88 truck, runs great with the map unplugged

[lickmyburger89]

There are 5 ground wires that terminate near the coolant temp sensor on my 89 are all 5 there on yours?

I have the 4 going to the t stat housing and the battery ground on manifold. Is there an extra wire i'm missing or did you include the bettery cable in the grounds?

 

[lickmyburger89]

What does that mean?

My MTG2500 has a crappy rechargeable battery. When I crank the engine, it loses track of the vehicle it's plugged into. I have to re-enter the VIN data again after it's running.

well long story short the scan tool was being flaky and kept dying out. I didn't even crank the engine over. the scan tool wouldn't stay on or even power up with key on engine off

 

[Schurkey]

OBD-1? Is this an '89?

Scan tool power comes from the cigarette lighter socket. Problems in the socket? Problem in the power cord from cigarette lighter to ALDL connector?