I found it.. the cable to open the lid... the alt had a dead short. Good thing the battery had a low charge.

 

I'm stupid, I was trying to troubleshoot your electrical problem never thought about the mechanical cable....Especially, lately, the ground from the engine to frame seems to give TT owners lots of problems....Happy you found your problem Pat and please don't be too angry at your father

 

I got the engine bay open. And alt out. Alt seems OK. Retested for short. Not there now. May have melted away the short . Will check all underneath in the morning.

 

Never like to see one of our babies being towed due to a problem -- but if it has to be towed, I like the way you're doing it with another Porsche . Good luck with the repairs.

 

update. put the new alt in and still shorting out problem. found it last night. I had put new diverter valves in and they were aluminum not plastic like the original ones. behind the positive termainal in the engine bay it had worn off the insulation and was now contacting the diverter valves some times. the diverter valves were tight enough to make contact with something else to short out sometimes.

 

Wow good catch Pat!!!! Had the same problem with mine , the head of the new diverter valves was a lot bigger and had to provide space for the new ones. And it is tight in there!!!

 

I taped it up and put zip ties over the top. should be good now.

 

Great troubleshooting everyone. I am still new to the 996tt, threads like this one are of great value to those that end up with similar symptoms. Good stuff!