Manifold Temperature Sensor Alternatives

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.


Mostly stock 1978 FJ40
May 19, 2010
Oxford, MS
I have looked and read a lot of posts about the manifold temperature thermocouple that is in the carb fan cooling circuit but have found nothing about alternative replacements of this sensor. :bang:

I have a 78 40 series in which I have installed a carb cooling fan, currently with a hard line switch on my dashboard with the timing relay and the on/off power relay for the fan. I do not have the thermocouple on the manifold and just acquired the proper bracket for this switch.

What NON - OEM thermocouples will work and have a 12 x 1.25mm thread which would allow me to mount them into the same bracket as the OEM was in?

Manufacturer and Part Numbers?

Are there any cheaper alternatives which would give the same temperature depended switching around 175-190F the original one does.

Probably a hundred forum members have one with the bracket and the original wiring harness connector in a bucket or a coffee can in their garage. Why would you want an alternative?
A pretty simple answer for that is, -- I need a working one in my engine and not in a bucket in someones garage. :) And I seem to not be able to find one. I have the bracket and just need a thermocouple that will do the same job as the original one which one of the POs on my car seems to have removed or it was never there.
You put an ad in the parts wanted forum I guess? Seems like they'd be easy to find.

make offer:

I think it's going to be a PITA to get anything else calibrated correctly, especially if you don't have a good one as a reference.

Something like this could be a start, but I'm sure you'd need additional circuitry for calibration. Also, the plastic isn't going to last long if you wanted to put it in the original bracket.

I just posted in the Wanted section. Lets see what that brings as $89 on ebay is rather expensive. Before I go that route I keep my hardwired switch on the dash.

Users who are viewing this thread

Top Bottom