Otter Switch

[ABT]

Hi Chris. Thanks for that. Unfortunately the previous owner seems to have rewired the whole system (hence the change away from the otter switch) so fan 1 runs permanently when ignition is on, even with both otter switch wires connected! I can't make head nor tail of what he has done!

[amarshall]

Hi Chris. Thanks for that. Unfortunately the previous owner seems to have rewired the whole system (hence the change away from the otter switch) so fan 1 runs permanently when ignition is on, even with both otter switch wires connected! I can't make head nor tail of what he has done!

Check the fan relay - this symptom is typical of what happens when a changeover relay is (incorrectly) used instead of a double-pole switch.

[RRHANS]

I am having the radiator recored and tread added to put a conventional thermo switch in the rad.
I did the same thing to my TR6 and it is a fit and forget solution.
I do not want a second head gasket failure.

[ABT]

Hi Chris. Thanks for that. Unfortunately the previous owner seems to have rewired the whole system (hence the change away from the otter switch) so fan 1 runs permanently when ignition is on, even with both otter switch wires connected! I can't make head nor tail of what he has done!

Check the fan relay - this symptom is typical of what happens when a changeover relay is (incorrectly) used instead of a double-pole switch.

I figured it may be that. However, having tested with the relay from another Excel which has correctly functioning fans, the fan just didn't come on at all. Hopefully if I can get this Kenlowe thing working I can ditch the otter switch and housing completely! Still, your comments do give me hope that maybe I can still get power from the otter switch wires.

So if I take power from either the wire or the starter motor, where can I rig up ignition for the module power?

I'm desperate to get this sorted, I've only driven the car once!

[amarshall]

Hi Chris. Thanks for that. Unfortunately the previous owner seems to have rewired the whole system (hence the change away from the otter switch) so fan 1 runs permanently when ignition is on, even with both otter switch wires connected! I can't make head nor tail of what he has done!

Check the fan relay - this symptom is typical of what happens when a changeover relay is (incorrectly) used instead of a double-pole switch.

I figured it may be that. However, having tested with the relay from another Excel which has correctly functioning fans, the fan just didn't come on at all.

DId you check it with the otter switch wires shorted together ?

An incorrect relay will cause one fan to run all the time, a correct relay with a failed otter (or the wires not connected) will not allow the fans to run. Shorting the wires together emulates the otter switch closing at temperature.

[ABT]

I haven't tried that actually. Although as both relay and otter switch are brand new last week I just don't know. I will give this a go a little later when I have extra pairs of hands available. Seeing as I have already put a hole in my radiator I will probably give the Kenlowe a shot. It was the otter switch coming out and pooring coolant all over the M25 that drew my attention to the problem in the first place so would be quite glad to see the back of it to be honest!

Any ideas on ignition source?

Edit: I just enlisted the help of next-doors gardener to test it. With the correct relay off the other Excel, touching both wires together had no effect. So I guess it's not wired up! I must remember to add the previous owner to my Christmas card list!

[ABT]

Hi guys,

Finally got it all working today. Thanks so much for all your advice, much appreciated! I'm so pleased to finally have a working Excel

Alex

[don.hasi]

Does anybody know the dimensions of the otter-switch?