83 22re runs rough under electrical load

[tonycg]

car runs and idles good until I turn on lights or fan rpm jump up about 500 to 700 above normal much worst with both on 1000 1500 and fluctuates. engine runs rough the higher the rpm the rougher

[DeltaP]

Any accident damage on car? Check for shorted wiring. Check alternator output then fully charge the battery and load test it.