Hi,
I installed a starter heat shield today for my 1988 Camaro 305 TBI, I failed to realise that the positive feed to the starter was resting against the shield (bare metal contact).
I put the battery lead back on (made a big spark which confused me at the time) turned the ignition key and got a loud grinding sound and a small fire in the engine bay

I immediatley saw the problem as I described above and disconnected the battery, the starter positive wire had fused to the heat shield which had also partially melted.

I took the heat shield off, cleaned the charred plastic wire insulation away, I tried to start the engine again to see if it was ok and it just cranked over rediculously slowly.
I got under there and tightened the connections which I had removed earlier due to the heat shield install, at this moment I noticed that I had cracked the starter solenoid due to overtightening of the main wire clamp nut on the stud. The crack is from the base of the main stud to the edge of the plastic face section, only the plastic has cracked not the metal case part.

Now the question I am left with is why does the engine crank slowly now? is it a direct cause of the cracked solenoid or mainly beacause the battery was shorting for around 1 minute maybe 1 minute 30 seconds? would that be enough time to drain the battery which was otherwise fully charged?

It was fine before I messed around with it, will I need a new solenoid?
I should add that the solenoid stud now turns in its housing when i put a spanner on the nut, therefore I cant get enough torque to get the nut off.

I'd appreciate any help, thanks!

 

Take your battery and starter out and have them tested.

 

Your battery had more than enough time to discharge via the direct short.

I'd plan on replacing at least the solenoid, since it is that same plastic piece that holds the start contacts in alignment. It will probably fail in a short time from the stress of impact from the solenoid plunger.

I guess it really was 4-20...