Burned Turn Signal Fuse

cicero · May 27, 2009

I burned the fuse for my turn signals on my 04 Denali when I tried tapping the wires to a compressor for a train horn. Bad move, I know. So I'm looking through my fuse box and can't figure out which to replace. I took a bunch out and looked at them but none seemed burned. Can anyone help? And is it possible that it's not a burned fuse?

Thanks

txab · May 28, 2009

Are you looking at the correct fuse block? It's inside.

bill190 · May 28, 2009

So basically to confirm you blew the turn signal circuit/fuse... You tapped into a wire for the train horn, then something overloaded or whatever, then the turn signals stopped working. Correct? And everything else is still working OK?

The fuse on my 92 for this is called "Turn". Look for a fuse with a "Turn" label. Then replace the fuse even if it looks OK and see if the new fuse fixes the problem. It may be labeled under each fuse, or on a fuse cover, or in your owner's manual.

Of you don't have a fuse called "Turn", check each fuse with a continuity tester. A multimeter can do this when set to ohms. You place both leads together and get a reading on the meter. A good fuse would get a reading whereas a burned out fuse would get no reading (like you had the test leads in the air).

Also might check the wire you spliced into. Be sure it was not totally cut. Be sure that spot in the wire is still good.

Let us know what happens...

cicero · May 28, 2009

Yea, that's the right fuse box, but which one do i replace? There are four different ones that say turn, each for different sides or other things. But since I only tapped the wires on one of my headlights, wouldn't I only need to replace one, and the others should still work? Or are they somehow connected?

I'm going to try and replace the fuse labeled LT TRN, seeing as how I tapped the left headlight, tomorrow morning. Thanks again for the help.

bill190 · May 28, 2009

Please be specific as to the EXACT problem. ("Turn signals" not working is an entirely different problem from "turn signal" not working!)

Does the right turn signal work? Is it just the left turn signal which does not work?

When you turn on the left turn signal, does one light come on in the rear?

Do you have a multimeter? Can you test each fuse for "continuity"?

Do you know how to test a fuse to see if it is good or not?

cicero · May 29, 2009

Please be specific as to the EXACT problem. ("Turn signals" not working is an entirely different problem from "turn signal" not working!)

Does the right turn signal work? Is it just the left turn signal which does not work?

When you turn on the left turn signal, does one light come on in the rear?

Do you have a multimeter? Can you test each fuse for "continuity"?

Do you know how to test a fuse to see if it is good or not?

sorry, its actually the dayrunning lights that are not working. the turn signals still come on. i tried replacing the turn signal fuses but that did not work. so any idea as to what it is?

thanks again

brims · May 29, 2009

Please be specific as to the EXACT problem. ("Turn signals" not working is an entirely different problem from "turn signal" not working!)

Does the right turn signal work? Is it just the left turn signal which does not work?

When you turn on the left turn signal, does one light come on in the rear?

Do you have a multimeter? Can you test each fuse for "continuity"?

Do you know how to test a fuse to see if it is good or not?

sorry, its actually the dayrunning lights that are not working. the turn signals still come on. i tried replacing the turn signal fuses but that did not work. so any idea as to what it is?

thanks again

Should be a fuse for the DRLs, check that bad boy out. There may be multiple fuses, the 900s have 2 in series for some reason. Or say screw it, DRLs are useless in USA.

cicero · May 31, 2009

so how do i fix that? are these under the hood fuses or are they in the fuse box? sorry im not very truck savvy

TexasAl · May 31, 2009

Go to an auto parts store (or wally mart), and buy a multimeter. Use it to check the related fuses. You can buy a fuse tester, that will light up when you place the leads on the fuse leads. Good luck.

bill190 · May 31, 2009

so how do i fix that? are these under the hood fuses or are they in the fuse box? sorry im not very truck savvy

Ok, that is what we need to know. The exact problem as well as what you need help with.

If you need more detailed instructions, then that can be done. Just ask!

As to checking fuses, it sounds like your Day Time Running lights fuse has blown. You can find information about which fuse is located where in your owners manual sometimes. Or on the outside cover of the fuse box sometimes. Or on the inside cover of the fuse box sometimes. Or marked below each fuse.

Look for Daytime Running Lights or DRL.

Then a fuse is sort of like a light bulb. There is a little wire inside which can break and it no longer works. Just like a light bulb.

You can look at the fuse and see if the little wire has broken.

Or you can test with a "continuity tester" (multimeter) to see if it still is connecting the electricity from one prong on the fuse to the other prong on the fuse.

As mentioned above, I suggest you go to radio shack and buy a multimeter. Have the guy there show you how to use it to test a fuse.

Following is a simple web page which also shows you how to test a fuse with a multimeter, but ask for more instruction at Radio Shack too. The more you learn about how to do this, the better you will understand.

How to test a fuse...

http://www.dinosaurelectronics.com/Test_Fuse.htm

cicero · June 2, 2009

So I'm almost positive I've found the fuse to replace. It's not one of the smaller two-pronged fuses. It's one of the larger, cube-sized ones with four prongs. I'm going to try and get a replacement at an auto store tomorrow. Thanks again for all the help.

brims · June 2, 2009

That is a relay. 2 of the prongs are the coil, 2 are the contacts, they will probably be normally open. There should be markings on it somewhere, the prongs 85 and 86 are the coil they should have continuity; the others are probably 30 and 87, those 2 will show open.

Hope you read this before you spend a bunch of money on a relay. It should be ok, but it's possible it's bad.

TexasAl · June 2, 2009

That is a relay. 2 of the prongs are the coil, 2 are the contacts, they will probably be normally open. There should be markings on it somewhere, the prongs 85 and 86 are the coil they should have continuity; the others are probably 30 and 87, those 2 will show open.

Hope you read this before you spend a bunch of money on a relay. It should be ok, but it's possible it's bad.

I agree with brims. The relay is probably good. If you have checked all the fuses,and you did not find a problem, then perhaps you shorted out a fusible link, or perhaps a module, depending on what you did. You can probably swap that relay with another relay on your fuse box (make sure they have the same model number), and see if that works. If it doesn't, then the relay is probably good. I would check the fuses again, and make sure they are all working before looking elsewhere.

cicero · June 2, 2009

Good call. I switched the relay out with a similar one and that wasn't it. So I spent a significant amount of time checking the manual and finally figured out which fuse it could be. To my luck, it was burned, and I just replaced it with one of the spares provided by GMC. Thanks a bunch guys. You've saved me money and time.