Volvo: volvo245 electrical problem, volvo 245, electrical problem

Question
Hi,
I have an '79 Volvo 245 wagon that dies when the lights are turned on. With the lights off the alt. is charging, but when the light are turned on the alt seems not to charge and the engine will die is short order (30 seconds).
I replaced the alt. and during the day it was fine, come night, turn on the lights and if starts to run very poorly. I turned the lights off and it kept running fine.
and suggestions?

Answer
Al,
Test the charging system while the lights are on. If the system is not charging the cluster circuit card, cable ends, wiring harness, alternator, regulator must need some work. Make sure that the cables are good and tight and the grounds good, chassis and engine.