A couple more questions here about my friends 90 supra gte swapped 7m.

1)The car idles around 600 but when you turn on the headlights...the car immediately jumps up to around 850-900...vise versa when you turn them off.
2)The cluster lights don't work. He said they used to but is not sure why they don't know. Fuses are good. He thinks it may be some sort of dimmer switch that has gone bad? We haven't tested anything with a voltmeter yet; just thought we would try asking around first.
3)When the car is cold, it randomly turns off. It will immediately turn back on. He thinks it's normal...I concure! Sounds alternator related to me...along with the weird idling.

Thanks.

Bump!

Still would like to know!

I agree with you this is a weird one. Double check all of your grounds. Then diagnose the alt.

Sounds like something is shorted out. Maybe you have a wire that is grounded that shouldn't be, or didn't get hooked up right. This is just sort of what happens when you try to splice things togeather.