Starter heat soak

67Dart273 said
All right "massive cable" does not tell me much. Your idea of "massive" and mine might be different

Detail the path from battery to starter. Is there a disconnect? Second solenoid?

What is the ground path EXACTLY. Might be as simple as a poor ground between engine/ body/ battery.

Before you do anything, and after the car as sat awhile (to bleed off surface charge) measure battery terminal voltage and post it here. Maybe? the battery is down

Clip your meter to the starter big main terminal on the solenoid, and to a good engine ground. Crank the engine and read the meter. No disconnect the coil wire and ground it and check it again..........starter may be "kicking" on the starter. You need "accepted" minimum of 10.5V and anything below 10V is just not gonna fly

Thanks for the fast answers!
The battery is not the problem as i tried it already with another bigget one.

The cable coming from the battery to the front is 50mm2 (about 0 gauge) then splits into two 35mm2 (about 2 gauge) - one goes directly to the starter and the other goes to the big bolt of the starter relay.

I just looked at the ground cable from the battery to the frame in the trunk and the ground cable from the engine to the firewall, they seem fine and thick enough i think about 2 gauge aswell.
But I will double check that tomorrow by putting the bigger battery with starter cables + directly to the starter and the - directly on the block.

I will do the volt checks aswell and will let you know!

Thanks, Laurin