Wiring in a radiator fan switch

[finch wxm]

What the best way to do this ?

Found out my rad fan doesnt operate while it was at birchdow.

I want to run a switch to it for now until I can figure it out. If put 12v directly to it its fine. Tried swapping the relays to see if it was this but the same so possibly a break in the wiring somewhere I will need to investigate

 

[barnesautos]

If you pull off the coolant temp sensor , the ecu detects the open circuit and activates the fan control circuit. This would help in wiggling the wires about and checking for poor contacts , and then hopefully it will spring back into life.

Easiest way would be to trigger the relay with a switched Earth , but that’ll only work if the rest of the wiring circuit are working.

The other solution is to supply power to the motor directly via a switched relay.

 

[Brigsy]

Prob easier to diagnose and fix it than wiring a switch up mate. Prob a relay fault, id do what @barnesautos suggested above, or if you have clip you can cycle the rad fan whilst testing.

 

[finch wxm]

Prob easier to diagnose and fix it than wiring a switch up mate. Prob a relay fault, id do what @barnesautos suggested above, or if you have clip you can cycle the rad fan whilst testing.

Yeah I don't have clip. The fan works if I directly give it 12v. The relays that were in the car were quite new but weren't renault ones. Do If I disconnect the sensor while running or before I start the car ?

 

[finch wxm]

If you pull off the coolant temp sensor , the ecu detects the open circuit and activates the fan control circuit. This would help in wiggling the wires about and checking for poor contacts , and then hopefully it will spring back into life.

Easiest way would be to trigger the relay with a switched Earth , but that’ll only work if the rest of the wiring circuit are working.

The other solution is to supply power to the motor directly via a switched relay.

I tried disconnecting CTS sensor it's not triggering the fan. Also tried another set of relays which are new so will have to test wiring and also bridge just to rule out the relays. Its could be an ecu signal issue.