Popping turn signal fuses 94 silverado

[Erik the Awful]

Check your wiring diagram and see what wires run from that fuse. Chase only those wires. Ignore the people saying "One time, at band camp, my truck had a taillight problem."

 

[Moparmat2000]

Well I got brakelights finally. Took brakelight switch apart and contact was burnt. I cleaned up and polished out the pitting in the contacts with 3600 sandpaper and reassembled the switch for troubleshooting purposes. Works great. Found a rubbed bare wire and repaired that. Still have a dead short in the turn signal circuit. But I have running lamps, brake lamps and hazards. So its halfway fixed. I'm thinking this tells me the dead short to ground probably is not in the exterior wiring but unfortunately for me is somewhere inside the dash.

I also lost the spring clip to the brakelight switch that mounts it on the pedal. I as I took it off it went sproiiing and it's gone somewhere in the dash since it certainly didnt end up on the floor. Kinda pissed me off. I searched for it for almost an hour. Will hit my buddies wrecking yard to get another clip. I guess I will be pulling the fuse box and unwrapping wiring next.

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[Moparmat2000]

Well I think I got this narrowed down pretty good. Output side of the fuse block has 2 dk blue wires. These both go about 2.5 foot from the turn/backup lamp fuse right to the positive side of the flasher relay in the convienence center just on the inside of the firewall behind the bulkhead plug. With the 3 fuses removed from the 3 circuits on this bus so I can do an ohm check, I get continuity 0.000 from the fuse to the plus side of the flasher relay plug as expected. I also get continuity 0.000 from the same blue wires when I jump the probe to a body ground.

When I do the same with the ground side of the flasher plug, I get continuity to ground, and also continuity to the dk blue wires.

The purple load wire from the flasher to the turn signal switch has continuity from end to end, but not wire to ground. Ditto for the pink switched feed to the bus bar on the fuse box.

All that being said, I strongly believe I have found my dead short. The blue power feed wires to the relay i believe are also a dead short to the ground wiring in the dash. This is why the other 2 fuses arent popping on the same bus, they arent shorted to ground, and neither is the feed wire going in.

About a 2.5' run of wiring I will have to unwrap all the way to the convenience center and sort thru while on my back under the dash. Will be removing the "inconviencence" center from the firewall to get a look behind it. I have some old wire harnesses from a truck I junked. I think I will make and run some fused jumper wires with male and female spades to the relay itself not connected to the "inconvenience" center and test to see if my theory is correct and I can get the signals to work before unwrapping all of it.

So essentially to make a long story "short" no pun intended, I think I electrically "found it" but physically have to now "find it".

I am betting this pinched wire deal is the source of the random turn signal fuse popping over the last 18 years or so of my 26 years of ownership. It's now finally become a hard short to ground. If those blue wires dont go to anything else but the signal relay like the schematic shows, I may even just wire the relay out of the convenience center and let it dangle under the dash like the flasher relay does.

 

[Jglew82]

Good work man. Sounds like you’re right on its ass.

 

[Moparmat2000]

I still had a pile of wiring from the 92 dakota I junked, so I made a temporary wire around in correct color code to test this. Plugged the purple load wire into the inconvenience center, jumped the blue to the ign hot side of the bus bar at the fusebox where the turn signal fuse is, and ran the black to a dash ground. My fuse did not pop, and signals work great.

I call this a wire around because the dk blue power wire is pinched to ground somewhere in this 2 foot space and I am wiring around it. For now I am gonna button up the column, and tuck this up under there. But at least I know where the problem is for a later date permanent fix.

Wife had an issue with her old 2012 grand caravan fuel pump relay. Its soldered to the computer board. Dumb design I know. Was a factory kit to correct this. I ended up clipping the wires going into the board for the relay, and mounting an external removeable replaceable pump relay on the firewall. This is a similar work around.

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[Moparmat2000]

"Fixed it" !!!
for now.
Will have to find and fix the short. I bet the wire is pinched at the bulkhead behind the "inconvenience center". No reverse lights though since I wired around it.

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[df2x4]

Nice work! Glad you figured it out!

 

[Moparmat2000]

Thanks df2x4 . It's only temporary, but done up to be reliable just in case I dont get back to it for awhile. Honestly I am glad the wire finally dead shorted. Before now it would randomly short to ground, pop the fuse then it would quit making a short to ground. No way to trace if it's not ground shorted. I'd replace the fuse and have turn signals for maybe a year or so, then it would short and pop again. The last 6 months it was now popping fuses pretty regular but would be ok as soon as I replaced the fuse. I am guessing the insulation finally rubbed a bigger bare spot somewhere for a continuous dead short. Finally now that it became a true dead short , I was actually able to take an ohmmeter and start checking and narrow it down. Its narrowed down alright. To about a 3' length of wire that's wrapped in a wire bundle about 1&1/2" thick lol. The good thing is all it cost me was some of my time and a bunch of troubleshooting. The wire around I had everything. It was just a matter of putting it together after figuring it out.

 

[Erik the Awful]

Good work!

I spent all day at work today trying to figure out why I have 12v at the starter solenoid on a diesel generator, and a good ground, but when you hit the start button, nothing happens. You can put a meter on the back of the start button and see 12v, and it goes to 0v when you press the button. You can jump from the hot on the starter to the positive coil post on the solenoid and it starts. Tomorrow we're going to dig into the harness and see which wire is broken all the way though except for one thread. Electrical troubleshooting can be a real b****.

 

[Moparmat2000]

Good work!

I spent all day at work today trying to figure out why I have 12v at the starter solenoid on a diesel generator, and a good ground, but when you hit the start button, nothing happens. You can put a meter on the back of the start button and see 12v, and it goes to 0v when you press the button. You can jump from the hot on the starter to the positive coil post on the solenoid and it starts. Tomorrow we're going to dig into the harness and see which wire is broken all the way though except for one thread. Electrical troubleshooting can be a real b****.

Yes it can. That's why this problem was an annoyance where your driving along and all of a sudden you have no turn signals. Put in a fuse they work fine again for awhile. If there is no ground short, no real way to isolate it and hunt it down. A buddy of mine at work is an aircraft electrician. Every ******* wire is white with tracer numbers on it. Main wire bundles running fore and aft in the fuselage are 1" to 2" in diameter and are several. I dunno how he figures that **** out, but he cant weld or fabricate for ****. We all have our talents I suppose lol.