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Electrical Issues HELP!!!!!

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Old Sep 18, 2007 | 09:01 AM
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Default Electrical Issues HELP!!!!!

I replaced the starter and connected all the wires (power, ground and signal wires) correctlyand even had a buddy that works on vettes come over and check the wires for me. He said everthing was connected properly/correctly so we bolt up the headers, put on the plugs, etc. We go to fire up the car and it fires up perfectly, volts were at 11.6-11.7 for a few seconds and then dropped to 11.5 and stayed there. I drove the car around and a little ways down the road, the voltage started to drop and dropped all the way down into the 8s. I get the car back home in the garage, disconnected the battery and checked to make sure the power wire was tight. I tightned the power wire b/c it was kinda loose and then I go to start the car again to see if the voltage goes up to 13.1 and it doesn't register any voltage at all. I hit the the unlock button on my keyless entry keypad and all of a sudden I get this humming noise coming from the fuse/relay box. Then the door locks started locking and unlocking themselves and my keyless entry keypad doesn't work. What is going on. I don't understand what is happening?
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Old Sep 18, 2007 | 09:20 AM
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wow, thats weird. I don't have a whole lot of experience with the C5 electrical system except for the fact I know it has issues. Mine was doing some funky stuff when i first got it but relocating most of the grounds to one central location seems to have solved the problems.

Did you try the obvious thing of pulling the NEG battery cable and resetting the ECU? There are capacitors in the ECU so after you pull th NEG cable you should put the key in the ignition and turn it to start for 10-15 sec to drain the capacitors. Also check all your ground connections and make sure they aren't corroided.
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Old Sep 18, 2007 | 10:44 AM
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do you think I could have shorted my electrical system or fried my PCM?
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Old Sep 18, 2007 | 11:00 AM
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I would say to take off the alternator and take to a autoparts store that can test it for you. Sounds like the alt. is bad and is running the car off of the battery, meaning it is just draining the battery power. The reason everything is going nuts is, there is not enough voltage to run the pcm and all the sensors at one time. Charge your battery back up also.
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Old Sep 18, 2007 | 11:44 AM
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Originally Posted by scramblerman
I would say to take off the alternator and take to a autoparts store that can test it for you. Sounds like the alt. is bad and is running the car off of the battery, meaning it is just draining the battery power. The reason everything is going nuts is, there is not enough voltage to run the pcm and all the sensors at one time. Charge your battery back up also.
alternator is brand new, i just put it on the car a week ago as well as a new battery last week. Do you think I could have had a loose ground on the starter which caused the battery to drain?

Let me see if I have this correct. There is one signal wire, 2 ground wires and 1 power wire correct? Or is there 3 ground wires, 1 power wire and 1 signal wire?
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Old Sep 18, 2007 | 12:49 PM
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Originally Posted by c5_ls1_6spd
... as well as a new battery last week.
This same thing happened to me, just after I put in a new battery. Ended up that the posts were not tapped deep enough and the bolt holding on the battery cables was bottoming out. Since the cable wasn't really tight, it would be intermittent. I put a star washer between the cable and the battery post (I was on the road) and it worked fine. It's been a couple months and I still haven't gone back in there to fix it right. LOL.
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Old Sep 18, 2007 | 01:22 PM
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Originally Posted by c5_ls1_6spd
alternator is brand new, i just put it on the car a week ago as well as a new battery last week. Do you think I could have had a loose ground on the starter which caused the battery to drain?

Let me see if I have this correct. There is one signal wire, 2 ground wires and 1 power wire correct? Or is there 3 ground wires, 1 power wire and 1 signal wire?
If I can remember right, 1 heavy gauge wire-Hot from battery, 2-signal wires and i think 1-smaller ground wire.

I highly doubt that a loose wire on the starter caused the battery to drain. After you charge the battery back up, check and see what the voltage is. Drive the car again, watch the voltage guage. If the alternator works that gauge should read close to 13 volts, no matter if the a/c, radio, blower motor is on. If you do this and the voltage doesn't go back up, you need a new alternator. I know you say it is new, but that doesn't mean that it is any good. Also check the connections behind the alternator. One hot red wire and a plug with two wires if memory serves me correct.
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Old Sep 19, 2007 | 01:27 PM
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I had a bunch of crazy stuff happen when I connected the positive cable to the battery after the negative....

I undid the negative and waited a minute and connected it back up and everything was fine.

Has to do with the way the capacters and computer gets charged I was told...

That being said it took me 9 months and replacing alot of good time, parts and frustration to diagnose a bad traction control and power braking module..
Damn electrical gremlins...good luck
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Old Sep 24, 2007 | 02:07 PM
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Originally Posted by dmiz0420
I had a bunch of crazy stuff happen when I connected the positive cable to the battery after the negative....

I undid the negative and waited a minute and connected it back up and everything was fine.

Has to do with the way the capacters and computer gets charged I was told...

That being said it took me 9 months and replacing alot of good time, parts and frustration to diagnose a bad traction control and power braking module..
Damn electrical gremlins...good luck

Can you tell me more of what it was doing and how you found out it was the tcs and power braking module? I have been trying to find my problem for over a year w/ no luck. All of a sudden my tcs, abs, and tach all quit working. Now my tach will sweep with the 1st key on and then nothing when the car starts, also as soon as it starts I get a service traction system and abs inop lights and readings on the dash.
Its killing me, its been to 2 different shops w/ no luck.
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Old Sep 5, 2008 | 02:36 PM
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I have a switch problem, when I start my 04 zo6 none of my guages will work unless I slightly turn the key to the left? anyone had this problem! 04 lemans car low miles.
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Old Sep 6, 2008 | 07:43 AM
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Originally Posted by wcksz06
I have a switch problem, when I start my 04 zo6 none of my guages will work unless I slightly turn the key to the left? anyone had this problem! 04 lemans car low miles.
that sounds like its in your ignition switch
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Old Sep 11, 2008 | 03:36 PM
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Alternator gets charge signal from the PCM.

Have you checked the out put at the back of the alternator and then the battery to see if the voltage was the same ?
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