[BlackTalon]

I previously posted in the Oct. 2/ 3 DE thread about a possible alternator problem. The "Seat Belt" light comes on for a few seconds here and there after driving the car for 10 - 15 minutes. When the AC is running, the fan sometimes surges. When driving during the Air and Space Museum/ Gainsville fun-run a couple weeks ago, the speedometer needle started jumping all around, usually for 4-5 seconds at a time.

This past Sunday, Dave Riley helped me try to track down the problem. We tested the voltage at the battery at both idle and 3000 rpms, and it was 13.8-13.9.

We started pulling the cables off the main grounding post, and the evaporator fan came on (while car was off, no key in ignition). We thought the fan may have been the problem, so to test that theory I cleaned the ground post and all five connectors, reattached everything to the post, and drove home with the fan "in the loop". After about 15 minutes, the Seat Belt light came on.

After I got home, I unplugged the fan connector. I drove the car to dinner a little while later, and the Seat Belt light came on again -- so the fan is not the problem.

The car is a stock '87 911 Targa, and the only electrical mods I know about are for the Alpine head unit and separate amp Vu installed for me at a Dorki get-together well over a year ago.

Any ideas/ suggestions? I was just accepted for the Oct. 2/3 DE (off the waitlist), so I need to be confident I can get this fixed within the next week -- even if that means replacing the alternator (which I would need Dorki-help for). There were previous suggestions for testing the alternator with an o'scope, but I do not fell confident the car will make it from Alexandria to Great Falls and back, and I reallly don't want to get stranded on the Beltway or GW Parkway.

**late addition - The alternator light comes on when the car is started.

TIA,