fluid is needed for your car. Some power steering pumps can use automatic transmission fluid, others have specific power steering fluid for each car, i.e. Honda requires and suggests that you use Honda's brand of power steering fluid (see owner's manual). Make sure you know, or the warranty from the dealership or from the parts store may be voided.

2. Before attaching the power steering belt, fill pump with required amount and type of fluid (see owner's manual), and then turn the pulley wheel by hand a few times. This helps cut down on dry turns before they can happen. If more power steering fluid is needed, fill accordingly.

3. Attach the power steering belt with proper amount of tension (see owner's manual).

4. Turn vehicle on and proceed to turn the steering wheel all the way right and left 3-4 times.

5. Turn the vehicle off, and examine that the belt tension is acceptable, and again check the level of fluid and fill accordingly.

6. Always, always check your owner's manual before performing any maintenance on your vehicle. An educated car owner is a safe car owner!

www.powerbrakeandsteering.co.za

I too experienced very loud whining noise from my 93 Ranger 3.0's power steering pump at idle, and even louder when turning the steering wheel even a little bit in either direction. I changed the fluid but there was no change in noise. I read in a Ranger forum that if you add some STP oil treatment (yes, STP OIL TREATMENT), not the whole can, it would help. I decided to give it a try and sure enough it has reduced the noise greatly. It didn't completely eliminate it but people no longer stare at my vehicle at red lights because of the noisy pump. That was embarrassing! Ford's pump must be partly to blame since the problem is so rampant among all their various models.

By the way, Mercury is supposed to begin being phased out (discontinued) beginning in 2010 and completely gone by 2012. Only Ford and Lincoln will remain. Just thought ya'll might want to know that since your Mercury's value will likely plummet as that kill-off nears. However, those of you who have a stiffy for Mercs may get a good deal on one before they are gone. I personally don't think they are "all that". Fords in general are pretty low market in build and longevity. I used to favor GM but switched to Honda products in the 90s, they are very long-lived. My latest is a Jaguar and I'm quite happy with it. Yes I know they were owned by Ford and now by Tata Motors but the design is all Jag.