after doing loads of electrical work on my car loom, ive had the engine running today for the first time properly and i have lost the fans and its not the switch, its wiring... if i bridge any combination on the loom plug it wont come on..

can people please tell me what all 4 pins do the fan switch and the order there in? where those wires go to ? wheres the relays are?

i have removed the aircon from the car if i press the ac button the fan does come on.

i also have a four pin connector that use to plug to the gas canister thing on the aircon could this need linking up?

cheers

 

www.escortrscosworth.com

 

any help would be great... thanks

 

I've removed my aircon and not bridged anything, all my fans work

 

I hope this helps. I think it goes like this. firstly the 2 speed relay is located in the battery tray aea, behind the battery on a plastic pannel, the big green one is thefan speed relay, the other big grey one is for the heated screen (i think).
The switch is on the bottom of the radiator on the passenger side, it had a bosch multipin connector with 4 wires on it, 2 brown wires, 31-118c and 31-18b are ground wires (earth). The other 2 wires are brown/black, 31b53b and 31b51a are the speed control wires for the fans, they switch at different temps, to bring the fans on at the 2 speeds. Actually what this relay does is in the slow speed the fans are in series (slow) and at the higer temp the turn the relay over to put both fans in parrallel (fast).
To test the fans and the relay you will have to ground (earth out) the brown /black wires one at a time and see if the fans start up, one will bring them on fast and the other will bring them on slower.
The main fuse for the fans is one of the big 50A ones in the auxillary fuse box, wire no 30-27 red green, attatched to the battery positive post.
The fan motor 1 wires are + positive red/green 30-27a and - negative black/blue 54-34 The fan motor 2 wires are + positive black /red 54-31 and - negative brown 31-18, 31-18 is conected direct to ground (earth) 54-31 black/red goes to pin 7 on the big green relay, 30-27a red green is soldered to the main feed wire 50A feed in the loom somewhere so this is permenent live all the time, the other wire on this fan, fan1 the 54-34 black/blue, goes to the big green relay also.
The principal of the relay is that when the water temp reaches the lower level it brings on the both fans in series via one half of the relay, if however this is not enough to cool the engine then as the temp increases the other half of the relay switches on and puts both fans on is parrallel (the fast speed).
Also there is a 2 pin connector no.VC-2250 wire nos. 31b-12 brown/green and 31-23b brown, this goes to the aircon system. I dont know for sure but i think this will turn on the fans on slow speed while the air con is being used. The wire 31b-12 brown/green from the aircon connector goes to the large green relay and will be used as a switched live + to turn on the relay, in theory you could also put a live wire (temporary short) from the battery to test this part of the circuit, Lastly i have not tried any of these tests but from reading the wiring diagram i think this is how it works. Hope this is not to difficult to understand.

 

thanks mate really good advice, ive found it be a faulty loom connector on the switch, ive been down the scrapy and got a loom plug that fits a 2wd set up, wired that back to the relay and paired up the brown/black wires, fited a 2wd switch now they both come on together at full speed which i think is better as the 2wd comes on earlier... also my old air con switch is now a nice override switch.... with out adding any tacky switches....

thanks again..

 

just got my escos running - any idea of how long at idle I should be waiting roughly before the fan(s) kick in as not sure they work ?

 

That can depend on a lot of things, air temp, how hard the car has been driven up to the point that you stop the car. On a warm day & the car up to normal operating temp the fans would come on within a few mins of stopping with the temp gauge at the half way point.

 

the car on tickover stationary ( roughly ) as it isnt on the road as yet...

 

from cold at idle, it may take 25 mins for the fans to kick in - if you held it at about 2.5 - 3 K for 5 mins once there was a bit of temp in the oil it will get hotter faster with no damage. usually kicks in when the needle is just over half way in the gauge.