Coolcat Mitsubishi thermoswitch

[Gfhug]

My Coolcat Otter switch seems suspect so I bought a replacement Mitsubishi MB007639 thermoswitch.
Before fitting it seemed worth checking it, at room temp open circuit, so far so good, but sat in boiling water it is still open circuit. Same results when checking the original Coolcat switch.
Am I doing something wrong or are both for the bin?
Having bought the replacement from fleabay long enough ago it's not worth sending it back.
Can anyone point me to a reliable (fleabay?) source, please?

Thanks

Geoff

[Robbiee]

Have you tried Fosseway engineering? They do a modern version of the otter switch...I have one and it seems to be fine
Robbue

[Gfhug]

Hi Robbie, the Fosseway is the same as the Coolcat. They both use a more modern thermoswitch in a housing.
Thanks

Geoff

[PeterCrespin]

I thought Mike Frank used a Peugeot switch for some reason. One might expect it to shrug and behave unpredictably post-Brexit...

[Bob.]

Hi Geoff,
I don't think there is anything wrong with your test technique in principle. The sensor I found on the US fitted system on my S3 having a M16x1.5 thread, looks identical to the one Mike Frank shows on his Coolcat website for a S1/2 supplied system.
When it packed up I found it was fitted to various 1990s Mitsubishis and I bought a NOS Intermotor 50430 and a NOS Lucas SNJ202 which are equivalent to the Mitsubishi MB007639. Stamped 85/80 the Intermotor was actually operating at 93/84 and the unmarked Lucas at 92/83 using the hot water and thermometer test. I fitted the Intermotor and it worked OK last year.
The ebay suppliers I bought from in 2018 don't offer them now but others do so probably worth trying again.
Hope this helps,
Bob
Failed top, new bottom in image

[Gfhug]

Bob, thank you for that info. I've now ordered a couple more thermo switches and let's see if they test properly.
This might explain why the car overheated last year when stuck in traffic. I'd have hoped the Coolcat unit would have lasted a bit longer than it did, but that's life.

Cheers

Geoff