Rad Fans Not Running - Otter Switch?

[The83Boy]

I'm a little concerned about the fan operation of my 1981 2.2 Elite, so thought I'd seek some 2nd opinions. Perhaps I'm worrying about nothing.

Under normal driving conditions the temp gauge floats about slightly just under 90'C. In traffic, especially during recent hot spells when it's risen past 90'C to around 95'C ish, I seem to be hearing a relay clicking near my feet around this point, but I haven't been hearing any fans kick in. Concerned for the relay, I did some diagnostic tests yesterday. A battery charger and a multi meter proved the relay to be ok on the workbench. Refitting it and shorting the otter switch connectors and then switching the ignition on sees the fans start to spin as if everything is working, so relay, fuse & fans are all good. So maybe the otter switch is playing up, but if it is, why can I hear a relay clicking? Could it be the internal contacts of the otter switch failing so not enough current will flow to operate the relay fully ? If it gets hotter will they 'make' properly and I'll hear the fans kick in? Does anybody know the nominal switching temp of the otter switch? Are there any other temperature driven switches I've overlooked?

I'm planning a (motorway) trip to the seaside on Saturday* so, with 30'C+ temperatures expected, I'd like to boost my confidence that she won't cook if the traffic log-jams.

Thanks,
James.

*Clevedon Cars & Coffee from 9:30am -12:30pm if anyone else fancies it. There'll be 200+ classic/exotic/weird/wonderful cars about the town, I thoroughly recommend it.

[Hawaiis0]

Thermal switches are colour coded by geographical region.

Temperate regions make/break temps are 92/82 coded colour green. Previously was 86/76.

Hot regions are colour coded blue.

Make sure your otter switch is mounted correctly to engage with the coolant and you have coolant in the tank

[AndrewWebber]

Mine start to run at about 90 on the gauge.

Andy

[Alan_M]

When you hear the relay click does the temperature start to fall? If so, then that would suggest fans are working.
Also as Stu says - make sure wires on otter switch are downwards to make sure sensor is always submerged in coolant
Have you let car idle to the point fans should kick in - do they?

[MetBlue]

Air lock in that top pipe can be a challenge. Try squeezing the pipe to see if it feels 'full'.

[The83Boy]

Thanks for all the suggestions.

Turns out the fans just aren't as noisy as I remember and all is ok. Even survived a jam on the M5 while plod cleaned up after some idiots.

The fan's don't come on for long, but that's probably because the otter switch is in close proximity and opens again quite quickly.

Top tip: After mucking about with the switch wires make sure they're tucked away from the fan blades. No damage done fortunately, just a worrying noise.