fuse

[colin mee]

Any one know where the fuse is for the fan.thank

[KKson]

Colin, fuse 52 according to Steve Heath manual. I wired in a manual over ride on my fan last weekend and certainly on mine it is 52 also (1988 350i).

[colin mee]

Did you wire it off the sender or just put a feed to a switch.i cant find the wire that turns it on from the engine.i am trying to put a over ride switch on

Edited by colin mee on Thursday 18th June 21:05

[KKson]

I piggy backed off the switching circuit off the relay. There are two positive feeds to the relay - the switching circuit and the main power circuit. Basically when the otter switch engages it earths the switching circuit which pulls in the relay which then puts main power to the fan. I put a switch parallel to the otter switch going to earth. Basically one wire from the relay under the dash to the switch and then the second terminal off the switch to earth (dashboard steelwork). All works a treat.

[KKson]

Just for clarity, there are two fuses which control the fan relay. Fuse 52 is the main fuse but fuse 9 is the power to the switching circuit. Fuse 9 should also protect the instruments, indicators and dash warning lights.

Green/slate grey is switching power in, green/brown is otter switch feed. Thicker brown/blue wires are the main fan cables.

If you carefully poke a wire into the back of the green/brown contact and earth it then this should energise the relay.

If you've got a multimeter then you should have 12 volts on one of the brown/blue cables (main fan feed from fuse 52) and both the smaller green/grey and green/brown will be live also.