Remote cooling fan ''switch"?

[dave egan]

Hey , guys, I think this is a ''common enhancement''? I was wanting to retrofit a ''manual switch'' to accompany the ''automatic-thermostatically-controlled" front-oil-cooler , electric cooling fan, on a late 80's 930 coupe. Does anyone know of the simplest way to wire up a manual switch , enabling the driver to turn on the cooling fan at will , and thus preserving the function of the OEM cooling fan activation? thanks;dave

[Bart_dood]

I think you basically wire in a switch that manually operates the fan relay, if you have a bentley's manual have a look in the schematic section.

I would like to know where I can get a lower temp thermostat switch for the oil cooler fan.
I checked pelican and they only seem to sell the stock 110c switch and nothing lower, anyone know where to get one?

thanks!

[JessL]

Dave,
Easy to do. The thermostatic switch that turns on the fan simply completes the circuit to ground. Trace the wire back from the switch to the fuse panel. On my '89 the wire is grey and runs under the front lip of the trunk. Connect into this wire and run a new wire back inside the car.
I placed my switch next to the headlight switch( I bought the car with a dead clifford alarm, which had a signal light next to the head light switch, I used that hole.) Wire your new switch with one leg to the new wire and one leg to ground.
I turn the fan on all the time in hot weather and always when the a/c is on, sorta' a pre-emptive strike.
Now I never see temps higher than 220F even in stop and go SoCal traffic. Originally, I would see 250F even with the Pelican air scoop in the bumper.
Cheers,
Jess

[boyt911sc]

Originally Posted by dave egan

Hey , guys, I think this is a ''common enhancement''? I was wanting to retrofit a ''manual switch'' to accompany the ''automatic-thermostatically-controlled" front-oil-cooler , electric cooling fan, on a late 80's 930 coupe. Does anyone know of the simplest way to wire up a manual switch , enabling the driver to turn on the cooling fan at will , and thus preserving the function of the OEM cooling fan activation? thanks;dave

Dave,

I've done this when I installed a Carrera cooler in my '78SC some years ago. I'm assuming that you have a relay in your set-up. The cooler fan is energized when the thermoswitch makes ground contact. To manually run the fan, you need to over-ride thermo switch. Connect a wire to one of the prong (terminal) that is not grounded in the thermoswitch and connect a switch. You could even add an indicator light that lit up everytime the fan is ON.

In summary: Install a ground switch for the electric motor (fan) via the thermoswitch.

Tony

[dave egan]

Got it , Thanks , Fellas! "thermoswitch" location? ., back side of engine perhaps with temp. senders etc., or some place else?

[Bart_dood]

So does anyone know where to buy a lower temp thermostat?

[boyt911sc]

Originally Posted by Bart_dood

So does anyone know where to buy a lower temp thermostat?

I got my 196°F/91°C BMW auxiliary fan switch (2-prong) from Pelican a long time ago. This is a common thermoswitch among European vehicles and probably Japanese cars too. The bag describes it as BMW 318i ('84-'85), 325 i/iS/iC (from 8/87) or M3 (from 02/87). HTH.

Tony

[boyt911sc]

Originally Posted by dave egan

Got it , Thanks , Fellas! "thermoswitch" location? ., back side of engine perhaps with temp. senders etc., or some place else?

Dave,

The thermostat switch or thermoswitch for the Carrera cooler is located on top of the cooler/radiator. It is not easy to locate because it is well hidden under the right front fender. Or you could connect another wire from the electric fan motor (negative or ground side) with the switch. This will be the same as tapping at the thermoswitch.

The one on the left side of the engine is TTS (thermotime switch). Which is completely different from what we are discussing. HTH.

Tony

[mthomas58]

Originally Posted by dave egan

Hey , guys, I think this is a ''common enhancement''? I was wanting to retrofit a ''manual switch'' to accompany the ''automatic-thermostatically-controlled" front-oil-cooler , electric cooling fan, on a late 80's 930 coupe. Does anyone know of the simplest way to wire up a manual switch , enabling the driver to turn on the cooling fan at will , and thus preserving the function of the OEM cooling fan activation? thanks;dave

Did mine. Details here:
Yet another cooling fan question

LED is on when fan is off?

[fintstone]

Couple of other good threads on the task:

Thermoswitch for Oil Cooler Fan

oil cooler fan thermoswitch

[ianc]

oil cooler fan t'stat and switch installation

ianc

[Barrpete]

Originally Posted by Bart_dood

So does anyone know where to buy a lower temp thermostat?

Elephant Racing sells an aftermarket thermostat that is adjustable down to about 170 F, IIRC.

It would not replace the existing temperature probe/thermostat, rather It has a probe that fits into the oil cooler fins, so you would just have to bypass the existing thermostat and splice the new one in.