secrt0007agt

2006 Coupe.........A couple of times after starting my volt gauge goes below 12 volts and the "Service Charging System" light comes on.....then after restarting everything is normal.

Today I started up and the volt gauge pegged out to max, my radar detector came on flashing something like "too much voltage" or something and shut itself off. After restarting everything was normal.

I went for a ride and the check engine light came on......returned and got a P0690 code. While I was reading the service manual (car shut down for about 15 mins), the darn radar detector got power and came on for some unknown reason. The detector is hard wired to the rear view mirror and works great...... coming on at start up and shutting down when the car is shut down.

I have had some unknown draw down on the battery.....after about 3 days I find it dead., so I keep a trickle charger on it. I think that is one problem for the battery discharging.....hope it is the only problem. I have never noticed the detector coming on while the car was shut down, but this may be my discharging issue.......but what is causing this ?????

Bill Dearborn

The Service Manual diagnostic procedure has a lot of steps that require the command capabilities of a Tech 2 so it is unlikely you will be able to perform some of the tests described. I don't know how much experience you have in using Digital Voltmeters (DVMs) or fused jumpers but you could do some of the tests with those two tools.

The two potential failure points are the ECM or the Ignition Relay. Code P0690 indicates the Relay Ignition Output Ignition 1 Voltage
is shorted to a Voltage. Most of the diagnostic steps that result in a failed test outcome recommend replacing the ECM. However, the relay is a cheap part and like all relays is more prone to failure than solid state devices. Replace the relay and see if that fixes your problem. If it doesn't you have other issues and a trip to a dealership where they have better tools may be in the offing.

Bill

secrt0007agt

Hey Bill thanks much for the reply and I was out & about looking for an answer when you wrote. My thoughts (the relay) at first and certainly the cheapest thing, so my first purchase today was the relay. Not sure if that is the answer since this is a sporadic event, so after the relay I erased the code to see if that comes back again. I also stopped by the parts store and had them check my alternator, which was working (at that time) fine. I guess I will do some local driving and watch the gauges, then next week I will try to pick the local Corvette shop owners mind and try to get him to run some further diagnostics. Thanks again.

secrt0007agt

Took my 06 to a Corvette Specialist in Pensacola, somewhat reluctantly, but I was tired of my car doing crazy things, ie, all light blinking and flashing like the world was coming to an end, voltage spikes, codes, battery discharge and so forth. He hit the nail on the head just as I was explaining the symptoms, unknowingly, but right on. The possibilities were from fairly simple to some damn expensive things.

Turns out the positive battery cable, not up at the battery, but rather down at the starter had gotten brittle and frail after being exposed to excessive heat and was sporadically arcing causing my electrical nightmares.

New cable assembly (positive as well as negative) one piece assembly from GM fixed my crazy problem. The next time you have similar symptoms, please check the cables for shorts and/or damage.

PS. Apparently all the arcing and electrical issues fried a new battery too, but it was still covered 100% by AutoZone.

Dave S

Hmmm.....this is a good bit of info to keep in mind if electrical gremlins happen to strike.

SUB VETTE

That cable connection at the starter has been the source of many reported problems by other members - usually loose or corroded. Glad you found it and ended your electrical gremlin escapades