How to Test Cooling Fan relay - Page 2

SD1too · 27th March 2020, 08:01

Fred,

Whilst you're sitting at home waiting for a call to go to work, perform the "demist test" (with the engine running).

If the fan doesn't run, it's a faulty resistor.
If the fan does run, you have an overheating problem.

Simon

planenut · 27th March 2020, 08:03

Quote:

Originally Posted by SD1too

Fred,

Whilst you're sitting at home waiting for a call to go to work, perform the "demist test" (with the engine running).

If the fan doesn't run, it's a faulty resistor.
If the fan does run, you have an overheating problem.

Simon

Thanks Simon, did the "demist test" yesterday, seemed to run fine. Like I said, a run will give me some more knowledge of where I am. As you realize, if we don't do these things for a while, the awareness of what we are looking for fades.

SD1too · 27th March 2020, 09:37

Quote:

Originally Posted by planenut

Thanks Simon, did the "demist test" yesterday, seemed to run fine.

Thanks for confirming Fred. I see no evidence of a fault with your fan system. The fast speed suggests overheating though so when you go out for a drive can you activate the instrument pack diagnostics to monitor the running temperature. It should be somewhere in the low to mid nineties. When you get home, leave the engine running for a few minutes whilst still watching the temperature. It shouldn't rise above 104 degrees and decrease when the fan starts running.

Simon

27th March 2020, 08:01	#11
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,344 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Fred, Whilst you're sitting at home waiting for a call to go to work, perform the "demist test" (with the engine running). If the fan doesn't run, it's a faulty resistor. If the fan does run, you have an overheating problem. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.