Turn signal fuse blowing

stebob · August 10, 2006

Ok, I have a turn signal fuse blowing issue that I can NOT track down. Here's what's happenin:

1997 Z71, auto trans

The turn signal fuse blows (fuse 16) intermittantly when I use the right turn signal. It doesn't always happen and I can not get it to happen sitting still, it seems as though I must be moving. I put a buzzing circuit breaker on the fuse in the fuse box. I have also removed the upper and lower trim covers for the steering column. I have gone through the wiring from the multi-swithc all the way out to the tail lights.

I can not find a problem in the wiring.

I have disconnect the tail lights to rule out the pcbs, same issue.

I have replaced the electronic flasher, issue persists.

I have disconnected the trailer harness and same problem. Although, I did find corrosion in my trailer harness and was sure that was my problem. Nope..no such luck.

I have had the right turn signal on and gone through the wiring from the column all the way out and can not get it to buzz. I've prob. tried hitting the turn signal stalk 1000 times sitting in the driveway and NOTHING. WOrks fine. I can, however, get it to happen within 2 miles of driving.

Now, I've discovered that when the issue happens it doesn't matter if I hit the left or right turn signal the short happens. But, it's only triggered by going right. I have been able to get it to keep happening twice at this point when I slow down to a stop. It usually stops happening when I start slowing down. What I found when I was able to stop when I hit reverse the buzz in the breaker gets more intense. Now, if I turn off the turn signal, the buzzing stops and not in reverse. BUT, if I go to reverse, the buzz comes back.

The back up circuit is also on fuse 16. So that sent me looking at the nuetral safty switch on the side of the tranny. Could find ne problem there nor could I get it to happen by messing with the wires. The buzz stays there as long as I'm in reverse IF the turn signals are also acting up. BUT, if I take it out of reverse, and have the signals off, no buzz. If the signals are working normally, then I go to reverse and no problems there either.

I hope this was clear enough to follow. I'm extremely frustrated and not sure what to do next. I thought I had it narrowed down to the TWO HUNDRED dollar multi-switch in the column until I came across this reverse issue. To sum up, it only happens when I'm driving and hit the right turn signal. Then left or right set off the buzz. It also buzzes when I go into reverse, but goes away when I exit reversea nd the turn signal is off. I'm at a complete loss.

HELP!! PLEASE!! I'm going NUTS!

ChevyTech007 · August 10, 2006

Intermittent shorts are the worst! I could be the switch but the next thing I would do is to install an in-line 10 amp fuse just down stream of the switch on the green wire. Drive to get the fuse 16 to blow. If the in-line fuse blows, you know the short is down stream of the in-line fuse and the switch is OK. Then you can move down the circuit using process of elimination. This technique has worked very well for me in finding shorts like yours.

stebob · August 10, 2006

Thanks! That's a good idea. Boy, where would I tap into that wire at? I can't get to it. I would imagine I would have to get into it after the big connection block under the dash. I'm not sure if I can get to it in the steering column harness or not. I'll check.

And, you're right, this kind of short is the WORST! Thanks for the idea!