Electrical meltdown—advice (and/or consolation) needed

corvair kid said:
Okay, I've been able to take a few initial steps this weekend. Mostly, I've pulled my dashboard apart entirely...on initial visual inspection, nothing is visibly melted, discolored, etc. The wiring to the radio is, as expected, a mess—the harness that plugs into the back of the radio had four or five wires coming out of it that don't go anywhere—but otherwise everything looks normal. I haven't begun testing individual wires yet. None of the fuses appear to be blown. I did swap in a fresh battery, and the car started just fine; when I disconnected the negative lead, it stalled, so it would seem the alternator is toast. I checked the gauge cluster lights, and only one bulb has a broken filament; most of my taillight bulbs are burnt out, but the light switch doesn't seem to be working anyway.
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Purple/violet wire burnt up? I'm surprised if so as that is fused (fuse 10). Unless you got some big fat amp fuse in there that wouldn't blow?
 
Possible new wrinkle/stupid question...I went to start installing my new alternator today. Haven't gotten very far yet—the screw holding the plug in to the back doesn't want to budge—but I discovered that the negative battery cable wasn't attached to anything. As you can see in the picture below, the strap is still attached to the body, but the cable was just kind of hanging out down by the alternator mounting bolt.

This doesn't explain anything, does it? The strap being grounded to the body is all that matters, right? As far as I can tell, this cable is entirely superfluous, but clearly I don't know for sure...
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a little bit of burnt wire makes a lot of smoke, and if it is in a cessna 172 at 3000 feet over the sea you may smell more than burnt plastic.......... don't ask how I know!
 
do you have another engine earth wire, similar size, between the engine and car or was that wire once attached to the engine? a missing engine earth could cause all sorts of problems, is there a missing bolt or nut within the radius of that wire?
 
Just spoke to the inimitable Bill Arnold, who assured me that there is a second earth wire at the firewall, making this one redundant. Good thing, too, because for the life of me I couldn't figure out where it might have come detached! I guess it's just been hanging out down there for who knows how long.
 
I bet that cable was attached to the alternator body thus relieving the sh!tty body connection from shouldering the load. I did a second wire from the battery cable to the alternator case then from the case to the block. Can't have too much ground!
 
in that picture of the loose battery ground, it can definitely have an impact on overloading solenoids and your starter circuit which draws a ton of amperage and cause hot ends to the wires under your dash, especially over a period of time. you can't ever have too many grounds, you'll end up with brighter headlight, tail lights, dash lights and way less strain on other ground connections. bmw also wired some of it's positive connections as "ground interrupt" so they are always hot.
 
I was trying to figure out why I was having intermittent starter issues on my 1983 MB 300SD. I had disconnected the ground cable from the starter. Don't know why, but I thought I'd twist the key to see what would happen. Smoke started pouring out from under the dash as the climate control became the route to ground for the starter. Don't know why, but turning off the key didn't stop it, I had to leap from the car and disconnect the battery. That cost me $400 for a new climate control module.

Grounds are important!

(turns out it was a bad starter, yeah, that was expensive too)

Ian
 
Finally managed to get the alternator out, with an assist from my father-in-law in town for the holidays, and...we may have found the primary source of the problem!

The screw that was stymieing me turned out to be one I didn't have to remove—d'oh!—as it was for the integrated voltage regulator, and my new alternator came with a new regulator. Once we figured that out and set about removing the electrical connections, we discovered...

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...that the wire that should have been held by the nut in the photo on the left had corroded (burned?) completely off of the connector!

Luckily our local Ace was still open even though it's Christmas Eve; we got a new connector, trimmed off the corroded wire, put on the new connector, hooked everything back up to the new alternator (maybe the old one was okay, but better safe than sorry), put the battery in after bolting that loose ground wire to the block via the oil filter housing, and the car fired right up!

Still no exterior lights (except for the reverse lights), but the wipers worked when we tried them and the ignition is obviously okay, so it's possible that a round of fresh lightbulbs/sealed beams are all that's left. I'll do some testing first to be sure, but this is the first wire I've found that looked at all compromised, so this might be the root cause of the problem.

What do you all think? Still plenty to do, but I've got the next week off work...it sure felt good to pull the car back into the garage under its own power.
 
Initial testing...fuses 7-12 are all fine; instrument cluster seems to be working; fuses 1-6 are receiving no power (changing the fuses doesn't fix), so no exterior lights....
 
teahead said:
Maybe load shedding relay is bad?
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Load shedding relay checks out okay.

HB Chris said:
Check your hazard switch, power goes from there to your light switch, might be the problem.
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I think the problem starts further back, since fuses 1-6 (all of the lights, essentially) aren't getting any power. The switch itself is getting power, since it runs through fuse 8, but obviously none of the wires that run between the hazard switch and the light switch are working.
 
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