fan sometimes comes on too early

[softtop]

Anybody have any idea why? The fans are coming on at about 60 degrees. The temp gauge is ok since I have disconnected it to get the engine temp up to 90 and then the fans keep the temp about 70 after that.
Why are they coming on so early?

>> Edited by softtop on Monday 30th January 20:08

[Chris Smith]

Try changing the otter switch. According to the bible, it should be a 92/87 version (on at 92 and back off when things have cooled to 87).

[shpub]

Errr if the temp guage is disconnected... how do you know what temp the fans are coming on?

[softtop]

Bad use of english. I have disconnected the otter switch to test it out. It is the third one I have fitted. The first two appeared to be faulty when bench testing them. This unit can let the engine warm up normally but most of the time, start the fans coming on at about 50-60 degrees.

[leorest]

Must be to do with the respective locations of the gauge sensor and the fan sensor aka otter. That is to say the otter correctly reads trigger temperature (we know this 'cause you tested it out of the car) and switches fans on but gauge sensor is in a different part of the circuit measuring a different temperature!

All the Beast
Leo

[greenv8s]

If you've bench tested the otter switch you know what water temperature that switches on at. If the gauge shows a different temperature at this point then the logical conclusion is that the gauge is misreading. You could verify that by putting the temp gauge sender in a cup of water at a known temperature and see what the gauge tells you.

[softtop]

Is this a record? I have the fitted the fourth new 87-92 switch and the temp rises as planned. The last three have worked for about a few weeks and then failed. I will update if this happens again. Always Intermotor, anyone know of another manufacturer if this one goes faulty?

Softtop

[zippee]

Intermotor switches etc are the biggest pile of poo out.
If you can get hold of the original Lucas units they work so much better, but I believe they are very hard to get hold of now.

[softtop]

I cant find a wholesaler, is it unipart stockists?

[radzoule]

Slightly different fan problem, but quite odd - sometimes if the fans are running when I cut the ignition they continue to run. If I turn the ignition on again, they immediately stop. If I don't, they continue to run until the battery runs out.

Suspect there's a bad earth somewhere, but wondered if anyone else had experienced it. I had to get trailered home not so long ago for a timing cover gasket. The guy drove the car up onto the low loader and the fans stayed on. I couldn't hear what with the noise of the truck. When we arrived at our quiet destination some 2 hours later the fans were still running (quite eerie)and there was only just enough juice to turn the engine over. Credit to the guy - he didn't look that surprised. We Tivvers must be bread and butter to the recovery agencies