where to install a temp sensor?

[kapnklug]

I'm looking for a place to install a thermocouple for a temp gauge (murphy switch) in my '85 M1009. Both the ports on the cylinder heads seem to be occupied. Is there any other place to get into the coolant, other than T-ing into a heater hose with a pipe fitting?

 

[319]

Found this picture a couple of days ago when doing a search in the CUCV forum. The poster mentioned buying a threaded adapter at a GM dealer to fit in this port. Don't remember who posted it and I hope they don't mind. Hope it helps.

 

[Armada]

That would be me. I don't mind, in fact I went out and took some pics of the threaded plate itself and the p/n for it. The pic above shows the probe installed on the passenger side head. Remove the block off plate (shown below) and install the threaded plate and gasket in place of it. After attaching the probe, and after start up and reaching operating temp, you will need to go back and carefully loosen the probe to bleed off any trapped air in the pocket below the probe. Also, if you install a block heater you may have to bleed any air off again. If the gauge ever stops reading the coolant temp, always check for air trapped first. I had this happen before and it was a bad head gasket allowing air to be compressed into the coolant passages. Truck ran fine and never would have know it was bad otherwise. Hope this helps.

 

[84cucv1ton]

i will be doing this myself

 

[RockyM1028]

How reliable of a reading would u get from T'ng into a heater hose??? Seems to be a much easier install? Would't u need to have it flowing at all times through the core? That would suck during the Hot summer!

 

[kennyw]

How reliable of a reading would u get from T'ng into a heater hose??? Seems to be a much easier install? Would't u need to have it flowing at all times through the core? That would suck during the Hot summer!

There is an air diverter valve in the cab that sends the hot air down the side of the cab with the heat shut off. The coolant flows 100% through the heater core 100% of the time (unless you disconnect the hose).