[Reekyg]

Hi Guys, please can anyone help me. My 156 1.8 SW is running fine but when in traffic the temp will eventually go above 90. Not overheating though but the radiator fan is not kicking in. Here's the the thing though I have replaced the thermostat, (new) plus new sensor (behind the radiator) and also replaced the black Relay in the box infront of the battery. I have also checked the 50 amp fuse all is fine. I just can't work out why it's not kicking in.

When I take out the black relay and put it back in the fan will start for a few secs and stop once it clicks. I have even run a wire over the relay terminals and jumped it and the fan runs. But permenantly.

So has anyone have any suggestions as its a driving me nuts.

Many thanks.

 

[David C]

The only temperature sensor is the one on the thermostat housing.

The part on the fan housing is just a resistor which is in the low speed fan circuit.
There are two relays for the fan, a big one for the full speed and a small one for the low speed.

How far above 90degC has it gone?

Have you tested high and low speed via diagnostics?

 

[mirlock]

pull off thermostat sensor plug while running engine if the fan runs its either the sensor or the resistor .(resistor normally being the problem)

Edit .. damn that david he got speedy fingers beat me again :lol:

 

[Reekyg]

It goes to about 110 but no higher and then will drop down. Sorry you were right I changed the resistor. Which is the 2nd relay?

Thanks

 

[David C]

Which is the 2nd relay?

The small relay bases should be colour coded.
The one for the low speed should be the one in the black base.

white base = AC
red base = fuel pump