Fans have stopped working on the saff, not sure why.. I have run 12 volts across them and they power on, what switches them on? I have a secs and that displays the water temp correctly so it isnt the sensor..

 

Sound like the fan relay has gone screwey mate. It is in the main fuse box up by the bulkhead. Not sure which relay it is but it should be marked on the cover. If it isn't the relay then the fan switch which is mounted in the bottom LH side of the rad may have given up the go.
HTH
Andy

 

the switch is on the back of the rad not far from the pipe that goes to the water tank on the inner wing pull off the connector if it has not fallen off already turn on the ignition and short out the two connections on the plug the fans should start running if they do and after reconnecting and getting the car up to temp the fans still dont run the thermal switch is not switching the fans on and needs changing

 

thanks guys some good tips there cheers, little job for the weekend

Thanks

 

Could also be that the fuse/fusebox has melted m8

Had it happen on both my saphs

30 amp fuse front row nearest the inner wing

 

Let us know how you get on mate!!

 

I used to make a loom which replaced the whole fan control system on 2wd Sapphs as the fues box usually melts.

Bridge the fan switch out on the bottom of the rad if they spin up then the switch is fooked. If they still don't work, look in the fuse box...

 

I had a quick look at the fuse which is fine, I cant tell which relay is for the fans however and there no clue on the fuse box cover.. No had time to bridge the sensor yet but will tonight.

Thanks guys

 

i have the same prop with my 2wd saph i have tried bridgen the wires to the fan sensor the fans start put then shor out

 

yep - mine melted

 

fuse for fans is marked with a snowflake symbol. relay is the closest one to that that fuse. in all likelihood the fusebox will be melted

 

OK quick update, tried bridging the switch connector and all I get is a clicking from the fuse box area. Nick I have found the fuse its marked with a fan on mine, not sure which one is the relay though.. They are all marked in roman numeral's, I cant even find anthing about it in the manuals.. nothing looks melted however.

 

i thought that the one marked with a fan is the one for the heater blower, bizzarely. are you sure? run the blower and then pull out the fuse marked by the fan and see if it stops.

your fault still sounds like the common melted fuse box. the switch is clearly working the relay, but the relay either has no feed to switch because of melted corruption, or the output can't reach the fans cos of melted corruption (can't remember which way around it is). i had exactly the same problem.

 

Good idea Nick I will try that tomorrow, where abouts does the melting show itself?

 

Round the fuse or under the fuse inside the fuse box....

 

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DazC, our resident electrical expert is correct as usual

 

all i can remember is the relay is listed as an engine management relay in the book, the holder is red, and i had to buy one from an autofactors as the genuine one was £12 and a pattern 30amp relay cost me £2

i will have a look tonight and let you know what number, its definatly not one of the high up ones at the back though

HTH
Pugo

 

the relay is the closest one to the fuses, on the outside of the car if that makes sense. well it is on lhd anyway.

 

OR rad is blocked.If rad is cold at the bottom when engine up to operating temp, then its blocked with crud at the bottom just where the fan temp sensor is. Soultion have your rad recored or exchange rad from pj.

 

cooling fan fuse is no 11 (green 30amp) i think the relay is no XII or VIII, in the sierra owners handbook they are listed as being for the automatic transmission inhibitor and kickdown respectivly

 

It's not that because it doens't work electrically even when the fan switch has been bridged out.

Check that there is power on the fuse, on both sides...

 

the temp the monitor is indicating is a differet sensor to the one used to switch the fans on, the fan swaich is mounted in the core of the rad itself , half way down near the ignition coil side IIRC... this then controls the large green relay near the battery which switched the power to the fans themselves... ive had the big relay fail before...

 

Thanks for all the help chaps its now sorted!!!

I found the replay and on close inspection saw some burn marks near the bottom of it, i prized it out and the pins were a little melted (as you guys suspected) I bent the pins and put the replay back and bingo the fans kicked in as the switch was still bridged. Took it for a run and everything works as it should.

Is there anything you can do to stop the fuse box melting?

 

the biggest problem is the fuses and relays go a bit manky on the terminals which causes a resistance between the fuse/relay and the fuse box which in turn genarates heat, melting the fuse/relay etc.
the best way to conunteract the problem is make sure all the fuses,relays and fuse box have clean and shiny contacts and use electrical grease or vasiline to stop them corroding again.
done this with mine and not had no problems since

P.s. take every thing out one at a time so you know where they go back.

 

The problem is the fans draw nearly 30 amps on a 30 amp fuse which means it gets warm. The only way is to renew everything or rewire it and use a 40 amp maxi fuse....I have had to do this a few times.

 

Glad your sorted m8

Going to wire my fans up threw a relay direct to battery,so the current going threw the original fuse in fusebox is only the current to switch the new relay
Same as people do with the wiring for the fuel pump