rover electric fan

[haynes]

hopefully cooperman may be able to assist as hes got the very vehicle in question. On a 1990 carb cooper ive got an electric fan that used to work off an automatic switch connected in the thermostat housing. This is broke, ive changed the housing anyway and the replacement switch costs a fortune. To wire the fan with a manual switch do i just go from a suitable 12v source to a switch then to the fan? Or can a switch be wired across the 2 wires that went to the automatic switch?

[phil hill]

Haynes

Been there, done that. The little switch in the 'stat housing is about £40 if you can find someone that still has one. Curious thing is the later one that fits in the radiator is only about £25........

You can simply wire a switch across the 2 wires that went to the old thermo-switch. I've use a spare rear window heater switch (because I've got one), mounted next to the rear fog lamp switch, lashed up with a couple of pieces of choc-block, some small 'finger' crimps into the waterproof plug, and a length of figure 8 bell wire.

[haynes]

all i have left is 2 wires from the fan which go into a socket. Ive tried stuffing a wire across the 2 connections and nothing happens. I cant see any other wires going to the fan so i thought i might need to feed 12v in there somewhere.

[Cooperman]

Hi Haynes, do you want the thermostat housing switch off my car (free of charge)? I am taking mine out and connecting manually as that is best in a rally car. The idea is that if the temp gets too high in a 1330 cc car it's difficult to get it to go down again, but if the temp is normal and one is queing at the start of a stage you flick on the fan and that stop's the temp from going up in the first place.
Hence my temp switch is no longer req'd on my car. If you want it I'll post it to you next week.
Alternatively, find a fused circuit with at least a 15 amp fuse, go from there to a switch and from there to the fan 'power-in', then earth it to somewhere suitable. I shll use all new wiring on mine to ensure reliability. I always put a small warning light in the circuit.
It's funny you should ask today, as I have told Chris spennewyn that I'll call in later this afternoon to check on exactly that on a car he's doing for a customer - thanks for reminding me!
All the best,

peter

[annodomini2]

if you can find a temperature sender to fit the hole, you can wire up a simple filter and trigger circuit with a relay to do the job, if you can find drawings on the net for hysteresis then your laughing. I would make it tunable though so you can set it up.

[haynes]

do you want the thermostat housing switch off my car (free of charge)? I am taking mine out and connecting manually as that is best in a rally car. The idea is that if the temp gets too high in a 1330 cc car it's difficult to get it to go down again, but if the temp is normal and one is queing at the start of a stage you flick on the fan and that stop's the temp from going up in the first place.


Hi cooperman, like you i want to manually keep the temperature down with a switch in the car. But many thanks anyway for the very kind offer of your redundant switch.

[Cooperman]

Hi Haynes, I think you are wise in doing that. The automatic temp switch is just something else to go wrong after all (in addition to the bloody transmission!).
God luck with the installation. Don't forget that a warning light is a good idea as well.