Woody21 Posted July 11, 2012 Share Posted July 11, 2012 Hey guys and gals, it's my first post on this forum and I appreciate any help that anyone can offer. My 1995 Subaru Legacy is having an issue with it's cooling fans. The main fan (Driver side if I am not mistaken) seems to be operated by the sub fan circuit. When I turn on the AC the main fan kicks on. The sub fan sits dead all the time. I tested all the relays and they are good. The grounds look good. I checked the fan fuses and they are good. I checked the fan motors by hooking them up to a battery and they both spin just fine. My car isn't throwing a code for the coolant temperature sensor. I'm at my wit's end right now with what could be wrong. Any help in getting this problem fixed is very appreciated. It sucks driving around with the heater on and windows down in summer. It only overheats in city driving with the AC on. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted July 11, 2012 Share Posted July 11, 2012 The main fan is suppose to turn on, and stay continually on, when the A/C is in operation. The sub fan does not necessarily turn on, just because the engine is running. It is thermostatically controlled, and will only turn on when motor is getting hot above normal operating temperature. Driving the car pushes enough air through the radiator, so fan does not come on. Only if you are stuck in stop and go traffic on a hot day, will the sub fan come on. So, I am thinking there is not anything wrong with your cooling fans. Keep an eye on your dash board temperature gauge. If engine is started from cold, and needle stays in the middle of the gauge after warm up, and never goes up towards HOT, then you aren't having a problem. Quote Link to comment Share on other sites More sharing options...
Woody21 Posted July 11, 2012 Author Share Posted July 11, 2012 Alright I'll re-explain. The passenger side fan in not operational and it does overheat going uphilll with the AC on. Quote Link to comment Share on other sites More sharing options...
Wayback Posted July 11, 2012 Share Posted July 11, 2012 (edited) The fans are two speed. Both fans turn together, at the same speed, low or high. If one fan is turning and one isn't, something is wrong with the one that isn't turning, or the circuit controlling it. Note that there are two circuits for each fan. Each fan has 3 or 4 wires, one or two ground and two power. If one circuit is energized, that's low speed, both energized, high speed. Edited July 11, 2012 by Wayback correct number of fan wires Quote Link to comment Share on other sites More sharing options...
Ricearu Posted July 12, 2012 Share Posted July 12, 2012 if you plug in both sets of test connectors (green and black pairs) under the dash, the ecu should cycle both fans with the key in the run position. on. off. on. off. Quote Link to comment Share on other sites More sharing options...
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