[JohnE]

Originally Posted by oldman

My car for years has had a slow crank when hot problem.
1) with built engine and long tubes I did cook the starter and had to partially wrap starter and header.
2) for about 5 to 6 years it would crank slow only when hot, keep in mind I don't drive it much and it has a battery tender.
3) Voltage gauge was never really active but it was charging (note car has a complicated MPG charging cycle that there is a white paper on.
4) Even expensive load / charging testers pass the car (barely)
5) did the engine ground cable (help slightly)
6) Changed alternator, starter (again).
Not really an issue but it was starting to bug me.
7) tried adding a ground cable from battery to frame. Car instantly went into a no charge mode. Why. The stock wire is longer than needed because it is calibrated for the current clap.
8) Took cable and clamp out of my CTS, toss the second ground. Car has a good strong charge, slow crank after driving while hot is completely gone, it cranks faster now after driving while hot.

Take aways, the pennies on the dollar EPA current clamp charging ides is STUPID and it does not work on high compression V8 cars. The guy that added a ground cable from battery to frame solving his issue is just plain WRONG, which I knew but wanted to try anyway. You can use a generic current clamp for $30 from a CTS or 5th gen Camaro, or you can EBay a factory one for slightly under $100 and comes with the too long for a reason cable.

Can you elaborate a little more? what did you replace? thanks -John