MY Thermoswitch replacement

Cliff R · Post by **Cliff R** » Sat Apr 26, 2014 10:10 am

I couldn't get the MY's thermofan to come on even with the engine temp up at 3/4's plus on the gauge,
In fact the car was on the way to boiling and the radiator overflow bottle was actually boiling over.
I decided to locate a new thermoswitch and did so via our local Autopro shop.
The new switch is a Tridon brand with a part number of TFS195.
This switch has been discussed on the forum in the past but in my case, with the new switch fitted, both the main and the A/C fan now come on just under the 1/2 mark on the temp gauge and while I haven't been able to drive the car as of yet (fuel pump dodgy) with the car idling the fans bring the temp back down to a very low level with the fans still running.
I don't know at what temp the fans will cut out as of yet but the fans certainly cut in at a good engine temp level.
Note - Autopro in my case were the cheapest for the same thing out of Supercheap and REPCO (locally anyway)

YouTube · Post by **El_Freddo** » Sat Apr 26, 2014 11:35 am

That's good that you found it before serious damage occurred.

I'm also glad to know that my brumby's fans kick in at the same time as yours - I was a bit dubious about that...

Cheers

Bennie

Cliff R · Post by **Cliff R** » Sat Apr 26, 2014 1:18 pm

Just a question about the MY fans.
Does the A/C fan come on when the A/C button is pushed and if so is this dependant on if the A/C system is fully charged.
My A/C is out of gas so the compressor does not kick in (fail safe) but from memory the A/C fan still used to come on when the button was pushed.
I now notice that the A/C fan does not come on when the A/C button is pushed but does come on with the main fan when the thermoswitch activates.
Maybe I remember wrong but I was sure regardless of the compressor coming on or not the A/C thermofan always came on when the A/C switch was pushed.
Anyone got any thoughts regarding the factory fitted MY A/C system, their thermofans and when they come on ?
Maybe there is a relay that controls the A/C fan ?

Post by **Bantum** » Sat Apr 26, 2014 1:57 pm

Yep a relay controls the fan ... ( relay is located on top of strut tower - left side as you look into engine bay - in a MY anyways ) I'm not sure about the thermo switch though, I think it's also linked ... there is a wiring diagram somewhere ...

Add : Found it :

So the fan should come on when aircon is turn on ( but only if in temp range ) - check the relays as contact points can stick / wear.

Note : there's a spring in there somewhere too - which can lose its effectiveness ...

Cheers, Bantum ...

steptoe · Post by **steptoe** » Sat Apr 26, 2014 6:11 pm

search th forum for TFS132 or TFS134 I got one or the other, yet to test it out to see if it is working

Cliff R · Post by **Cliff R** » Sat Apr 26, 2014 9:24 pm

Ta, I will look into this when time permits.
Just need to sort the fuel pump issue so I can drive the car

RSR 555 · Post by **RSR 555** » Mon Apr 28, 2014 12:09 pm

I'm 99% sure only the A/C fan (skinny black one) comes on with the A/C and the other one (I think it's on the drivers side) only comes on via the thermo switch. I have mine wired up so I can override the thermo switch, so I can turn it on earlier when I'm on the beach or travelling with the wind.

Cliff R · Post by **Cliff R** » Mon Apr 28, 2014 6:27 pm

Bugger, removed the two relays located closest to the engine and popped off the relay covers. All looked ok with no marks etc. (didn't pull the third relay closest to the guard)
Picked up three relays from the wreckers and fitted all three but still no good.
Will look into wiring when I can.

scott64 · Post by **scott64** » Tue Apr 29, 2014 9:55 am

Hi guys no answers sorry just a similar problem. 99 forester ej20,both thermo fans work only with aircon. sub fan wont come on as it should have checked both relays and are fine, have wired in a switched earth to sub fan relay so i can switch it on and off for town driving. do you know where the sensor is that triggers the sub fan? have changed the sensor that controls the dash gauge. would like to do away my switched earth, well maybe keep it but want fan to work correctly.

RSR 555 · Post by **RSR 555** » Tue Apr 29, 2014 4:14 pm

scott64 wrote:Hi guys no answers sorry just a similar problem. 99 forester ej20,both thermo fans work only with aircon. sub fan wont come on as it should have checked both relays and are fine, have wired in a switched earth to sub fan relay so i can switch it on and off for town driving. do you know where the sensor is that triggers the sub fan? have changed the sensor that controls the dash gauge. would like to do away my switched earth, well maybe keep it but want fan to work correctly.

Next to the Temp Sender Unit that you replaced, should be the Coolant Temp Sensor. It's a 2 pin unit that sends a signal to the ECU and the ECU will trigger the Fan Relay. From memory you should be able to check the resistance of the Coolant Temp Sensor with a multimeter. Not sure what the resistance should be but if you grab a copy on the WorkShop Manual (see link in my signature) for your model and you should see it in there.

YouTube · Post by **El_Freddo** » Sat May 03, 2014 11:33 am

The second fan will only operate with the AC on OR when the radiator thermo switch is activated.

I would have a guess that the AC button will only activate the secondary fan when the AC compressor is engaged - at which point it operates both fans. But if you're out of gas the compressor will not be engaged thus the fan will not operate in this fashion.

Also check the fuse from the battery to the AC system - if this is blown or missing the second fan will not operate at all.

Hope that makes some sense!

Cheers

Bennie

Cliff R · Post by **Cliff R** » Sun May 04, 2014 2:32 pm

Thanks for the suggestions Bennie.
Other things will take priority for now, like -
Change rear wheel bearings, seals, brake shoes and slave cylinders.
Change front brake line flex hosing
Sort out indicator not cancelling out on turning to one side.
Will get there in the end but with the car due for rego in 4 weeks I will have to push things along.

YouTube · Post by **El_Freddo** » Sat May 10, 2014 6:18 pm

Cliff R wrote:Other things will take priority for now, like -
Change rear wheel bearings, seals, brake shoes and slave cylinders.
Change front brake line flex hosing
Sort out indicator not cancelling out on turning to one side.
Will get there in the end but with the car due for rego in 4 weeks I will have to push things along.

Sounds like a good weekend's work if you know what you're doing. I'd be working on the rear drive shafts first if you've never had them off - they'll be welded on due to rust. Once you've got the pins removed a slide hammer with a reinforced hook piece does the trick well (did this about 6 weeks ago on Redback!)

Cheers

Bennie

Cliff R · Post by **Cliff R** » Sat May 10, 2014 9:16 pm

Changed the rear bearings (and outer sleeves), brake slave cylinders and brake shoes. Also changed the front brake flex lines.
Have new favourite tools now (a must for this job to make things easier)
-Hydraulic press (and various spacers)
-electric impactors (cordless and 240v)
-correct home made tool to remove and install rear bearing hub retaining ring
-10mm flare spanner (undoing brake lines)
Haven't test driven it yet, still getting the air out of the brake system.