Sonoma electrical nightmare with turn signal fuses.

stclemmons · August 9, 2016

New here. First post. Just bought 93 Sonoma 2.8 v6 5-speed. First things first with it. I NEED turn signals! I bitch about folks not using them and now when I take this out I am the moron who doesn't use turn signals!! Karma. When I got it, I replaced TS fuse. Problem solved. Sat in truck in carport and flipped them on and off for a while and then shifted into reverse and it blew instantly. Replaced fuse. Shifted into reverse. Blew fuse. One more time. Same thing. I am useless electrically beyond fuses....unless you count flux capacitors. Was told it could be related to tow package. Got under bumper and found MESS of wires tucked everywhere and tow plug wires were all cut. Thinking new bumper put on and nothing hooked up.

And it's like that all under the bumper...lol.

Not experienced at electrical but always want to learn. Any and all suggestions are welcomed no matter how basic or obvious they may seem. Thanks.

silverlite · August 10, 2016

Probably a short in your wiring between the fuse and your bulbs. Considering how bad your wiring looks underneath I would start with that first. You can usually Google for wiring diagrams for your vehicle too. I'm not much of an electrical person either as far as diagnosing systems. However, visual inspection is, of course a bit easier. A broken, frayed or exposed wire should always be repaired or replaced anyway.

If there is a wire that needs to be repaired or replaced make sure you use the same gauge (preferably same color too when possible) as what is/was there. Also look for previous repairs because sometimes they don't hold. If there's been a repair, reopen it to check it, then redo it. If there is more than one repair or break in the wire replace the wire. Depending on where the wire is coming from or through, you may not be able to replace the entire wire without tearing everything apart but you can still eliminate some extra connections. I usually leave all of the wire coming through the dash into the engine bay uncut until the first break & then run a wire from that point to lights etc. For some vehicles it's easier to redo the wiring or find replacements that have the correct connection to install the bulbs. Make sure the contact points for the bulbs aren't corroded, burnt or worn down to far. Make sure to use dielectric grease & don't touch the bulbs with your bare hands because the grease/chemicals from your hands can cause the bulbs to go bad too.

Hope this helps. Have fun.... Lol

Here's a link to other possible reasons/solutions:

http://www.doityourself.com/forum/passenger-cars-mini-vans-suv-service-repairs-no-trucks/485298-car-keeps-blowing-fuses.html#b

Ryan Wyatt · September 22, 2016

I would say it's not with the actual harness itself as it seems to be completely disconnected. But if putting the truck in reverse is what's killing the fuse you got the hot feeding the reverse lamp touching the chassis somewhere. Shouldnt be too hard to find

stclemmons · September 29, 2016

Just brief update:

Have had little time to work on it, but I did find another possible source. The backup/reverse light on passenger side is "broken". Previous owner tried to force the wrong type bulb into socket. Tried to replace with correct bulb, but it will go in but not do the "half turn" to catch it and stay in place in the socket. So, I figure I will have to find another socket and replace/splice and dice it into place. Nervous about that, but I did want to learn some electrical eventually.

stclemmons · January 3, 2017

UPDATE: I am posting solution because I hate following a thread and not knowing how/if things were solved.

It was the backup light switch on the transmission. Did a quick unplug and replug of connector and now I have reverse and turn signals with no more blown fuses.....for now...lol.

Thanks for help guys. Happy New Year!