Radiator fans on continuously?

[my250gt]

Fault has recently developed on my '92 griff where the cooling fans are on even when engine is cold.
Was fine before I washed it! 😁
Disconnected both connections to the otter switch on the expansion /swirl pot, fans still turn on as soon as ignition is on.
Have to remove the fan relay before they will not run. Swapped for new relay, still same problem. Relay is switching as soon as ignition goes on.

Am I looking for an earth short in the engine loom or something?

Any ideas?
Thanks, Phil.

[Stew Mc]

Have you got a fan override switch under the dash which you may have accidentally turned on? Just a thought.

[my250gt]

That's a thought but no switch that I'm aware of? Will have a look, guess I will need to trace the wire back from the engine loom to the the fuse box...

[2 sMoKiN bArReLs]

my250gt said:

That's a thought but no switch that I'm aware of? Will have a look, guess I will need to trace the wire back from the engine loom to the the fuse box...

If it's like a Chimaera, people often use the dash light switch by your left knee.

[QBee]

I think the wiring is shorting to earth.

[my250gt]

I did press that dash switch the other day as the gauges weren't back lit and they didn't come on either. Will check that first. Then it's looking for a short.

[my250gt]

2 sMoKiN bArReLs said:

my250gt said:

If it's like a Chimaera, people often use the dash light switch by your left knee.

Well worth a try but no, not that. Will have to trace wiring

[Penelope Stopit]

When you unplug and plug in the fan relay do you hear it clicking? if there is no clicking relay it could be faulty due to welded or sticking contacts
Try an identical relay for a swap and test if you haven't already done so

[my250gt]

Out of interest, has anyone replaced the original fuse box for something straight forward? There are some nice relay fuse boxes out there now.

[Penelope Stopit]

Yes

[my250gt]

Penelope Stopit said:

Yes

What did you use?

[my250gt]

Penelope Stopit said:

When you unplug and plug in the fan relay do you hear it clicking? if there is no clicking relay it could be faulty due to welded or sticking contacts
Try an identical relay for a swap and test if you haven't already done so

Yes clicks as I plug it in, ignition on. So this suggests an earth short?

[5.0ltr]

Some thoughts here. https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Loubaruch]

This may help:

http://www.bertram-hill.com/cooling-fans-schematic...

I must redraw that diagram it looks decidedly rough.

[my250gt]

5.0ltr said:

Some thoughts here. https://www.pistonheads.com/gassing/topic.asp?h=0&...

Looking at how the insulation has crumbled on those wires it's a strong possibility that's my problem too. Will have a look through the engine harness..

[Penelope Stopit]

Loubaruch said:

This may help:

http://www.bertram-hill.com/cooling-fans-schematic...

I must redraw that diagram it looks decidedly rough.

Would you like a link to some free drawing software that works on Linux or Windows? I can draw it and mail it to you if you wish