Something is Burning


#1

1991 Buick Regal.

Well, one problem after another now.

I’m driving at night a few days ago and all of a sudden the lights on the instrument panel go out. The headlights are still on and the radio is still playing.

So I click the headlights on and off and the instrument panel lights come back on. The next night this happens again. This time I just give the headlight switch a little jiggle and they come back on. Tonight they go out again, jiggle the switch and they come back on. They go right back out. Jiggle the switch again and they’re on.

I drive for another five minutes and now I smell plastic burning; it’s the typical electrical/wire short smell. I turned the interior lights on and there was no visible smoke.

I’m going to try and pull the dash tomorrow and see what’s going on in there, but they want $400 for an OEM replacement switch! I found some used ones online, but I’d have to get them mailed from a junk yard for about $50 bucks.

So I’m wondering, is there a easy/cheap way to rig a headlight switch in the interim so I don’t have a fire in this thing? I don’t understand why a headlight switch has so many prongs on the connector.

The only caveat is that the guy who had this car before me rigged the ignition through the headlights (I was told as some kind of security feature?) so that the car will not crank unless the headlights are on. Maybe/hopefully some shoddy wiring on that is just causing an arc. What a mess.


#2

It sounds like the headlight switch is on its last legs. When a switch or electrical connector (including the outlets in your home) gets worn to the point where it is making a poor connection, you end up with higher than normal resistance. Electricity flowing through resistance=heat. The added heat causes oxidation of metal components, and arcing can deposit carbon, which=more resistance and more heat. Eventually the plastic body of the connector or switch can melt and even catch fire.

At no point is the amount of current the circuit is designed to carry being exceeded, so the fuse won’t blow or the breaker won’t trip. (unless the switch melts enough to cause a direct short) This mode of failure is sometimes called a “glow fault” and is rather insidious and sometimes hard to detect until you have a fire in the making.

Added to the situation is someone of unknown understanding and skill that has apparently modified the wiring of your car. At the very least I would inspect/replace the headlight switch and associated connectors. You may need a skilled automotive electrician to assist in diagnosing the problem and restoring the car’s wiring to its original state.

I would also consider either disconnecting the battery at night or not parking the car in your garage/near your house until this is fixed, just to be safe.


#3

Considering the previous owner rigged the ignition through the headlights

I’d try and un-do this kluge and fix it right. The extra current draw through the headlight switch for his “security system” may be the reason it failed. GM headlight switches are usually pretty robust.

I wouldn’t add another kluge to make the headlights work on top of the one you already have.

Can you say Electrical Fire? Sure! Sure you can!


#4

“The extra current draw through the headlight switch for his “security system” may be the reason it failed.”

+1 to Mustangman’s comment.


#5

+2 to Mustangman’s comment.


#6

I agree with all of the above.

Point is I’m not spending $400 on a switch. Even just a standard metal rocker switch under the dash if I have to. Guess I need to find the switch schematics.


#7

There is one print for without running light and 2 for running lights.


#8

You can spend less ( 292 or 254 ) for a new switch at McParts stores like Auto Zone.
There are two choices and you’ll need numbers from the old one to buy the right one.
But I concurr with the others.
The oddball setup has caused the problem.
Repair it back to original.


#9

All the OEMS I’ve seen are about $400.

Anyway, still a crazy amount for $20 worth of materials. I think I can make a switch for about $14.


#10

Who needs a switch!!!

The wifes been nagging for you to take her out more. Let her hop into the passenger seat and hand her two wires and tell her to hold them together.
Maybe she’ll buy you a switch!!!

Yosemite


#11

So I went to a highly rated local auto electric shop and had them take a look.

Guy said the starter wiring is not an issue as it’s just connected to a relay switch and not drawing any power from the headlight switch or line.

It seems to be a short in the Parking Light button, but it can’t be major (yet) as he couldn’t smell any burn and the cavity and switch casing was fine.

He agreed that 100’s of dollars for a switch was crazy. I told him I found a few used ones online from $10 to $40 and said I should just go with that, even if I have to purchase a few of them to get a properly functioning one. Or I can bring it back later and have them wire in a manual switch for much less.

I had him leave the dash face off and the mounting screws for the switch out in case there is a major failure/short; that way I can just yank it and chuck it if I had too.

Anyway, go see these guys if you’re in the Detroit area: http://www.cartalk.com/mi/utica/134150/marvs-auto-electric-repair