Can a fuse appear to be good but in actual fact be blown?
I have seen several fuse that appear ok, and in fact are defective.
The best way to test, is with a computer safe test light, there not cheap but if you want to get serious about auto electric you need one.
To test fuses, you are generally safe with the cheap kind.
1) Plug in or clip on your test light. 2) Test your test light against a known good source for voltage. 3) Turn on the ignition switch. 4) Probe both sides of your fuse, the results should be the same. Note that one or two may be cold on both sides (or negative if you have a computer safe tester) They generally power the interior lights. 5) If you find a fuse that is cold on one side and hot on the other, you have found the monster. 6) Replace it with the same type and size.
IF all tests well and you have glass fuses, test the metal clip on both sides that it clips into. They may require cleaning, and careful bending from water/ rust damage. If you have plug in fuses, check the integrity of the fuse holder.
I have seen all types and sizes of fuse, especially glass, that appear good, but are blown.
Best way to check a fuse is take it out of the circuit and test its resistance. A good fuse will have very low resistance (less then 1 ohm). A bad fuse will measure "Overload" on your meter. You can get a cheap meter from and local hardware store for ten bucks. Even bring the fuse with you. The guy at the store will probably check it for free for you. Good luck.
A fuse is a deliberate weak link which will be blown if there is a power overload. When you blow a fuse, take the blown fuse out and throw it away as you would a blown light bulb, and replace it with another fuse of the same type. * In the old-timey fuse boxes a penny could be substituted for a fuse, but a penny is too strong to be blown, and the next overload…
If you are asking to see if it works, then get out the handbook and look under the fuse section. Then what you want to do is locate the fuse for the control panel and emergency check engine lights. In most cars the cigarette lighter and the panel are on the same fuse. Check the fuse to see if it is blown. A blown fuse will be dark in color or appear to look broken…
The interior lights back window lock and back window wiper all quick working at the same time in 2002 Jeep Grand Cherokee What would cause this?
Try looking at the fuse that corresponds to the things that are not working. Take the actual fuse out of the fuse box, and look at it, examine it. You will be able to tell immediately if the fuse is blown or not by the way it looks. If it is blown it will have some gray matter or black in there.....or the fuse will look messed up, or both. Good luck to ye!
How do you check for a blown fuse on your 2000 grand caravan you know where the fuse box is what do you do next?
Code P1491 means Rad fan control relay circuit. on a 2002 Ram check the fuse for the ac condenser. it is a 25 am fuse and it is located in row closest to rad and closest to engine. if fuse is blown it will look a milky colour.I know this for a fact as I just had to change mine as it had blown. The condenser fan motor is probably going bad and that is…
Half of my interior lighting radio and antennna don't work in my 1992 Jeep Cherokee. There is a rapid sound coming out of the fuse box area only when the car door is open. Is this a blown fuse?
My 1990 corvette power door locks quit working the fuses appear not to be blown is there a in line fuse?
I believe the question should be what is a BLOWN fuse and why should you never replace it with a penny? A blown fuse would be one that has been over stressed and has burnt out or blown out to protect the wiring or other part of the circuit. A penny would bypass the fuse which is the safety measure in the circuit. Bypassing a fuse could cause a fire or serious damage to the…