playa69

anybody know anything about geo prizms? our geo's fan isn't turning off. the engine is cool, the A/C is off, but the fan runs. we've changed the cooling fan sensor and the cooling fan switch. but it keeps running. any one have any idea?

smash

Are the cooling fan sensor wires shorted to ground or together? does it continue to run when the engine is off? is your blower motor conrol set to defost? that will cycle the a/c compressor causing the cooling fan to temporarily come on. did you try the cooling fan relay? it could be shorted out internally or the wiring to it. the only other thing that comes to mind would be a faulty PCMor a false input to yhe PCM. I would start with the cooling fan relay since it is easy and inexpensive part to replace.&nbs p; </P>


Smash</P>

playa69

dude, u r so right. it was the pcm, my guess is that it was either the cooling fan sensor, or the switch, my dadrevved (to heat it up)the motor until the pcm got a new reading.......we could have just reset the pcm by unhooking the battery! thanks bro!</P><edited><editID>playa69</editID><editDate>38598.6821064815</editDate></edited>

smash

no problem bro!

Patrick

thanks for the help there smash!!

playa69

crap! it's happenin again! i'm guessing getting a cooling fan switch from a junkyard was a bad idea. or maybe that's not it?

smash

I would go through what i said earlier and if you diagnose it as a cooling fan switch i would by new.</P>


Smash</P>

playa69

it was the switch, i think, i hope it doesn't happen again

playa69

damn, it's running no stop again, it's not the switch the sensor, or the relay( cuz i changed that too) what could it be!!

playa69

now the idle is screwed up. it drops a couple hundred rpms then goes back up, especially when i remove the relay for the fan (to turn it off) it gets crazy.