Advise on 3 pin cooling fan sensor wiring.

[opticaltrigger 52]

Hi Guy's, working on the project car again, and I need to ask if someone could tell me what the pin outs are on the 3 pin fan sensor switch in the radiator.

I have the wires that go to it but there's no plug anymore so I need to know which pole is the supply and which two are for the fast and slow outputs.

Also guy's out of interest, how much current are these sensor switches good for, if anyone knows. The last one gave up and the plug was fried on the end of it.

Any help with the pin out would be very much appreciated.

 

All the very best guy's

O.T.

 

Edited December 3, 2018 by opticaltrigger

[welshpug 1,661]

I would try and find a loom from a zx or a 405 single fan two speed, they use a relay  so the full fan current is nor drawn through the thermoswitch, far more reliable than the arrangement the 205 uses.

 

I've attached a picture of the diagram shown in the haynes manual for the 405 single fan loom.

 

looks like pin 1 is input and 2 is high speed via the relay, pin 3 is through the resistor.

[Ryan 99]

The fan has a 25 amp fuse from memory, so the switch must be rated for something like that. They're pretty beefy switches, but obviously they're not going to last forever. Normally they burn out from age or from people trying to run twin fans through a single switch.

[Tom Fenton 1,542]

They are s*ite these days

OK I've a few 205's to go at but have replaced numerous on my own cars over the last few years. Changed 2 switches and then had to do both again 12 months later. Garbage.

What I've done as a trial on one of them is set it up with 2x relays to take the load off the switch to see if that makes them last

 

[opticaltrigger 52]

Mei, Ryan, Tom,

Many, many thanks for the replies guy's. That helps loads, sounds like a relay is the order of the day here.

Just to be a complete pain and push my luck a little further here gents. Has anyone got a picture of the pins on the switch which shows which ones are number 1, 2, and 3, as I literally only have 3 wires (supply, fast, & slow.) and 3 pins on the switch to work with at the moment.

 

All the very best Guy's and many thanks,

O.T. 

 

Edited December 4, 2018 by opticaltrigger

[Rob_the_Sparky 9]

FYI: Not quite what you are asking but the 205 diesel runs the same type of thermo-switch but with a twin fan and relay set-up from factory.

[welshpug 1,661]

the plug is numbered

 

http://www.farnell.com/datasheets/2080928.pdf

[opticaltrigger 52]

Thanks everybody,

Very helpful of you guy's.

 

Many thanks and all the best,

O.T.