When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
98 expedition w/ 4 wheel LLS. compressor recently started to not turn off randomly, like every second or third time i drive it. the compressor comes on when you start it up and drive like usual, but does not turn off while driving (mostly...), and even after the vehicle is stopped and key out of the ignition, the compressor is still running, for minutes and minutes straight. drained the battery once, until i figured out some vodoo combination of starting the truck a couple times and turning it off, turning the ignition on and off several times without fully starting up is the only way i can get the compressor to stop. LLS on/off switch being turned on or off has no effect.
that was weird. the compressor wouldn't turn off, was raising the front to as high as it would go.. fixed itself, the only thing i did was unplug the battery for a few hours. hooked the battery back up, so far so good. still no leaks, checked the usual suspects.. knock on wood.
It sounds like a computer type of issue in the module. If I were you I would start looking for a known good used module just in case it happens again and won't reset. If there's a Pick-N-Pull type of yard in your area, that is where I would start looking as the module would only be a few bucks there and who knows anywhere else.