Fan not working ?

Hi Fan is not working on a curvey have put 12volt direct fan works have changed temp switch in rad any one have any ideas please rgrds pete.

[keith_d]

a) Bypass the rad switch with a piece of wire. Does the fan run?

If not, check the fuse.

If fuse is OK, use bulb to check supply at radiator switch. (Bulb not meter, because corroded connectors might not show up with volt meter).

If power to switch is UK, close the spade connectors slightly with a pair of pliers to ensure they make contact.

b) Check that there's water in the system and no airlocks

c) If all else fails remove radiator switch (again) and test with hot air gun

[embee]

Earthing of radiator/fan mount? Some folk have these sort of issues when they've repainted everything.

Easiest thing is to check continuity between switch body and frame/battery earth.

Hi Thank's yes fan runs if bypassed, fuse ok, water ok, wondered if it could be the coolant temp switch or must be a broken wire?

[flymo]

are you bypassing by shorting right between the temp switch terminals? If so and its then working it must be a dodgy switch.

[keith_d]

Originally Posted by pete sv

Hi Thank's yes fan runs if bypassed, fuse ok, water ok, wondered if it could be the coolant temp switch or must be a broken wire?

Could be corrosion in the connectors that plug onto the thermostatic switch. They're exposed to the same cr@p as the rest of the bike.

IIRC you can test the thermostatic switch by taking it out and heating it in a pan of boiling water then checking with a meter. But I've always found a hot air gun much easier (though less accurate).

Keith.