None of the parts stores here can find i, even the ford dealer has no clue. It's the relay on the pass. side fender well w/ four wires going to it. It shuts the A/C compressor off when you are WOT. Mine kicks it off but won't let it come back on I have to disconnect it for it to send power back to the compressor clutch. The parts guys are saying there is also another name for it, but noone knows what though. The part# on mine is worn off. Thanks for any help.