Vette Problem

[Red73BB]

I drove my corvette to our club meeting on Thursday night, no problem with her, ran very well. After the meeting, she started right up. When I pulled the light switch she died. Tried to re-start nothing, completly dead, turning the key it was like there was no battery. After several minutes she starts again, try the lights and she dies again. Same thing after several of these, I started her and just let it run, brake lights work, directionals work. I turn in the parking lights they light. Pull out to headlight, shes dies, This time waiting 5 minutes still nothing., 15 minutes... dead.
Next day Took the battery to AutoZone and it checked out good, checked ground connections, good. The next day she starts up with no problems, pull out the light switch and she dies....
Suggestions????
Thanks, Gary

 

[Clairvoyant1332]

Try checking the wires going to and from the headlights. Sounds like you have a short in there. You might also want to try new headlights.

 

[Red73BB]

Thanks for the reply
I replaced the headlights about a month ago. I started to check out the wiring with a wiring diagram. It's going slow but I'm making progress.

 

[Yoda]

Gary,
Hang in there buddy. Your headlight problem sounds like FM.. seriously it does sound like a short somewhere to ground or somewhere somehow your ignition switch is getting open circuited when the head light switch is full on.

The delay in starting has me stumped... as well as the headlight thing. Keep us posted. I'll continue to congitate this problem. :confused

 

[Red73BB]

Still looking.

Still checking. Headlight switch is good, I thought it might be the vacuum stalling out, but that wouldn't explain the delay in starting.
I'm now looking at the after market security system and I think I might be on to something. The previous owner had someone install an elaborate system that would shutoff the fuel line and deaden the start system if the doors/hood or if the car was on a incline without the key in the ignition. That wouldn't explain the headlights.
I'll keep you posted.
gary

 

[wicky88s1975]

hey Gary, Another thing to look at is the vacumn system. If when you turn on the lights, a large vacumn leak, on the accuator side may cause the engine to shut down. It should be a large leak. Worth a check.

 

[Red73BB]

I think I found the problem... I removed the security system, a relay was wired the engine start circuit. Still doesn't explain the why the headlights would stop the engine and delay the start, not unless the circuit was back feeding thru the relay???. Now can start and turn on the headlights without the engine stopping. Did this in the garage, I will take her out for a extended drive and try the headlight again.
Thanks,
Gary

 

[69MyWay]

Go to the wires on the starter. That is where all the power goes from the battery terminal, to the rest of the car. You may have a fusible link going bad that has been overheated one too many times of the years. The exhaust really gets things toast in there.

I would suggest pulling the starter, dropping the fusible link wires down, and replacing them.

That should do the trick.


That also explains why it works sometimes, and not others.

Before you tackle that however, check out the ground going from the right front frame rail to the block near the fuel pump area. It is it weak, corroded, loose, etc, you will have the same problem. The voltage drain when you pull the lights will kill the engine/entire electrical system. I would first simply replace that ground wire, and make sure the ground going from the battery to the rear frame is clean, tight, and fresh.


Good luck!!!

 

[Red73BB]

Thanks!!!

I went to the starter to check the wires/ fuseable link and the ground connections. I have a heat shield for the starter/ soleniod and wires. Everything looks good. The ground from the starter was interesting, they used a peice of welding cable with climped connectors.
While there I found and exhaust leak the "donut" blew out on one side. The Chevy dealer and Napa didn't have a replacment, found one a Autozone, but it was smaller in height about 3/8" tall. It also leaks but not as bad. I heard someone makes one that is more fiberous and will form tighter for old exhaust systems does anyone know of this product???
Also the heat riser flapper between the manifold and pipe was stuck about half way I took a piece of 12 ga. copper wire and wired open. Do you see a problem with this???
Thanks,
Gary

 

[Bob Chadwick]

Gary,

I had an exhaust leak on mine as well and was told by my mechanic that it could introduce air into the exhaust system and depending on where it is, it could burn a valve.

Bob

 

[Stingray72]

I took that heat riser out. Mine was pretty frozen as well. What is it supposed to do, anyway?

 

[JohnZ]

The heat riser valve forces the exhaust gases from the passenger side cylinders through the crossover passage under the center of the intake and out the driver's side manifold when the engine is cold to heat the floor of the intake plenum for better rich mixture vaporization until the engine warms up and the heat riser valve opens fully; it also heats up the manifold under the remote choke coil to open the choke as the engine warms up. The downside is that the passenger side exhaust system doesn't get as hot as the driver's side, which usually results in the passenger side muffler rusting out earlier due to condensation, especially if the valve isn't opening fully when warm.

Unless you drive it in extremely cold weather, just wire it open and don't worry about it - you'll still have enough crossover heat to open the choke, and it'll equalize the wear on both sides of the exhaust system.

 

[MLGower]

I heard someone makes one that is more fiberous and will form tighter for old exhaust

Gary,

You can go to just about any Midas Shop and they should be able to sell you the proper donut gasket. Also, get some "Muffler Mud". It's an adhesive/filler for Exhaust gaskets and Donuts and apply it to the donut and pipe areas. It will help seal any leaks in the system.

Michael

 

[Stingray72]

Thanks for the info, JohnZ. I was stumped, but it all makes sense now. When I swapped my Holley spread-bore for a Q-jet, I got a model with an electric choke, so I don't have to worry about the thermostatic coil on the manifold.
I think I might have thrown that heat riser away. Even if I wired it open, the inside diameter was somewhere in the neighborhood of 1.5". It just made no sense to me to have one bank of cylinders more restricted than the other bank, especially since I'm taking the car in a more performance-oriented direction.
Your explanation has put me at ease.