mofologic

newest antics of the old girl - when at idle and the heater motor blowing, the tach bounces from idle to 2-3k, but the motor is still at idle speed. when i turn the blower off, it acts normal. when i rev the engine/accelerate, the tach works fine. any ideas or is it demon possession?
joseph

ravidrabbit

Ground wire in your climate control loop somewhere.
Check your plenum and your programmer.