LT1 Camaro electrical gremlin

[Richard Cranium]

95 LT1 Camaro. Mods ..... everything short of an LS1 swap, but all mods are LT1 style components, eg MSD Opti and coil with a new stock ignition module.

 

Hey guys, I wanted to run this past the group and see what the consensus would be. Last spring we finished putting the Camaro back together after swapping the trans and rear. To get the new trans in the engine had to come out.

 

After getting it all back together and everything reconnected, the engine would not crank and the ground strap running from the drivers side head to the frame became very hot. When that ground strap was disconnected the car started and ran.

 

Fast forward to this fall. I saw battery charge issues all summer, the car would not start strong, jumping it was difficult, etc... it's obvious there is something electrical going on and things are just not right. Took it out to school again and we put it up on the rack. The students noticed that with the engine running there was some arcing between the exhaust and the frame. When the engine is cranking we are seeing between 1 and 3 volts between the engine block and ground (not steady, somewhat random).

 

We've been over the wiring and the best we can tell there are no wires incorrectly connected, rubbing, shorting, etc... We suspect the starter may be shorting internally and routing partial main power to the block.

 

Any ideas?

 

Cliffs:

Car will not crank with ground strap connected and ground strap heats up quickly.

Car will run without ground strap, but has other electrical gremlins.

Block is being electrified.

[Rocky31186]

Still sounds to me like something is shorting out on the block.. I know you said you checked, but it still sounds like something is shorting out.

[AJ]

also check for pinched wires around the bell housing. i'm kinda thinking that you pinched something or you have something hooked up wrong that has tuned the engine into positively grounded instead of negatively grounded. the engine and trans mounts would keep it from shorting to the frame.

[Cordell]

also check for pinched wires around the bell housing. i'm kinda thinking that you pinched something or you have something hooked up wrong that has tuned the engine into positively grounded instead of negatively grounded. the engine and trans mounts would keep it from shorting to the frame.

 

This was similar to my initial thought. The ground strap getting hot sure sounds like a short on the engine to me, and I'd think it would have to do with the alternator or starter since those are the only two leads that don't have fuses to blow. Hook up the ground strap and see if one of those wires gets hot too.

[Patterson]

I would think its the starter. Or in that circuit.

[Green Bastard]

check the wiring to the starter to make sure no positive wires are touching the block or the bell housing, also couldn't hurt to check the starter solenoid wiring if its seperate from the starter (though I believe most gm starters have the solenoid on the starter, I've never worked on an lt1 motor) if that's not the case try disconnecting power from the starter and alternator (seperately of course) then test block voltage to figure out if either is bad or hooked up wrong

[AJ]

if the battery cable on the starter is on wrong it could cause an issue as well.

[Richard Cranium]

Thanks for the info guys, the shop has been pretty busy the past few days trying to get cars finished up before the winter break. The Camaro is not a high priority right now so it's on the back burner for a couple more days. We'll give all these a try and I'll let everyone know what happens. Thanks again.

[Richard Cranium]

And we have a WINNER! The starter was shorting internally to the block. Disconnecting the starter saw the voltage disappear, reconnect and the voltage comes back. New starter is on order.

 

Thanks guys.