1977 Corvette freak electrical problems
Thread Starter
4th Gear
Joined: Aug 2018
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1977 Corvette freak electrical problems
Hello. I've been working on my neighbors 77 corvette and I'm having a crazy electrical problem and was wondering if anyone knew of any common problems or suggestions
so here's the deal, this car has been off the road for 8 years and sometimes when you turn the key to ignition on it actually turns on but most of the time it doesn't. And if you try to actually start the car nothing happens and the car loses all power.
Some additional information, the negative battery cable has 12 volts so I know there's a short to ground somewhere but we have no idea where. we have already checked the ignition switch, neutral safety switch, and the alternator.
thanks for any help
so here's the deal, this car has been off the road for 8 years and sometimes when you turn the key to ignition on it actually turns on but most of the time it doesn't. And if you try to actually start the car nothing happens and the car loses all power.
Some additional information, the negative battery cable has 12 volts so I know there's a short to ground somewhere but we have no idea where. we have already checked the ignition switch, neutral safety switch, and the alternator.
thanks for any help
Pro
Joined: Nov 2016
Posts: 729
Likes: 118
From: Kelowna British Columbia
SO when you put neg meter lead on battery - and touch the positive cable to a ground you get 12 volts? If you have a short you will have to put an ammeter on and see how much current it is drawing? With ammeter in start removing fuses to see if you can isolate
Instructor
Joined: Aug 2017
Posts: 198
Likes: 90
From: Murphy, Tx.
Sounds like you may have a badly corroded negative battery cable connection either at the battery or at the frame..... or both. Keep in mind just because the outside of the connections may look okay, doesn't mean there is enough good contact to allow high current flow. Make sure all cable connections are clean metal..... and that there is no corrosion inside the battery cables.
Thread Starter
4th Gear
Joined: Aug 2018
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and that was my next plan of action, I just posted here to see if there was any super common C3 problem
Thread Starter
4th Gear
Joined: Aug 2018
Posts: 4
Likes: 0
Sounds like you may have a badly corroded negative battery cable connection either at the battery or at the frame..... or both. Keep in mind just because the outside of the connections may look okay, doesn't mean there is enough good contact to allow high current flow. Make sure all cable connections are clean metal..... and that there is no corrosion inside the battery cables.
Instructor
Joined: Aug 2017
Posts: 198
Likes: 90
From: Murphy, Tx.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
The negative post of the battery isn't connected to the frame. You either have a dirty connection or a bad negative battery cable.
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Pro
Joined: Nov 2016
Posts: 729
Likes: 118
From: Kelowna British Columbia
Electrical
is the battery new? Could be shorted and that could be why positive battery gets they to neg terminal and when you touch ground you see full battery voltage.
if new battery then you must have a short with 12 volt positive on ground. This you have to isolate
if new battery then you must have a short with 12 volt positive on ground. This you have to isolate
Thread Starter
4th Gear
Joined: Aug 2018
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Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
Take your booster cables and connect one of the negative clamps to a good bare metal spot on the engine, feed the cables through the passenger window and connect the other negative clamp to the battery. The problems will all go away.