Hi there,
Can anyone help me please, ive a 1990 4x4 sapphire cosworth and am looking for a fuse box diagram in relation to the relays, im looking to replace the coolant timimg relay and as the relays are only numbered in roman numerals I dont no which one it is. I need to no what number it is as its discontinued from ford and have source a breaker who can post me one if I can find the location. Ford part number is 6188591. Any help would be greatly appreciated
YF
Jason

 

https://passionford.com/forum/genera...-the-saph.html

 

Have you looked under the top cover of the fuse box?
I thought the description for the relays and fuses is there.
Fuse is 30A if I remember correctly.

 

thanks very much the fuse and relay both are ok so must be something else

 

Wiring on these is notoriously dodgy, also not 100% but it could also be the fan switch which is mounted on the bottom of the radiator.

 

What's the problem?

 

coolant fans are not running, i have wired the fans direct to the battery and they are running fine, ive checked the voltage to the temperature sensor and have removed the temperature sensor plug and bridged the wiring of the sensor to act as if the radiator requires cooling, from there the relay does not click on nor does the fans operate. the fuse board all seems fine nothing melted. I am thinking of by-passing all of this and wiring a 30amp relay from the battery with a timing circuit. does anyone know how long the timer delay is after the temp probe has switched off.

 

If you bridge pins 30 (from battery) and 87 (to fans) on the relay socket the fans should run. (Use a sufficient thick wire.)
That way you can check the wiring from the relay to the fans and from battery to the relay.
Timer dealy after the thermoswitch switched off is Zero. There is no delay. The system also works after ignition off and is controlled solely by the thermoswitch.

I use heavy duty 70 or 75 Amps relay in rally and race cars:
http://www.texasindustrialelectric.c...0332002150.asp

 

Sounds like the relay to me, but I am confused, you said in post 4 that the relay was ok, how did you check it, yet in post 7 the relay isn't operating? Just trying to save you grief looking for another fault that isnt there.

 

As said the wiring is a chronic weak point, along with the fuel pump wiring!

Don't mess around with the standard wiring as it was substandard when new, leave alone now!

Either make your own loom or buy one premade and then rewire straight from the battery.

There is no timer delay, it's merely a thermoswitch that closes at a predetermined temperarture and opens below this temperature, this is what trips the relay which then powers the fans.

The OE switch again is bad, thus "Uprated" switches being avaliable which have a better span than the original.

Martin

 

Hi All,
Sorry for the late reply ive been away working, I tested the relay on the bench and it works fine, I bridged the two pins on the circuit board and the fans didn't swtch on so, Ive rewired the fans with an new relay and bypassed the old circuit board and all works fine now cheers. Thanks all very much for your help
YF
Jason

 

No problem, also ensure the fuel pump wiring is upto the job.

Martin