doz · Jun 4, 2013

Hi all. The elec rad fans don't seem to work. Are they controlled by the hevac only? I've checked fuses under bonnet and I've also pulled the fan relays which are the two nearest the battery and nearest the wing. I bridged the contacts and still no fans. The two relays do get warm and I have power on the trigger and supply to the relays. However I have no power at the fans when bridged. Is there any other control box between the relays and the fans?

palace · Jun 4, 2013

Thermostatic control ?

dogsbody · Jun 4, 2013

Unless somebody has been messing around the electric fans are for the air con.

doz · Jun 4, 2013

Well the plot thickens. It would of also helped if I had been farting about about with the right relays.

Right I've got the fans to run by bridging the right relay. Now here's the strange thing. On the 4 pins of the relay you have trigger feed, earth for trigger, supply for fans and the wire to the fans. Hope that makes sense. I managed to get the fans to run by using an alternative earth for the trigger. Now here's the strange thing the trigger earth on the fuse box has for some strange reason a positive 6 volts showing with the ignition on and 1 volt with the ignition off. of course with a positive voltage showing the relay can't work. I can't for the life of me work out why that is happening. I worried this is the start of the dreaded fuse box failure however I have no signs of melting.

Datatek · Jun 4, 2013

doz said:
Well the plot thickens. It would of also helped if I had been farting about about with the right relays.

Right I've got the fans to run by bridging the right relay. Now here's the strange thing. On the 4 pins of the relay you have trigger feed, earth for trigger, supply for fans and the wire to the fans. Hope that makes sense. I managed to get the fans to run by using an alternative earth for the trigger. Now here's the strange thing the trigger earth on the fuse box has for some strange reason a positive 6 volts showing with the ignition on and 1 volt with the ignition off. of course with a positive voltage showing the relay can't work. I can't for the life of me work out why that is happening. I worried this is the start of the dreaded fuse box failure however I have no signs of melting.

Look at RAVE, there are 3 relays involved. the fans can run at full or half speed. Jumping pins on things you don't undertstand can only lead to grief on a P38. The relays involved are 13, 14 & 18.

doz

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palace

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dogsbody

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doz

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Datatek

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