very unusual cooling fan issue 92 sl1

[macexperts]

i have been trying to diagnose this but to no avail


a month ago i noticed the cooling fan wasn't coming on
having had several fail i replaced the motor and it wouldn't come on still

checked/swapped relays, all fuses are good

eventually pulled motor and wiring harness

put multimeter on two clamps on harness, start car, i get 13.4~14volts
amps are 2.26 (a/c is engaged to get fan circuit on)

presuming motor might be having an issue i replaced it with new
and still i get nothing

i ran a ground line from one pin on the relay, i can ground the wire and hear the relay engage but no still no fan


if i'm getting nearly 14v at harness
does anyone know if 2.26A is enough? seems like it should be to met




i am really perplexed here, i mean i am getting volts so the circuit completes

ECTS was changed (but its a non issue cause a/c on should mandate fan on, also jumped pin a to pin b on computer connector which also mandates fan on to no avail)

one guy on another forum mentioned grounding issues
but if i can get volts readings i presume have a good return ground on the wire but i can be wrong

all help needed/appreciated tia

[saturnspeed_12]

wow, i would have to say probably a ground issue but wouldnt say for sure.

but you do know with obd 1, they have 2 sensors. one for pcm and another for the fan. if the connectors are not replaced along with the sensors it can retain same issue because with most the stock plastic sensor cracks and lets coolant pass through it to the connector and the connector corrodes and continues down the wire.

also have you just tried to hot wire the fan? i cant remember what size wire to use like 10 i think and put a 40 amp fuse inline with the hot wire, ground the other terminal and see if the fan works. car doesnt need to run for that. its just process of elimination. i guess you did check for voltage to the fan.

also the motor should pull quite a few amps. i dont fully get were the 2.26 amps are coming from

[macexperts]

the fan motor is known good, can run direct from battery etc.


the 2.26A is a readout on multitester @ the fan wiring harness (i.e. the wire going to the fan is 2.26A and almost 14volts)





the connectors on the ECTS are good

but those are irrelevent since I get a reading at fan harness for 14volts/2.26amps when i turn on the A/C (which forces Fan ON)

[peppermrj]

Does the AC engage. The AC on my 96 has a leak. With no refrigerant charge the AC compressor will not engage and neither will the cooling fan. The cooling fan does engage when the temp gauge reads over the halfway point. It takes a while to get there at idle even on a warm day.

[macexperts]

Originally Posted by peppermrj

Does the AC engage. The AC on my 96 has a leak. With no refrigerant charge the AC compressor will not engage and neither will the cooling fan. The cooling fan does engage when the temp gauge reads over the halfway point. It takes a while to get there at idle even on a warm day.

yes the AC engages

just to clarify, i am 100% confident the circuit to engage is functional
because as i posted before i even jumpered the relay circuit to "force" the fan on

also when i put in the AC button the voltmeter goes from 0v to almost 14v as it should, which indicates the engagement circuit/relays are doing what they should (at least as AC engaged goes). also AC clutch engages and runs for a few minutes but when its hot the cpu disengages AC so it won't overheat




thanks, hope someone can help

i am guessing that 2.26Amps isn't enough juice for these fan motors
BUT how can i be getting power there reduced??(at the wiring harness for fan)?

can the wires be acting as a resistor weakening the ouput? but why full voltage of 13.5~14v?? if that is the case?

[peppermrj]

From what I know if there was resistance in the wiring you would get a voltage drop. I'm with the ground theory. Provide an alternate ground.

[peppermrj]

Be sure to use the same size and legnth of wire.

[macexperts]

Originally Posted by peppermrj

Be sure to use the same size and legnth of wire.

iEXTRA GROUND DID NOTHING FOR ME
ran from housing of fan motor to frame




hooked up voltmeter, started car, engaged A/C, volts went from Zero to 14.10V

which indicates controller circuit is working and putting out 14volts
turned off ac switch
volts remained at 14 for 2~3 minutes approximately
then went to zero

i just don't get it

i presume the fan motor is multiuse and isn't correct application for this car but direct to battery fan works, very odd ..and its new to boot....

but i have used this motor before and in another saturn

[saturnspeed_12]

man im kind of lost. what is pulling the 2.26 amps thats in the wires for the fan? the motor would show amps in the wire once its working. it sounds like something else is messed up in the wires. i will go an check mine here sometime and see what i find but i removed my a/c so i have to wait till mine warms up. something just doesnt seem right.

[macexperts]

Originally Posted by saturnspeed_12

man im kind of lost. what is pulling the 2.26 amps thats in the wires for the fan? the motor would show amps in the wire once its working. it sounds like something else is messed up in the wires. i will go an check mine here sometime and see what i find but i removed my a/c so i have to wait till mine warms up. something just doesnt seem right.

yeah i dunno where that 2.26 was from , probably the relay cause the motor wasn't in series then

you can force the pcm to turn on your fan by grounding a pin in the relay for the cooling fan, its the left most pin facing the car, move it to ground that engages the relay and the fan comes on in which case you could get a reading

i assume the fan pulls alot since it has a 30ampfuse on it


thanks for everything
, i pulled the grounds near the fusebox and i'm cleaning them

i'll let you know if it does any good ..i know for sure i am getting 14 volts at the harness-but fan won't turn
so weird