Loss electrical power


Asked by Aug 06, 2016 at 05:42 PM about the 1990 Ford F-150 XLT Lariat 4WD LB

Question type: Maintenance & Repair

My 1990 f150 has an electrical issue that I need
help with.  When I turn on the ac it pulls the
electrical power on the amp gauge down to I'd say
less then 10 amps and if I come idle at a traffic
light it goes down even further. If I leave the ac on
and at idle it will drain  the power all the way down
until it shuts off.

2 Answers


It could be your alternator


If it only does it when u turn ac on, u have a short in the system or a bad ac compressor. Disconnect the olug at the ac compressor and turn ac on, if it still does it, u have a shor in the ac circuit but if it doesn't do it, replace ac compressor

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