Fans not working...

[chris1972]

Okay, before you say 'Otter Switch', the fan override isn't working either! I did a short trip to Tesco today. Car got hot as normal and I heard the fans come on (sounded quiet). Double checked and only the passenger side fan was working. When I returned to the dual carriage way, the engine cooled as normal. Retuned home and looked at the fuses (glow fuses) and none of them were glowing. Now both fans aren't working and I'm unable to switch them on via the fan override switch. I'm stuck indoors for a while with my daughter as she's hay fevered to the eye balls, but would like to try and go direct to the problem when my shift relief arrives!

Any ideas? To summarise:

1. I don't think it is the otter switch as one fan came on as normal before it stopped working altogether
2. The override switch isn't switching the fans on, although the LED lights up
3. I can't see any blown fuses (glow fuses), but will swap them manually later
4. Too much of a coincidence for both relays to go at the same time?

Edited by chris1972 on Friday 5th July 14:23

[Harrytsg]

Check the fan connections at the fans, these are known to get dirty and fail.

[marcus1875]

Harrytsg said:

Check the fan connections at the fans, these are known to get dirty and fail.

i agree. i tend to check mine each time i go for a blast. but that is probably cause i wired them up myself and im terrified i effed it up.

[chris1972]

Okay, thanks for this. I'll head out with a bit of sand paper and some WD40 in bit and give them a good clean. I noticed that my fans remained on a lot longer the other day in traffic, which is probably due to just the one functioning and it taking longer to cool the car. I recalled Sardonicus saying he found only one fan working, which is why I decoded to check. Pleased I did now!

[chrispitman]

Earth fault if fuses are still ok, try checking the earth point at the front of car end of main box chassis member, also check for broken cable/crimp at this point

[chris1972]

chrispitman said:

Earth fault if fuses are still ok, try checking the earth point at the front of car end of main box chassis member, also check for broken cable/crimp at this point

Okay, cheers. Where is the earth on the rad? Is it underneath?

If it's very difficult to access, is it worth getting another earth made up and connecting it to the base of the swirl pot from the rad? Where would be best to connect the earth to the rad?

Edited by chris1972 on Friday 5th July 14:49

[Harrytsg]

The main earth is at the front by the rad, its a pain to access IIRC.

To prove your earth (one way or the other), connect a fly lead to the battery negative and then use this to provide the earth at various points accessible to the circuits.

Obviously, you need the ign on, and otter sw shorted to replicate the scenario of wanting your fans on.

You could also do the same with the live, but, tbh, you could sort a lot of this with a simple multimeter.

[chris1972]

Cheers for that. I mat get a few extra earths made up and connect another from the rad to the swirl pot base. Meanwhile, I've got the fans working again after giving the fan connections a damn good cleaning and spraying with large amounts of WD40. I've gaffered the connections up now as an extra precaution. I'm going to head over to the marine place to get an extra few earths made up and the ends properly crimped, but at least this should sort out the cooling!

Thanks for your input.