Blowing Turn signal fuses when put into reverse

[knuckledrager]

Hey Everyone! My 1984 K20 (350 sbc, 4-speed auto) keeps blowing turn signal fuses when I shift into reverse. I've changed out the neutral safety switch, and inspected the wiring from the tail lights to the fuse block. Everything looked good no burns, cuts, or breaks in the line. Headlights and hazards still work just no reverse or turn signals. Am I missing something? Any help or tips appreciated thank you!

 

[Ricko1966]

When and how did this problem develop? What recent work has been done to the truck

 

[HotRodPC]

OK, so that's simple. Don't use reverse. Always park where you can pull through. FIXED !!! Ain't this place great? We can fix anything here.

So you think it's the back up lights coming on that's causing the fuse to blow? Look under your dash along the steering column and look for any chewed up wires from like a rodent.

Do the E flashers still work after the fuse blows? How about brake lights? Do they still work after the fuse blows?

 

[Turbo4whl]

Do the E flashers still work after the fuse blows? How about brake lights? Do they still work after the fuse blows?

Hey Hotrod, E flashers and brake lights are hot all the time. The turn signals and backup lights are key on and they share a fuse.

@knuckledrager You looked at everything? Remove both backup light bulbs from their sockets, look for damage or a shorted bulb. Engine running, try reverse without the bulbs and see if the fuse burns.

 

[HotRodPC]

Hey Hotrod, E flashers and brake lights are hot all the time. The turn signals and backup lights are key on and they share a fuse.

@knuckledrager You looked at everything? Remove both backup light bulbs from their sockets, look for damage or a shorted bulb. Engine running, try reverse without the bulbs and see if the fuse burns.

That's right. Just want to make sure they're not crossed up in the tail light area. I wasn't for sure though if the BU lights and TS shared a fuse though. So that's a big help in narrowing down the issue. So with that info, now we know, go right to the BU lights and start there since that's what likely blowing the fuse. And so that could be all the way to the BU light switch under the dash, but I'd guess it's going to be at the tail/brake light area and why I'd start there. Might try taking 1 back up light bulb out a time too and see what happens. Now just cuz the light bulb is out doesn't necessarily mean anything cuz it all depends on where and what the short is. But if you pull 1 bulb out and the fuse quits blowing, then you know which light to work with first. As said, it might not even tell you a thing. The short could be long before the bulb so the bulb being out may not even make a differecne either way. All a process of elimination til you find it.

 

[Ricko1966]

Replace the fuse with this,it's a 194 bulb and socket. When the light goes out you found your problem.Its easier to check than the fuse and will save you lots of fuses. Put it in the fuse box do what makes the fuse blow it will come on when the short appears,shake any harness you can grab or have a buddy shake or have a buddy watch,watch for blinking light. Your short is in that harness. Start taking things out of the circuit one thing at a time until the light goes out,when the light goes out you found the problem. Lacking a buddy just make a light with longer leads.

 

[knuckledrager]

The recent work that has been done is spark plugs and wires that was about 2-3 weeks ago so I’m not sure if it was that but I’ll look into it. I’ll try running it without the bulbs and use the 194 bulb while shaking the wires in today or tomorrow to see if that helps locate the problem. Thank y’all for the help!