Venom_1138

I got home about a week ago and when I opened my door, the courtesy lights (dome & footwell lights) failed to come on. Okay, blown fuse, no big deal. The next morning I left for work, and noticed that my stereo wasn't working either. At lunch, I decided to check my fuse panel and sure enough, the 20 amp fuse for my courtesy lights had burned out. I put in a new one and my lights immediately came on... and my stereo was working again as well? Odd, but everything seems to be working properly, so onward and upward, yeah?

Except, I drove less than 5 minutes and suddenly my stereo died. I got to where I was going, and again my courtesy lights weren't working. I checked the fuse and the brand-new fuse had burned out just like its predecessor. Well, crap. However, aside from these two systems, everything else in the car works fine: dash lights, headlights, power mirrors, power windows, etc.

So today, I pulled out my stereo deck, figuring that there was probably something screwy with how the P.O. had put it in. There were some... questionable installation techniques, like the fact that he had shorter "jumper" wires between the existing car wiring and the deck harness which were connected on one side by butt connectors and on the other side by twisting the wires and wrapping them with medical tape. That's right, not electrical tape, someone just raided the first aid kit instead. However, aside from that, everything looked to be in working order, save for the negative lead for the right rear speaker had come undone and the yellow (power, I believe) wire had lost its medical tape protector. I re-wrapped the wires with proper electrical tape, hoping that maybe one of those floating loose had maybe caused a short (though I was pretty doubtful). Sure enough, I made it about the same distance before the stereo died and I burned out yet another fuse.

I'm pretty confused at this point, because I don't understand why the stereo would die because the courtesy light fuse burned out... or for that matter how the stereo could be possibly causing the courtesy light fuse to burn out. According to the fuse panel, the stereo has its own fuse, so obviously there's something causing a short between the two. Plus there are 2 additional fuses for the stereo, one in the back of the unit itself and another in the line on the yellow (I'm assuming) power wire, so my thinking is if it was the deck itself causing the issue, it would torch either of those two fuses before the courtesy light fuse, so the problem must lie somewhere else. (this is just my logic, feel free to correct me if I'm wrong) Not to mention that when the fuse has burnt out, I've been driving and therefore none of my courtesy lights were even engaged.

Anyway, TL;DR - my courtesy light fuse keeps burning out and when it does my stereo quits working and I haven't been able to figure out why.

Other things worth noting: The P.O. had run a speaker wire (as in literally the wire you would use to connect a speaker to a home stereo receiver) from the alternator, around the engine bay, through the firewall and it terminates in a wire nut leaving it connected to absolutely nothing. No idea what it was for, although I'm planning on pulling it because... well, that should be fairly obvious, lol. Also, the wiring under the steering column is a total wreck. I don't know what he was doing, but there are several loose connectors. He bypassed the Neutral Safety switch by running a jumper wire between the two sides of the pigtail. I'd call some of what he did ******* engineering, except that I feel calling it that would greatly offend a lot of rednecks.

If anyone is a wiring/electrical guru, please feel free to speak up, because I am totally at a loss right now and I miss blasting some tunes while I'm driving.

Drew

iTrader: (58)

Just going to shoot from the hip here to keep things short and sweet. There's a series of orange wires that run all over the car. Those orange wires are 12v constant. One of the key things they power are the dome lights, but also things like the cigarette lighter, and the keep alive memory power to the stereo. Somewhere, somehow, that orange wire is shorting to ground. Easiest way to figure out where would be to eliminate possibilities. If you think it might be the radio, try disconnecting it. Take the cigarette lighter out of it's socket, make sure there isn't a penny, nickel, or dime in the bottom of the socket... Leave the lighter out for awhile and see if the fuse keeps blowing. You'll need to keep trying things to diagnose where the circuit is shorting.

You can refer to the wiring diagram in the GM Service Manual, and it'll show you everything that is on each fuse. That will give you an idea of what could be causing the problem, and give you a list of places to look.

Venom_1138

Thanks for the reply, I was going to disconnect the stereo and try from there once I get down to NAPA to buy some replacement fuses. FWIW, the cigarette lighter hasn't worked since I bought the car, aside from not being able to charge my phone, I haven't been bothered by it enough to make it a priority over the other things I've been trying to fix or otherwise improve.

I drove the car for over a month without issue, so whatever happened while I was driving home didn't give any warning signs or come as a result of any repair work I had done. I've been working 12+ hour days 7 days a week since the end of June, so I haven't even had time to work on break it, lol. Obviously this seems like it was something that was just going to happen in a matter of time, but it almost feels like something external caused it to happen.

The last 2 fuses both blew not too long after I drove down a 1/2 mile unpaved driveway; one happened right as I was reaching the end of the driveway and the other happened not too long after I pulled onto the main road. I think the first fuse might have blown just after I crossed a set of railroad tracks. I was talking on my Bluetooth headset, so I wasn't listening to the stereo enough to say 100% for certain. However, when I crossed the tracks, for a split second it seemed like my headlights dimmed, but then were right back to normal. I stopped by the store and noticed when I got out that the dome light hadn't come on. I figured the bulb had probably burned out, but when I got home a little bit later, I realized none of the courtesy lights were working, not just the dome light.

Hopefully that little bit of extra background info might help pinpoint something.

sofakingdom

iTrader: (1)

Blowing fuses when going over bumps = a naked wire or connector or something bouncing around and touching ground

Only way to find it is to examine EVERY SINGLE orange wire (the ctsy light circuit) until the bare wire touching the chassis is located. No real shortcuts unfortunately. Nobody out here is going to be able to tell you where the PO's peterpullers went.

Sounds like rather than "troubleshooting" this exact problem, the thing to do is to just CLEAN UP the wiring in an overall way. "Troubleshooting" a rat's nest hack job of steel (copper) wool and spaghetti is largely a waste of time: all you find is, that it's a rat's nest hack job of steel (copper) wool and spaghetti that you need to clean up.

As Orange said, the reason the radio goes out is, the constant batt feed that holds up the clock and station memory, also works the tuner. When it goes away no tuning occurs.

Lights dimming at the instant a fuse blows = a giant electric load occurred just at that instant. Well, duh... why else would a fuse blow, anyway?

Dykes should not be available for sale to the general public. A license test and also a general intelligence (common sense) test should be mandatory. I always tell folks, I don't know which one scares me the most; that "they" drive, "they" vote, and "they" breed; but I'd add to those terrifying things, that also "they" mess with wires, and "they" buy guns.

Venom_1138

Yeah, that was pretty much my initial thought as well.

Not going to lie, but I was really hoping not to have to go that route. Lots of wires in a space that doesn't even have enough room for me to to change my mind, lol. I was hoping there might be some common problem areas that I might be able to narrow down to, at least. Oh well, if I wanted easy I'd have just bought one that was already restored

Thankfully, aside from the stereo wiring harness, the alternator-powered speaker wire to nowhere, and the disconnected pigtails/receptors, he didn't do much else for custom wiring. It's mostly the factory bundled wiring that I'm really not excited about troubleshooting.

That makes sense though I still don't quite understand how that would cause this scenario. If the constant batt feed was gone, wouldn't it impact other systems like the dash lights as well instead of just the stereo losing all power? I'm not questioning your knowledge, I'm just trying to better understand how it all comes together that my courtesy light fuse blowing affects just the lights on that circuit and my stereo, but doesn't affect any other systems. I guess in my mind, to fix the problem, I need to 'think' like the problem.

Yup, and that's why fuses are nice to have... As annoying as this is, I still most definitely prefer it over an electrical fire.

Hopefully my days will start to slow down within the next week, because I think I'm going to have quite a few garage hours tracking all the wiring, unless I get lucky right off the bat.

mmadden55

dead ground short

sofakingdom

iTrader: (1)

The constant batt feed that holds up the radio is on the courtesy light circuit. These things all require constant battery. Not the dash light circuit, which is only active when the tail lights are turned on. Therefore when the courtesy light fuse blows, things on that circuit - notably the courtesy lights (duh), the cig lighter, and the radio memory - lose their power. Dash lights, on a totally different circuit, keep on working. Their feed that comes from the batt splits off LONG before the courtesy light fuse.

Yeah I know it's no fun exposing every inch of wiring and finding the short. If I knew of any other way, I'd be happy to clue you in. But there really isn't. Sometimes you can unplug things where there are junctions, and isolate the problem somewhat; but in the end, there's no substitute for just following the wires until you come to the failure. Instinct tells me that it's NOT something in a part of the wiring that's factory unmolested; most likely, it's somewhere in a place that the PO got his d***skinners into it. IOW, de-PO the whole thing, and you'll probably find the problem has magically disappeared in on the bargain, even if you didn't specifically observe the fault along the way.

Venom_1138

Ahh, okay. They DO share a common circuit after all. That totally clears that little bit of confusion up.

Yeah, I'm definitely planning on removing any trace of him from the car. I've been fixing his "handiwork" since Day 1, but I at least enjoy working on the car... when I can find the time, anyway. I just have to keep reassuring her that the bad man can't hurt her anymore.

Stuff like this is an annoyance because unlike the faulty starter or worn-out leaking weather seals, etc, there's no "Ah-ha" moment where you can immediately identify the problem and the solution. But then again, I did want a project car so this all comes with the territory.

Thanks for all the input. I'm sure I'm probably going to sacrifice a fuse or 3 hunting this down, but I'll update as I find anything or run into any new problems.

RBob

iTrader: (1)

One item that can help track this down is a small light bulb in place of the fuse. Use something like a 194 or 1156 bulb with two wires soldered to it. Then on the end of the wires either small fast on tabs, or use the terminals from a blown fuse.

Plug that into the fuse block in place of the fuse. Now, whenever the short is present the bulb will light up. Will need to remove the courtesy bulbs while doing this as they will be on with the door open.

Now you can move/shake the harness are various locations and see if the test bulb blinks on or off. This can really help in narrowing down the location of the short.

RBob.

DynoDave43

iTrader: (11)

Do you have the cigarette lighter in it's socket? They can corrode and short. If you have it, try driving the car with it removed (the lighter itself, not the socket). it's easy to try. Maybe you'll get lucky.

Venom_1138

Hey, that's a brilliant solution! That could really help cut down on my troubleshooting time, for sure. I've got a good handful of spare 194 bulbs from my LED swap, so I'll definitely be giving this method a try. Thanks for the suggestion!

The cigarette lighter socket is currently empty. I took it out to try and charge my phone on the trip home when I first bought it, but it looks like the fuse on that is out, too. I haven't really needed it for anything, so checking/replacing that fuse has been a pretty low priority so far. I'll double check to see if something stupid like a penny found its way in there (my wife blew a fuse that way on her Explorer about a year ago, courtesy of my daughter playing with the change in the cupholder), but I don't know if something making contact inside the socket would be able to affect anything if the socket already wasn't working, would it?

3.4 grape

iTrader: (1)

1) Disconnect stereo from courtesy circuit. Does fuse still blow? Yes?
Problem lies in courtesy circuit.
2) Removing stereo stops blowing fuse. Problem lies in stereo circuit.
Reconnect stereo directly to power source with inline fuse.
a) Fuse still blows. Problem with stereo, discard stereo.
b) Stereo works fine. Problem with wiring (most likely).

Drew

iTrader: (58)

I said it before, but I'll say it again... You need to find a good GM wiring diagram for your car and look in the fuse block section for the fuse that keeps blowing. You'll find pages that show EVERYTHING connected to that fuse, so you don't waste time looking at things that aren't relevant.



This is an 87 Camaro diagram, just an example of what I'm talking about. Try to find one for your exact car for best results. As you can see there's a lot of stuff running off that fuse. There are also a lot of connectors in the circuit that can be disconnected to eliminate a branch of the circuit from suspicion.

#2 REALLY look into the cigarette lighter socket for a coin. A corroded coin, in a socket full of ash can be hard to spot. It might keep you from plugging something into the socket, and the socket might not seem like it works, but the socket is still hot if it's connected. So yeah, it could be that stupid and simple. If nothing else you can pop the shifter trim plate out of the console and disconnect the orange wire from the socket.

henryd3

iTrader: (128)

When my fuse was blown and the dome light, etc and all that stuff on the same circuit didn't work I read on a thread on here that it's the lighter socket itself that shorts out and often is the cause for these issues. I unplugged it and when replaced the fuse lived and everything else worked. You can either leave it unplugged being careful the orange wire which is always hot is protected for shorting out anywhere or replace with a good one. Since then I've been collecting good used ones every time I run across them. Try it out, might solve the problem

Venom_1138

Welp, I forgot to update, but I found the problem. I followed the advice here and made myself a tester from some leftover 18 gauge wire, a couple of slide terminals and a leftover 194 bulb. However its usefulness was short-lived as I found the problem in 30 seconds. I plugged in my tester, and the bulb light up like it was Christmas eve. I figured I'd double check the cigarette lighter before moving on, so I peered into the socket. It was pretty dirty, but it looked like something was out of place, so I carefully probed in with my Leatherman and encountered what looks to be a broken part of a hair pin. It was stuck pretty good, but as soon as I popped it loose, it sparked a tiny bit against the side of the socket. I managed to get it out, and my tester bulb immediately went out. Popped in a new fuse, and it's been acting just fine ever since.

I'm guessing the grime in the socket was why my charger wasn't working and why the pin wasn't shorting out the system at first. The railroad tracks must have been enough to shake it loose to where it made the connection, and it partially fused itself in place, so it wasn't going anywhere without intervention from that point on.

So easy fix, overall. Many thanks to all who chimed in with their advice, you guys are awesome and make being a part of this community a great resource for so many things.

Drew

iTrader: (58)

Might want to look into changing the socket, if its that crusty. DORMAN 56458 looks about right, aside from the center post. I'd also keep a lighter, or get a plug to close off the socket when it's not in use to keep stuff from falling in.





{Photo Credit: Rock Auto}

DynoDave43

iTrader: (11)