On my subaru the cooling fan does not come on. When I first got the
car it seemed the fan was always on. Then sporadically would come on.
Should I buy a cooling fan or a switch...
Hi,
Being possessed of a genetic predisposition to being a cheapskate,
sometimes I've found I have happier DNA when I've troubleshot things
sufficiently BEFORE rushing off to part w/ my money.
So, have you checked the individual components?
The fan may be burned out. Disconnect it from the factory harness and
hook it up to a known power source (battery) and a known good ground. It
should run. If not, you know where to start! I found a good one for my
car at the junkyard.
If your car's wired like mine, I believe you have power coming from the
harness to the fan motor, and ground is completed thru the thermoswitch
mounted in the radiator. W/ the harness unplugged, check it for voltage,
and check the thermoswitch for a closed circuit when it's hot enough.
Depending on the switch operating temp and the temps you can achieve
idling, you may be able to do this "on the car" but depending on
circumstances, you may not be able to get it hot enough, and it'll have
to be removed from the radiator and tested in boiling water. Suggest a
new one from Subaru if yours is bad.
If your car has A/C, there may be an auxiliary circuit to activate the
fan, regardless of coolant temps, whenever the A/C compressor's engaged.
You'll probably want to spend a few bucks and get a manual to show your
wiring for the specific car. Check all the associated connections.
If all that checks out, polish as many of the contacts as you can reach
w/ some fine sandpaper or steel wool (or even scratch 'em clean w/ a
small blade), put some dielectric grease in any connectors you've
disconnected, and plug everything back together to see if it's just a
corrosion problem. Also, trace the ground from the thermoswitch and see
if it's good wherever it connects to the chassis.
There are possibly other problem areas related to ECU contacts, other
coolant sensors, etc., but I'd start as close to the problem as I could,
then work back into the depths...
Rick