Electrical system meltdown?

[AZMike]

Hello,
Had a bad battery - would not start the car all the time and would randomly die on me. I replaced it with a new one and still have one of the symptoms: When I put the key in and trun it to 'on', the dash lights and the running lights outside flash rapidly (about 3 - 4 times a second). This goes on for 10 - 30 seconds and will often quit - sometimes it won't and I have to take the key out and try again. I can hear a relay on the passenger's side of the car inside cycling with the lights. The power to the DIC is cut each time it cycles as well - I'm really worried about the damage this rapid cycling of power can cause. The car will not turn over or start while this is going on. To top it all off, when I do get the cycling of power to stop, it doesn't show any codes. I hope I have not damaged anything expensive with the bad battery, but it looks like some major electrical problem has occured.

Please help me! :ugh I'm out of warrantee, and I know the dealership up here will just start throwing (expensive) parts at it since there are no codes.

 

[Patrick]

Hang in there, Mike. I think this is one for C4C5Specialist. The fact that you aren't getting any codes is the real mystery. I wonder if you have a bad alternator?

-Patrick

 

[AZMike]

A bad alt would probably explain the dead battery. It would not hold a charge anymore so I replaced it. Could the alt explain the flashing of power though?

I do get intermittant 'low voltage' messages on the DIC, but no codes.

 

[Patrick]

...Could the alt explain the flashing of power though?

As I said, a good question for C4C5Specialist. I'm sure Paul will be along in the morning, but as others have observed, when the electrical systems in C5s experience problems, they can get "spooky."

The Alternator may not the whole story here, but I'm willing to bet it's a significant part of the plot.

Hang in there, Mike, we'll get to the bottom of this.

-Patrick

 

[c4c5specialist]

HI there,
First thing is first, make sure your battery terminals are tight to 11 ft lbs.
Next, have you had any modifications done?? anything at all??
Any service done to the vehicle in anyway???
This is key to helping in the diagnosis.
Allthebest, c4c5:bang

 

[AZMike]

Hi c4c5 - no service done lately - this started out as an intermittant problem with the car dying when cold a few weeks ago. Now it's this. The battery cables are nice and tight and free of corrosion, so I think I've got that one eliminted. I have not checked the various grounds yet though - I plan on doing that soon - when I get the time. The only mods to the car are an aftermarket stereo and a blackwing intake. Otherwise, it's bone stock. The AMP, however, is wired right into the battery - the connections are behind the contact posts on the battery - not in front.

 

[c4c5specialist]

Hi there,
So, how did you attach the amp to the battery, an eye terminal??
You should never attach an amp this way.
You should use a battery source when the ignition is on only, and then junction off the underhood electrical center and provide a switched relay to supply ground when the ignition is turned on.
Allthebest, c4c5

 

[AZMike]

Yes - the AMP is directly to the batt on ringed connectors. The amp power switch is wired in thru the radio, so the amp is off when the radio is. I was careful to go to a shop that is actually owned by a Vette driver. Do you think the AMP could have fried something?

 

[DRTH VTR]

What would be the advantage of changing the way the battery is wired? What was that supposed to have accomplished? Just curious...

 

[AZMike]

Well I checked the grounds and cables - no problems there. The car completely drained a brand new battery in a week, so there's something going on there. I charged up the battery, but the car won't start - just turns over, but gets no fuel or spark. I'm going to have it towed to the dealer - fortunately, they have a Corvette tech here. Unfortunately, I'm out of warrantee.

 

[AZMike]

Good news - I'm out for less than $500 to fix it. The ignition switch is the culprit - it's gone bad. This likely was the cause of my stalling issue a while back as well. I thought something really expensive got toasted - I'm pretty releived to only be out $410 or so. :cool