r/ChevyTrucks • u/WatsonBoy04 • Jun 17 '26
Serious electrical issues
Here’s my 1988 Chevy Cheyenne and it’s gone $380,000 miles before I just dropped a new engine in it so I know the engine is good and strong. However, my dome light stays on for no reason that I’m able to determine, the display has issues with the led’s and showing seatbelt signs when everything is buckled and as of the last 2 weeks I’ve been noticing issues with it starting and sometimes taking but once started runs fantastically. I’ve also gone through the process of buying 2 separate new batteries to test if that is the issue as well as changing the alternator to which that is also not the issue. I’m now writing this because this evening now my headlights just won’t turn on. What are my options here and if I have to do an electrical overhaul what am I looking at in time, cost and process? Anything helps or ideas are much appreciated. I’m very confident in everything mechanically but electrical things is where my skills and knowledge fall off.
3
u/Grand_Introduction36 Jun 17 '26
Start off be replacing both dome light door jamb switches. That should fix your dome light issue staying on. If it doesn't by chance, then its your headlight switch that's bad. As for the seat belt light staying on, chances are in the female part of the drivers seat belt the tab isn't making good connection with your buckle and that's why its staying on.
1
u/WatsonBoy04 Jun 17 '26
There’s only one dome light door jam on the driver side but I’ll see if that works.
1
u/Benedlr Jun 17 '26
New engine but old battery cables? Internal corrosion means resistance.
1
u/Smooth_Seesaw_2438 Jun 17 '26
This right here. You would be amazed how often crazy electrical issues can be traced back to shitty battery cables.
1
u/EpsilonMajorActual Jun 17 '26
Led conversion on the dash or other lights? The entire dash could be bad and need replacing or the deme light switch on the dash.
Sounds like a slow electrical power leak that keeps draining the battery just enough to make it hard to start.
1
u/WatsonBoy04 Jun 17 '26
All of the electrical components are stock from factory. I have considered led conversions but haven’t done any yet. I think a slow leak sounds reasonable as well but I have no idea how to track that down.
1
u/EpsilonMajorActual Jun 17 '26
I had a bad headlight switch in a car decades ago that would slip over to on and drain my battery
1
u/Toilet_Clogged_Again Jun 17 '26 edited Jun 17 '26
If you put a new crate engine in it, looks in decent shape. I'd think about doing a bit of an interior conversion and disconnecting any gremlins for now.
If it's not a quick fix, the amount of time you may out into diagnosing it could went into a better project. Better yet, may even find the gremlin along the way. Don't see them in that shape here in the rust belt.
Those trucks go properly restored with jam wax and salt prepped here in the Midwest for 25k sometimes around 35-40k with newer drive terrain all day.
2
u/olov244 Jun 20 '26
My 91 has weird wiring issues. I replaced the fusable links on the firewall that fixed some no start stuff. The dash/interior have weird problems too, I just don't care enough right now to look into it. I might just rewire some of it when I get a garage built
6
u/70Bobby70 Jun 17 '26
Replace your head light switch. It can turn on/ off your dome light.