Alternators

Did you change out the belt? I had a chirping and squeaking on mine and my 95 Impala and I couldn't isolate it so I went with the cheapest repair, a new belt and low and behold it solved the problem. As soon as I hear a noise now, it's belt first then more expensive parts last! Good Luck

when I experienced this same situation, it was the ground wire from the engine to the body of the car. You should have a ground wire going from the engine block or intake manifold, etc., to the firewall of the car. To test this out, use a piece of wire with alligator clips on either end and and "short" the block/intake manifold to the firewall.

Take a look at the voltage regulator. if it is externally regulated it is most likely up near the headlights mounted to the body, if it is internally regulated its inside the alternator housing. Easy way to tell is if there is 3-4 wires on a pigtail going in to alternator, its internal, if there is only 1-2 wires going to the alternator its external. External regulators cost around 10-15$, internals are around 25$. still cheaper than a new alternator. For peace of mind, just take it off and bring it to the guys at the part's house so they can bench test it off the vehicle.

Bad diodes in the alternator can cause the battery to go dead when the car is off. The diode bridge (six diodes) is directly connected to the battery, and is used to convert three phase delta AC from the alternator's stator to DC for the battery. Normally, if the engine is not running, the diodes are reverse biased and do not conduct current. If one of the high side diodes is shorted then the diode trio (another set of three diodes supplying the regulator/rotor) could conduct and drain the battery. Often, a diode failure is a short or an open. A short in a high side diode along with a short in a low side diode would result in high current from the battery, and that would probably blow the fusible link. An open would result in poor performance of the alternator.

If it is a drive belt and not a serpentine belt is has no tensioner. You manually adjust the tension by normally adjusting tension by moving the alternator. Loosen to bolts holding the alternator in place and then adjust the tension. Tighten the bolts when the tension is right. If it is serpentine belt if you follow the belt around the the engine you will see the tensioner.

If you are careful and do not let the positive cable to the alternator come in contact with the motor or frame, nothing will happen. It is just a lot easier and safer to disconnect the positive cable from the battery. It saves possibly shorting out the cable and possible ruining the battery.

Voltage Regulator

The engine computer is the voltage regulator.

It could be any number of things, from a faulty diode inside the alternator (the alternator could be working reasonably well but still have a bad diode) to a sticking relay.

Sometimes those types of problems can be difficult to find, especially since they are often intermittent.

Remove the lower Radiator Hose, Radiator shroud, then release the belt tension, slip off the alternator. up top just move the air intake hose , may need to unplug the mass air sensor and/or the air temp. sensor . three bolts hold the bracket to the alternator the just unhook the unplug, and the power wire make sure the BATTERY IS DISCONNECTED! Installation is just the oppisite. about an a two hour job give or take few!

that alt belt is a serpentine belt so you should take a picture of how the belt looks right now and then put a wrench on the tensioner pulley and relax the tensioner so that you can pull the belt off of one pulley then you can let the tensioner back so you have both hands free to pull out the old belt reverse steps to replace

I thought mine kept dying. Ended up being a bad fuel injector. Draining power somehow... bah.

Your belt is correctly tensioned?

old myth, bad for alternator, dont do this..

The serpentine belt configuration for a 2004 6.0 diesel engine typically runs around all the engine accessories and over the idler pulley. A single belt is used to power the alternator, power steering pump, water pump, and AC compressor.

I doubt it but you need a manual on your car from AUTOBOOKSONLINE.COM and it will have pictures and everything From what I have read elsewhere, the sephia, like the hondas that used to drive me nuts, require the removal of the lower wheel axle/control arm to remove the alternator. Not sure what year model this applies to and if it has been resolved in the newer designed spectra/sephia. that is completely wrong you can take that fuel line off that runs above the alternator or you can bring it way over near the air box to get it out or just pull the wheel off and the slash guard

must removed the shield that covers the the fan in front. once that's removed you could get a better clear area to get to the alternator.

Check the battery cables for corrosion. That can often be a problem. Also check the fusable link that often goes from either the battery terminal to the inside of the car or from the starter HOT lead to the inside of the car. It depends on the type of car.

There might be a short somewhere, and it is drawing alot of power. It is like an electric chair...When extra voltage is used, the lights flicker, and when the switch is off,it goes back to normal. trying to find the short could be hard though.

Wrong alternator or new alternator is bad. no resetting needed

Disconnect the battery. Put it on the charger (optional)

Remove the wipers, after marking how the arms line up to the posts (or not, whatever).

Remove the plastic cowl (requires torx or allen wrench for the 6 screws, there are 2 quarter turn plastic pieces that you can break off if you want, and 4 little nut looking things under the hood). This is the second hardest to separate from the vehicle.

Remove the wiper assembly, 4 nuts on top, 6 bolts into the firewall. Be careful to remove the brittle drain tubes from underneath either side. Also, disconnect the wiper wiring connector. Lift at a slight angle.

Remove the belt (the tensioner is in front and below the alternator. Put a 15 millimeter box-end wrench on there and push clockwise to relieve tension).

Loosen the bolts that hold the alternator bracket on top, including the top alternator bolt and the bolt into the intake plenum. Now remove the bolts and bracket.

Push the alternator back and carefully disconnect the plug. Un-bolt (10 millimeter) the cable from the B+ terminal. If you can't quite get it off, proceed to the next step, but don't pull too hard.

Remove the lower (pivot) bolt. This will require holding the nut on the inside with a box-end wrench while using a ratchet on the bolt head. Remove the alternator from the mount gently wiggling and pulling. I found cursing helps a little. If you didn't before, disconnect the electrical connections.

Getting the old alternator out is a bit like a bar puzzle (you know the kind with 2 twisted up nails?). Turn it around to fit how ever it makes sense, the new one goes in the same way, so pay attention.

Installation is the reverse of removal (by definition).

Be sure to tighten the pivot (lower) bolt to respectably tight (there's a little sleeve that will mash up to the mount); it acts as a ground and if not a sure connection the alternator will not charge. You don't want to have to do this again, right?

belt needs to be tighter and remove all oil and grease with cleaner and possibly use some belt dressing

Install a test light in series with battery. If there is a current flow light will illuminate. Remove 1 fuse at a time until light goes out that will determine which circuit is drawing current. Then you can trouble shoot that circuit. May be concealed light i.e. glove box is left on. Could also be voltage regulator circuit is not opening when vehicle is shut down.

When you've got an Isuzu Trooper Alternator going bad, you've got all kinds of problems. If your battery isn't charging completely and quickly, you can get stranded, and if your interior electronics aren't getting the power they need, they're not functioning the way they should. You need to replace your Isuzu Trooper Alternator right away, and you want to make sure you get a quality replacement, because you don't want to have to do this again any time soon.

I didn't see value in the above answer so here is mine:

Pretty much like all alternators:

1:Disconnect negative battery cable.

2:Loosen adjuster lock, remove tension on belt, remove belt from alternator.

3:remove adjuster bolt (the one that goes into the alternator).

4:remove electrical connections - one is fastened with a small nut -> goes to battery. The other is a simple plug. There are two kinds of plugs. Make sure the replacement is the same kind of plug (depends on amperage).

5:remove long pivot bolt.

6:Remove alternator through the passenger-side wheel well.

Installation is reverse

Takes about 1-2 hours.

1st, disconnect the battery. Then remove the 2 bolts that hold it in place. The one on the top of the alternator is accessable from the top and fairly easy to get to. The bottom one is a little tricker.. You have to remove the front wheel. Then there is a plastic access panel that needs removed. After removing that you have access to remove the bottom bolt. Then remove the wires.. there you have it ! 1st, disconnect the battery. Then remove the 2 bolts that hold it in place. The one on the top of the alternator is accessable from the top and fairly easy to get to. The bottom one is a little tricker.. You have to remove the front wheel. Then there is a plastic access panel that needs removed. After removing that you have access to remove the bottom bolt. Then remove the wires.. there you have it !