I AM POSTING THIS FOR A FRIEND. Thank You for any help.

ok, background first:
90 DA
96 B20
91 engine harness, distributor, alternator, injectors and ECM

car has worked fine since i rewired the ECM back to stock 2mo ago (was hacked up and running an OBDI ECM). recently at night with the headlights on, the dash would go dim. now it goes dim until i lose the dash altogether and the ignition starts to cut out. i've been through 2 batteries and just replaced the alternator. the alternator will charge the battery when idling. but once you are driving and have the headlights on it does not charge the battery at all and i'm not convinced that the alternator is sufficiently running the car 100%. it is draining more and more quickly over the past week and i can only drive for about 2-3mi before i lose all charge and the car dies.

all fuses are fine and the wiring is SOLID. any ideas?

 

my friend had a problem like that once, there was one wire that came out from the harness and he couldnt figure out where it was supposed to go, chack the harness.

 

Harness is fine. Every wire has been checked.

the problem happens only when the car is driving and the headlights are on