Coolant Temp Sensor Switch needed ( Lamp type not for temp. gauge )

KenMT372d · Jun 8, 2019

Looking for MT373d Temp. Switch. Think it is a 16M x 1.5 thread. Current Temp. Switch has center terminal grounded to other shell even when cold, keep the Temp Warning Lamp (ON) all the time. Know of any optional replace part numbers / vendors? Only marking on my old temp. switch are a circle with (ND) , [ 108 ] and [ 5 T ].

oliver28472 · Jun 9, 2019

I stole this from an old post. Found it using "search this forum" by typing in "sender": The Beaver has a 3/8 NPT sender unit that is connected to a dash warning light only. No guage was available for the twin cylinder Beaver. According to factory repair manual, the temperature range of the sender must be between 221-232 degrees F. (105-111C). Sender is normally open, and closes if temps reach the ranges listed. Factory original sender unit is EXPENSIVE (over $160), so finding an economically priced substitute would be a good thing. I have begun to search, and have found a couple that might work, but the probe on the substitutes is much shorter than the original. Now, this might not be a big deal at all, but then again maybe it wouldn't register the correct temp, either. I would like to find a new sender unit, complete with the lengthier probe end, that operates by closing the contacts once coolant temperature reaches the range listed here. Thus far, the closest I have found is for the 60's Ford motor company gasoline engines used in cars and pickups.

BTW, I find it interesting that the OEM sender unit does not have a metric thread...when everything else on the tractor has it.

KenMT372d · Jun 11, 2019

I ended up installing an electric temp gauge kit from auto part store. My Satoh 373d with K3E engine has a 16mm X 1.5 pitch thread on the factory temp. switch ( open till hot the goes to ground "closed" ). Still going to look for a N/O to temp. switch with 16mm X 1.5 pitch thread. Thank you for the feedback.

California · Jun 12, 2019

KenMT372d said:
Still going to look for a N/O to temp. switch with 16mm X 1.5 pitch thread. Thank you for the feedback.

That might be the same sender used by Yanmar. Check with Hoyetractor.com. (An early Yanmar specialist).

I've found that some 'Yanmar' parts - ie electrical stuff, steering box, are generic and are the same as used on Datsun/Nissan in the same years. That might be a lead to finding what you need. Boilover temp will be the same for tractors, cars, whatever so you may not need specific Satoh parts for this, just compatible threads and maybe the length of the sensor.

I found my 'Yanmar' low oil pressure sensor was the same as the universal Datsun/Subaru/Toyota/Isuzu sender stocked at Autozone, likewise the alternator and regulator are actually early 70's Datsun as listed by Autozone. Look around!