Some background:
82 GS, 92k miles bone stock.
sparkplugs, fuel filter was changed 6 months ago. carb was cleaned out in July because of a clogged jet.
car starts strong most of the time but sometimes needs a 2nd try.

The story is a little long because I'm not sure if the symptoms are related. I tried searching, but the terms would be a little broad.

Friday 11/11
drove not too long. Turned on air conditioner at a red light, Exhaust Overheat light came on. Turened off AC, and the light went out instantly. I figured a short somewhere.
Turned AC on again briefly later that day, nothing happened.

Saturday- the real problem
Did a little driving around town. Stopped for over a half hour, then went on driving down a highway for over 20 minutes, turned on AC, then about a few minutes later the car starts bucking a bit. I was in 5th gear at 65mph, a little over 3k rpm. I pulled over, slowed down, turned off AC. I didn't switch off the engine, and decided to experiment a little, so I go back on the highway back up to around the same speed, so far okay. Turned on the AC, the car started bucking again. Switched off AC, but the car kept shaking and I started losing power. rpms kept going down, so I pull over and switch off the motor for maybe 5-10 minutes. Stayed off the highway on the way home, no issues.

At night I took the car out again, left the AC off. Did some city driving, some highway driving, revved it to almost redline when I was on the highway. No issues, didn't turn on the AC though.

Sunday
I went to a buddy in the local RX club to help diagnose the problem. We went in the car down a highway, got up to speed a little over 65mph in 4th then 5th gear, turned on AC. did this for a little over 20 minutes with no problems.
Then he started playing with the map/swivel light- it wouldn't work, the chime that goes off when the door is ajar came on, but a little quieter. The dome light wouldn't work either. The headlights worked, however. In a couple of minutes, they started working again with no issues.
The car behaved the rest of the day, and today.

My friend looked at the wiring diagram I got off iluvmyrx7.com and guessed it was probably a bad ground or the CPU screwing up or some worn wires getting crossed. And somehow that might have messed around with the ECU to cause the loss of power by messing with a valve or vacuum.
I don't know if this is related or not, but the dome light sometimes flickers when the door is wide open. And the I've had no problems with the CD player.

Am I on the right track as far as the CPU being wacky or a bad ground? I'm sure the AC has definitely got something to do with it.

Thanks.

 

anybody??

point me to an old thread, anything

 

dude.. check all the major rust points near electrical harnesses, and of course, fuses and fusable links (though thats unlikely)

your friend is right about the bad ground.. the interactions between components there are too bizzarre to dream of, so go rust huntin.