This morning was beautiful and sunny. Went into the garage and looked at the Vette and 442. Decided to take the Vette to work. Got in started it and sat their waiting for about 30 seconds to kick down the choke while admiring the 442. Then I see smoke on the top of the dash between the speedometer and tach and smoke also coming from underneath.

I immediately shut the car off, disconect the battery and grab the fire extingusher from the 442. (Oldsmobile show rules state that each car must have a fire extingusher). By the time I get back to the Vette thinking I'll push it out of the garage if it's going to burn, the smoke had stopped. I popped the hood and saw that there was no smoke there. I opened both window and with the battery still disconnected, took my 1.3 litre Ford to work.

Later, when I got home I got underneath to see if I could see any damage. Nothing! I hooked the battery back up. Watched for about 10 minutes. No smoke. Started the car, and in about 10 seconds smoke fills the cockpit. top and bottom Has this happened to anyone else? Perhaps I should start it, back down the driveway and see what happens. I bought the car for $4900. last year but it was apparised at $10,000 US by my insurance co. a month later. Perhaps I should collect, since I cant sell it like this. Too bad, the car is an L82 4 speed with every option execpt heavy duty battery.

Two months ago I had a new circuit board installed to get the tach going at a corvette shop. I wonder if they could have done something. But like I said that was two months ago.

The 442 is the same year (1976) as the Vette and it still has the original fuel pump, carb (never rebuilt) all body panels etc. and EVERYTHING works. The Vette is a higher end Chev, so I thought it should at least be comparable to the 442 in reliability. I suppose I could add a new dash wiring harness. Suggestions about this problem? Any help is appreciated.

 

Anybody?

 

I know that I was having problems with the a/c fan switch acting up. Would cut out on high and if I played with it could get it to work. One nite going to work with the a/c on..started to smell/ see smoke coming from the center portion of the dash. Instinctivly cut off the fan to the a/c and smoked stopped. Took dash apart and went for the fan switch..sure enough, the switch had made somewhat of a bridge between the high and med speed selector setting causing a ground and burnt the plastic case which inclosed the brass slide. Bought a new one and changed it out.

Wahlaa..no more problems! Get out the screwdriver and take dash apart and inspect the guages...could be something there or the fan switches...possibly. Hope this helps...Joe!

 

Thanks Joe. Good thing I cut the grass after work today, seems my Saturday is going to be busy. One dash coming off in the morning. Thanks. Ken

 

It is good that you shut it down before all the magic smoke got released. You may be able to save something. Once all the magic smoke gets out, it no longer works.

-Mark.

 

UPDATE:

Took the dash off this morning. As soon as the top pad came off I could see the wire (brown/white) that was causing the grief. There was almost no plastic cover over it. I took electrical tape and wrapped it. I think I will still change the harness anyway. Anyway, I started the car and watched. No smoke! Started it a few times more...no smoke. Went around the block, speedo and tach worked, still no smoke. Have started it many times during the day. NO SMOKE!! So, it's not as bad as I thought it was. So the universe is unfolding as it should. Thanks all.

 

WOAH NELLY!

I am not a 76 guru but I am an electonic engineer and I understand electrons pretty well.

Don't start or drive that car till you find the source of the problem. The Haynes manual I have (63-82) does list brown as one of the wiring colours going to the tacho. Follow my logic through. the reason things smoke is due to excess current. If there is a short circuit past those wires, even a partial short circuit, then you will have conisderable current going through those wires. The current produces heat and then melts the insulation. If you are lucky then you get smoke and nothing else. The worst case is the insulation melts then you get a larger short circuit with even more current and a fire!

Heres what you NEED to do:

1. Find what those wires lead to. You will need a wiring schematic (I got mine laminated from a vendor) which is available as a poster or in the back of the Haynes/Chilton manual. It is important you get one specifically for the year of your car. They did make changes through the C3s.

2. Find out why the fuses did not blow? I fiind it odd that the car would smoke up wiring before a fuse blew. Thats what they are for to protect against this situation. Make sure all the fuses are as rated. Also if you are buying new ones get fast-blow till you resolve this problem. Its possible the previous owner had a problem and put a 20A fuse in a 5A circuit. It does not solve the problem, just hides it.

3. Test the device (ie tacho) attached to the end of those wires.

If you need any help with troubleshooting shoot me an email.

 

you read that TSB to????? leave the batt un-hooked I don't want to read it went up

 

I also was wondering how you could get all that smoke without having a fuse blow.

Do all the guages work properly? I am pretty much in your camp tho, if wrapping those wires stopped the symptoms (smoke) and everything works I would go ahead and drive it (but certainly keep an eye on things.) HOWEVER, 2 precaustions I always follow and you should also definitely:

1. Carry a fire extinguisher in the vette (You probably figured this one out already??)

2. Always disconnect the battery when parked.

 

stingry, thanks for your post and offer. I think the best thing to do is to change the wiring harness. When I bought the car the owner said to me, that if I changed the harness 90% of the problems would go away. He said that he was going to do it but got fed up and just wanted to get rid of the car.

I have to go to Singapore and Australia for work in a few weeks, but I think once I get back, my winter project will be to change the dash and engine harnesses, just to be sure.

My Haynes 68-82 corvette book said that the brown/white wire is the "Feed ignition switch, accessory controlled - fused". Any idea what that is?

BTW, Comp I did disconnect the battery and PRND21, I have an extinguisher. Also the speedo, tack and guages work. The clock doesn't. Another winter project.