Radiator Thermoswitches - Testing

[psychonaut]

Hi all - please can someone advise if there is a simple way of testing of the two thermoswitches in the radiator are working? Shorting out the contacts operates low and high speed on the fan accordingly, so I'm suspecting duff thermoswitches. Is there a way to test them without borrowing someone elses and running the engine up until the fan kicks in?

Thanks in advance.

[bigherb]

Only by puting it in a pan of boiling water with a multimer set on ohms or a continity tester across the pins. Pins 3 & 2 should switch on at 95 deg C and 3 & 1 at 102 deg C

[psychonaut]

Many thanks indeed. I wondered if there was any other way, but suspected that a pan of boiling water was the only real way to test. I'll break out Mrs. P's best stainless pan in the morning

Thanks again

[Epiphone]

Taking the thermo switches out means all the coolant will come out and then the trouble of bleeding again?

or is there a way of doing this without losing the coolant?

[Oldiebut goodie]

Put a new switch in! Only £12.86 or £18.03 if you need two. Which is cheaper, replace coolant or switches?

[kevtherev]

Taking the thermo switches out means all the coolant will come out and then the trouble of bleeding again?

or is there a way of doing this without losing the coolant?

taper a cork from a bottle... and be quick when you remove it?

[Ian Hulley]

If this is the fan switch then remove the plug, insert a piece of wire into the thicker of the 2 (or more likely 3) wires and then into each of the other terminals in turn, one will be slower than the other (which will probably make you jump ) If the fans come on it's a faulty sensor ... common fault ... this works with the ignition on or off.

If you have to swap the switch have the new one to hand and you'll only lose a tiny bit of coolant as it's flowing through tiny passageways in the radiator matrix.

Ian

[Red Westie]

I changed mine last month (genuine WAHL) you really don't loose much coolant when quick swapping, just make sure you have the switch and new washer ready to go.
My second speed started randomly clicking in and out....like 1-2 seconds then turning off again. I figured given the importance of it working correctly I wouldn't mess about and just changed it,

Martin