The other day I took my wife out on a date for the first time since our son was born 7.5 months ago. So we took the Corvette. On our way home, The Chock and Battery lights flickered on and off. The lights would get brighter the more gas I gave it. Then we heard a buzzing sound coming from the console area. Before we got back to the house, the engine was pulsing like the ignition was cutting out.

I crawled around under the dash looking for loose wires and found the key in/seat belt buzzer module was unplugged from the connector on the fuse block. I plugged it back in and checked the connections under the dash and in the engine compartment. Then the problem went away. Until this weekend.

I replaced the fan clutch then started up the car to make sure that everything was bolted back up correctly, etc. It all looked good so I closed the hood and hopped in to back it back into the garage when the old Choke and Battery lights came back on. This time, full strength. And the buzzing was even louder.

I pulled the carpet piece off of the driver side of the tranny tunnel so that I could see what was buzzing. Turns out it's the choke relay. It must have been opening and closing very quickly and with a lot of force because it was vibrating like a bee. I removed the relay to make the buzzing stop but both of the warning lights stayed on. I disconnected the choke wire from the carb and the Choke light turned off but the Battery light is still on. Sometimes it pulses in sync with the blinkers.

And both of the lights get brighter when I turn on accessories (window defogger, radio, A/C, power windows, etc).

Occasionally the Check Engine light will come on for a few seconds then go off.

On my way in to work this morning, the Battery light was off for the first 10 minutes or so then came on right as I was pulling in to the parking light. The weird thing, though, is now my idle speed is high (1500 RPM instead of around 750).

These gremlins are driving me nuts!

Any ideas?

Classic symptoms of a bad ground somewhere.
Your mission, Mr. Phelps, should you decide to accept it, is to find that ground...this post will self destruct in 10 seconds...



or not...

Leave the choke unplugged, but put the relay back in. The choke and the alt(batt.) lite are connected in the system, so if there is a problem with one, both lites will shine. See if that helps the symptoms any...
The problem may be the choke coil is grounding out once it opens fully.

Are there prime suspects for the bad ground? Trying to trace wires under the dash is a bit crazy. The engineers had to fit 10 pounds of  into a 5 pound bag...

Also, do you think the relay is bad?

Check the battery cables on both ends and the frame grounds first.

Scott

Scott got what I for-got...
The thing that is so specific is the alt AND the choke lite on. The lights getting brighter as you add to the load "(window defogger, radio, A/C, power windows, etc)" points to a ground problem. You may very well have two separate gremlins at play here...
I don't think the relay is bad, per-se. Just re-acting to a fluctuating load on it. If it is buzzing, it is being told to do it, by way of fluctuating power TO it, or there is a partial ground in the wire to the choke, or the choke itself. If you unplug the choke wire, and re-install the relay, and the buzzing goes away, and the lights go off, then you've narrowed down the possibilities to the wire, or the choke itself.
The alt light issue could be just a loose connection at the batt, or the back of the alt, but also a ground cable at the batt, on the frame under the batt box, or from the frame to the engine on the pass side, by the engine mount area.
You may also need to check the grounds in the console area for the gauge cluster, as they seem to have a few problems after being moved around over the years by people doing other repairs in the area.

First off, thanks for all of the tips! You guys are great!

Last night, I popped the choke relay back in but left the choke wire off. Then I removed, cleaned (til I saw shiny metal) and reinstalled the small grounding strap near the radio mast, the main ground wire under the battery box (that was fun) and all of the connections on the alternator. No change. The battery light stays on nice and bright and the choke relay still makes racket off and on.

I decided to remove the console and center instrument cluster to check all of the connections behind there. However, I couldn't figure out how to remove the cigarette lighter from the console panel (main wire is disconnected but can't get the socket off of the panel). Haynes manual just says "Remove cigarette lighter assembly." Nice. Also, do I need some special tool to get disconnect the center cluster from the radio? I was going to just leave the radio in place and check the gauge wires...

I'll check the frame-to-engine ground tonight.

Thanks again!

Corey

Well, all of the main ground points are fine but I still have the same problem. The voltmeter stays around 15V the entire time, no matter which accessories are on or off. Do you think a bad voltage regulator would cause this kind of problem? How can I check for it?

Thanks!

Corey

Buzzing choke relay and battery light = bad rectifier diodes in the alternator. AC voltage is what's causing the choke relay to buzz. KOPBET2007-08-13 12:27:53

I guess I'll be swinging by Autozone after work then... I gotta get this craziness straightened out. Thanks, KOPBET!

[QUOTE=LilRed81]I guess I'll be swinging by Autozone after work then... I gotta get this craziness straightened out. Thanks, KOPBET! [/QUOTE] KOPBET2007-08-13 12:33:49