My aux. fan seems to run constantly. I pulled the plug on it after a 1/2 hr being parked and engine off. How long can it possibly run? Isn't there a timer of some sort? I see there's a relay. If the relay is OK, what controls it, the thermostat?
tia, Mel P.
Switch in physical contact with the radiator, possibly screwed into the bottom tank. I'm thinking you may have to drain the coolant to replace it. There is no doubt a relay too. This fan runs with the engine off, to prevent boiling of coolant and objectionable noise after the engine is shut off. Half hour is definitely too long, you have a switch or relay problem. I would tell you more, but I no longer have the Cherokee book.
Cheers,
Earle
** Posted from** Posted from
According to this there should be a code, but PCMs aren't always that smart. I am thinking relay bad, somehow not throwing a code. No way it could stay at 190° for a half hour without the engine running, unless he's calling from Saudi Arabia or Death Valley on a hot day. Bad physics. Remote possibility, bad PCM.
Earle
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The fan power comes through a relay and those can stick (welded contacts). Locate the relay and swap it with one of the others - the fuel pump relay is a good choice - and see if the problem goes away.
................. not unlike Plink Fraud
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