1g rad fans wont turn on

[Sp1kE]

my 1g's rad fans never turned when it hits running temperature or hotter. we went through the repair manual and tested the electrical. and came up to be the rad fan switch. We installed a new switch and still no results. we can turn on the a/c and both fans turn on at warm temperatuires. that is the only time we can get the fans o, other then jumping the switch. what should we test/try next?

thanks Mike

 

[-Stroked-]

I would check to see if it looks like anyone messed with the wiring so they would control when the fans come on...i.e. only when the a/c is on. Some people do that because maybe the relay went bad or it has some wiring problems.

 

[luv2rallye]

If you have stock fans and wiring, your thermo sensor (or it's wiring) on the rad. fan is faulty since the rad. fan turns on with the A/C which means it's relay is good.

 

[Sp1kE]

ok you say the thermo sensor on the rad... the only thing on the rad is the fan switch, is it not? and we put a new one in. the fans still dont turn on. without the ac button.. wheres this buck guy hes the genious. i've been looking at all his fan posts but couldnt find someone have the problem of putting in a new switch and it still not working....
but thanks for the help anyways

mike

 

[luv2rallye]

Sorry I thought you were referring to an external switch which many people use. Yes the thermo sensor is the switch on the radiator fan. Since you replaced it, the problem (according to the DSM Backup Manual CD schematics) has to be either the wiring to that switch is faulty or someone has changed the fan wiring from standard (which is very common on dsm's). I would guess that the wiring has been changed with the thermo switch wiring disconnected (note: grounding the thermo switch should activate the rad. fan relay according to the schematics).

 

[Old Mitsu Tech]

If the fans come on with the ac and do not come on with over temp, it has to be the radiator fan switch or wiring. The switch simply grounds the relay and turns the fans on. Look in that area with a schematic very closely.

Good Luck

 

[slugsgomoo]

get a multi meter, and some test leads. use your test lead to ground the connector where the thermo switch is and see if the fan turns on. Plus, you can check the manual and see what proper resistance should be & whatnot.

 

[Sp1kE]

ok thanks for the help i looked at the schamatic and will check out the car tomorrow.

I did read on another thread to open the rad cap and see if the coolant is moving. then if it isnt then you may need a new water pump..
well we opened the cap and the coolant was like gigling but i think it was just with the engine.... should it be wooshing through the little hole or how should it look?

because it would make sense if the coolant wasnt flowing, then in the rad, the coolant would stay cold and that switch would never be triggered.

thanks again.
mike

 

[Sp1kE]

ok me and my buddy went and warmed the car up to operating temp angain. then we tried the AC button... nothing happened... then he felt the hose comming out of the top of the rad.... it was warm/hot and it appeared that coolant was flowing (we had cap off). he continued and felt the top of the rad.. it was warm.. but then the main part of the rad he felt( the face of it) and it was cold... it stayed cold even after the car began to over heat... weirdest thing is the fans wouldnt turn on even if we hit the ac button.. Then we shut it off. tried to get the fans going just with the key in acces.. nothing.. he started it back up. he hit the ac button and BOTH fans came on........ now were really stumped..

were both thinking ther rad face should not be cold, like no heat at all..??? problem with the flow??
and then the ac fan not comming on the one time but then starting it right back up and hit the ac and both came on...???

sorry to drag this help topic on but maybe this could help someone diagnose our problem quicker...

thanks guys!

mike

 

[Sp1kE]

problem fixed. just thermostat... thanks