I am after a bit of guidance, the radiator fan on my 2001 20v Marea is not working - once you apply some power to the relays it comes on fine.

I have been unable to locate the fault in the wiring and so I plan to fit an adjustable thermostat into the top of the water pipe and basically bypass the current set up and have the fan wired and fused to battery.

Does anybody have any brands they recommend? Or better still any other ideas?

Thanks

the thermostat is just a valve that opens at a certain temperature, how can you adjust that?


fan problems are usually due to rust on the relays and wiring connectors (attached to front of battery tray, usually in a small black box)

i'd test/replace the relays and clean up all the connectors.

the fan should not come on when you "apply power to the relays". the fan is negatively switched, which means it should come on when you earth it. it gets a constant power supply even when it is switched off. check it is getting power, if it isnt check the fuse and the condition of the connectors at the fuse and fan.

if your model has A/C then your fan problems probably will be a pain in the arse to fix and you may want to consider wiring a switch for the fan so you can turn it on manually. all you need to do is take the earth from the fan, add a switch to it, then attach it to chassis.

Cheers Jug,

I don't think I was precise enough with my description! I am going to fit a Kenlowe style kit with a sensor in the top water pipe via an adjustable thermostat (in that I can alter the temp at which the fan is switched) which is wired to the battery and fan.

There is power to the fan and when the relays are bridged it does come on - but only for as long as the bridge is in place. I don't particuarly want a manual switch as I do a lot of miles and I would like the fan to be able to kick in when I have left the car ala it should do.

hebby said:

I don't think I was precise enough with my description! I am going to fit a Kenlowe style kit with a sensor in the top water pipe via an adjustable thermostat (in that I can alter the temp at which the fan is switched) which is wired to the battery and fan.

Click to expand...

oh! thats a good idea.
when you say 'thermostat' you mean an electronic switch that is operated by temperature (called a fan switch), rather than the thermostat that is used to control coolant flow, thats where my confusion came from.

your idea is fine, there is no reason why you cant add your own cooling fan control system. the easiest method is to add a cooling fan switch from another car (that switches at same temp) and simply wire it up to the fan's earth to make a more traditional switching system, which is always more reliable, and does away with the relays. i think an older ford could be a good donor for this part, but if you remove the relay you need to check the new switch is ok for the current that will be going through it or it'll burn out.