I have twin fans on my RST.

I need to wire in a relay for them as the keep popping fuses.
However, im confused as to how to wire it in. I have a switch on the dashboard for manual overide but would like the sender to work as well.

Is it possible to wire in the switch and a relay to the standard loom for the fan sender? if so would someone be able to explain or knock up a quick diagram of where certain things need to go. (or just give me an example of how you have wired in your twin fans, seperate or together etc) im really stuck here

thanks

 

anyone?

 

bttt

 

I did this a few years ago. I had one fan controlled by the normal fan switch and then an override switch in the car that would switch on BOTH fans regardless of the state of the fan switch.

Not sure I can remember how I did it though! I'll get back to you if I can remember!

 

You might be better off getting your self one of these pre made looms (he states for cosworth but I think these can be fitted to rs turbo too - depends on connections).

http://cgi.ebay.co.uk/SIERRA-ESCORT-...3A1%7C294%3A50

In principle however you need to tap off the wires from the fan switch to trigger a relay which take its feed direct from the battery (fused) and feeds the second fan.

So a typical relay looks like this...



You would connect pin 86 to the wire on the fan switch that becomes live when the fan kicks in.

Pin 85 to ground

Pin 30 to a permanent live

Pin 87 to the +ve on your second fan.

Need someone to verify this because I cant for the life of me remember if the wires going to the fan switch are live or earth! If they're earth then the wiring would be slightly different.

 

thanks man, im gonna have a go today and see how i get on.

 

This is what I've done on mine (not an escort):
Relay 1 uses the 12v supplied from the dash switch to activate, relay 2 has a permanent 12v and uses the earth from the rad switch to activate (not sure if the Escort is negative or 12v), I tend to put an LED in the dash too, it comes in handy if your exhaust is louder than your fans lol

 

Good luck! just double check that the fan switch is on a live circuit and not -ve if you go by that diagram coz I just cant remember which way round it is!

 

if the radiator switch on the escort is 12v would i have to run live from that and just earth the second relay the same as the first.?

 

Yes I think you would.

 

ok cool. im gonna go have a look now then, thanks for the input guys! big help. wish me luck lol

 

Managed to get it done. By about 10pm! lol. i do struggle with wiring, but all is working. Thanks alot for the feedback. Diagrams and descriptions helped alot.

The car is going for a diagnosis on the dyno 2moro and didnt want to miss my booking.

thanks

 

Nice one! How did you wire it up in the end?

 

I wired up one of the fans to the temp sender (using normal loom) and the second to the switch via relay. It was obviously the strain of both on the standard loom.

Was going to wire it up similar to "shonky"s set up. But i didnt have enough spade connectors! lol and i needed it to have some form of cooling today to get it to the tuners this morning! Managed to get it done by 11 last night!

 

ah, so you've got one fan running from the original wiring controlled by the normal fan switch, and the 2nd one is controlled purely by your override switch.

does your override switch also turn on the original fan at the same time or just the 2nd one?

 

just the second one as i didnt have enough wire or spades to relay the second fan as well. Thats why they kept popping the fuses cos the two fans need so much juice when running the same circuit.

Im gonna do it so both are controller by the sender and the overide switch another day especially since the car is now sorted.!!