9 replies to this topic

[Sweet82]

My 01 Forester seems to be having cooling problems. I first noticed it when I was towing a light load up a canyon.

Next I noticed it in the city with the A/C on?

The heat gauge goes up to the 3/4 mark or higher. Then I turn off the A/C and do what I can to cool the car off.

Why is this happening?

Someone suggested that one of my fans (AC) may not be kicking in when it should?

I noticed my r/h/s fan goes on when it gets hot. I have not seen the l/h/s fan on. Is the l/h/s fan suppose to come on with the AC?

Any thoughts?

Glenn,
82 SubaruHummer
01 Forester

[nickb21]

FWIW.. I would assume the cooling is pretty similiar between the legacy and the forester. Bot the left and right side fans in my '00 legacy go on when it gets hot and when the A/C is enganged.

You might want to check out the fuses/relays in the main fuse box, I seem to recall there being 2 fuses and 2 relays that are listed as "fans".

Hope that helps some..

[MailManX]

Both fans should come on when the A/C is turned on no matter how warm or cool the engine is. So if the A/C is on, but one fan isn't, it explains your cooling problem. I hope for your sake it's just a fuse 'cuz Subaru charges a freakin' forturne for their fans. I had to order one for my Legacy a few months ago and the retail on it was $216. I ended up ordering by phone from Lithia Subaru in Oregon because they were willing to charge me a lot less, and the lack of tax covered the cost of shipping.

[Mark-O-Back]

Here's how my '97 fans work.
One of the two fans will come on with the A/C no matter what the coolent temp. (I think it's the right side, passenger. EZ to check)
The other one comes on when the coolent gets hot enough. So to get both fans on takes hot coolent and the A/C. (this is in my owners manual too I think)
So it sounds like the problem could stem from a non-functional thermostat or relay. (not the thermostat that opens to let coolent into the radiator, the one that closes an electrical switch to enable a relay to run the other fan)
Heck if your lucky it could be a loose wire.

Maybe the '01 is different, but don't blow $200 + until you consider this information. :-\

Good luck,
Mark

[ferret]

Here's how the Forester lays out (bear with me, the manual does NOT state which is the main fan and which is the sub fan by position under the hood. I would assume from the diagrams that the Main fan is the one turned on by the engine temp, and the sub fan is the one turned on by the A/C.

Either way, the circuits are IDENTICAL with swappable parts. Both fans are the same with the same connector so they can be swapped.
Both relays are the same so they can be swapped (under hood in Power Dist Unit (black plastic box mounted along drivers fender behind battery). Relays are marked Main Fan and Sub Fan.
Fuses to supply power to fan motors can be swapped. Both are also in the same Power Dist Unit under the hood.
Both relays are turned on (grounded) by ECU....that could also be the problem.
One last item on the Forester....Each fan relay has a seperate power feed.....Main fan relay is powered by fuse #18....Sub fan relay is powered by fuse#17. These are both in the fuse box in the passenger compartment behind the little storage tray just to the left of the driver. Look where your knee would be, open the tray then lift it up to remove it. It reveals the interior fuse box and fuses #17 and 18.
Good hunting..If you need the schematic for the Radiator Fan System, please let me know, I will email you them in PDF form.

[Sweet82]

Thanks for the help, I think I have tried everything suggested....

I swapped the relays under the hood and no matter which relay (sub fan and main fan) the right side fan came on--with the A/C. So this tells me the relays are both good.

I checked all the fuses under the dash and under the hood. So I know it's not the fuses.

I jumped 12 volts to the left fan and it came on!

At this point I'm suspecting a control thermostat????

Note: someone before me swapped out the Left harness fan connector for something different and zip tied the connectors together because the new connector would not lock onto the fan connector? However it still seems to be connected?

Any thoughts? Now there is cooler weather it's not acting up, but I'd still like to fix this problem.

Thanks,
Glenn
82 SubaruHummer
01 Forester:(

[Sweet82]

Bump! Any Help?

[coloradosubarules]

Simple fix. Go to your nearest parts store and get a 12 volt heavy duty relay. Go online and get the wiring diagram of a relay and study it. Once you feel confident that you k now what goes where, wire up the relay so that the second fan comes on when the first fan comes on. Problem solved.


1. Relay has 5 terminals
1. Const power
2. switched power (from POS side of working fan)
3. Ground (duh)
4. Directly across from #1 is power to your POS side of non-working fan
5. This terminal is not used. (the one in the middle if the two that run parallel to each other.) You will see what I mean.

Use a good sized wire (nothing too heavy) and the proper connectors. Wouldn't hurt to cover the terminals in silicone once you are sure the set-up is working. (Mount relay to safe place away from heat or moisture, wouldn't hurt to cover entire relay in silicone)

Hope this helps

[Sweet82]

Thanks!

I have a relay that I bought but didn't use for the Buggy headlights. That might work.

I wana find the sensor that should be activating the problem fan and look at that first.

Question: Any ideas on what might have malfunctioned (sensor?) that I can look at first?

Hints on where its located might help too.

Thanks for your help.
Glenn
82 SubaruHummer
01 Forester gonna get fixed one way or the other!

[MorganM]

Thanks!

I have a relay that I bought but didn't use for the Buggy headlights. That might work.

I wana find the sensor that should be activating the problem fan and look at that first.

Question: Any ideas on what might have malfunctioned (sensor?) that I can look at first?

Hints on where its located might help too.

Thanks for your help.
Glenn
82 SubaruHummer
01 Forester gonna get fixed one way or the other!

Just talked to a couple Subaru techs at local dealerships. The thermosensor is on the coolant corssover pipe on the passangers side. There are 2 sensors, one for ECU and one is for fans. The smaller one is for the fans.

Now 2 people said the default action if that fails is to run the fans all the time. This is how it was on my '91 Legacy also. One person said no it would just shut them off and another said 'no comment' =P

A sticky thermostat could be to blame. They tend to get stuck SHUT and not open all the way and some times not at all Also any air in the system? That can cuase spikes in your temp. I've had pin hole leaks in hoses that cuased temp spikes also. Check all them hoses good for tiny holes and give them a good squeeze to see if they are still solid or all worn out.