Rad Fan Problem - Electrics

[mingblus3]

Hello,

I am trying to re-instate my old radiator and fan as I'm putting the car back to OE. I have got the fan motor connected successfully and can get the fan to run if I bridge the relay connectors 3 - 5 together.

However If I take the 2 wires that I believe should connect to the thermostat on the side of the radiator and join them together the fan does not come on.

Am I not getting something here? I have a spare rad sensor but I don't think this is my problem. I was hoping to get all this tested before putting the radiator back in the car.

I have checked that I have voltage at the end of the wires.

I have swapped relays and also checked the fuse in the dash and all is fine. The ignition is also on.

Can anyone help?

Cheers

[B18ftMOJO5]

Sounds like you tried everything. Maybe the motor is burnt out on the fan

[mingblus3]

The fan is fine as I can get it to work with a direct supply or by forcing the relay open.

[SCHWARTZ]

Make a seperate circuit for the fan there's info on the site how to do it using the alt as your live feed, that's what I did anyway.

[markg]

If you bridge the two contacts on the rad temperature sensor connector together the fan should run if all is well. As that is not the case and you have tested the fan works and the relay it sounds like a wiring problem somewhere. Best bet is to get the multimeter out and start working back. You could double check the relay as I believe the fog and perc fan relays are possibly the same and its a quick job to swap. A common mod back in the day, although I never really understood why, was to put the fan on a switch in the car. I don't suppose a previous owner has done this in your case have they and hence the original wiring is now defunct ?.

[mingblus3]

If you bridge the two contacts on the rad temperature sensor connector together the fan should run if all is well. As that is not the case and you have tested the fan works and the relay it sounds like a wiring problem somewhere. Best bet is to get the multimeter out and start working back. You could double check the relay as I believe the fog and perc fan relays are possibly the same and its a quick job to swap. A common mod back in the day, although I never really understood why, was to put the fan on a switch in the car. I don't suppose a previous owner has done this in your case have they and hence the original wiring is now defunct ?.


I've done exactly as you have mentioned, swapped it over with the relay in the bulk head but the same problem. I'll have to trace the wires back, there has been a previous modification and a switch inside at one point. However I want to get it all re-instated which is why i'm struggling slightly, if all else fails tomorrow I will wire in a switch just to drop the car off.

[markg]

If you have not already done so it would be worth investigating the wiring from the switch that had previously been fitted to see exactly what they have done to get that wired up. Might give you some clues as to whats been altered. There should be a wiring diagram in the back of the haynes manual as well. It wont be much, just needs a bit of investigation and head scratching no doubt. As you say you can always fiddle it if you need to use the car in the mean time.

[mingblus3]

thanks Mark, I'll spend another couple of hours tomorrow morning and do what you have said with regards to tracing back from the switch.