96 B4000 Temp Sending Unit Location??

[beyoko]

My son's B4000 popped two freeze plugs recently (he just had water not coolant in the rad). Just by luck I found them laying in the carport and had him come right home.

He said the temp gauge didn't register hot so I'm suspecting a bad sending unit 'cause I can't imagine it not getting hot with two freeze plugs missing.

Sooo....
1) anybody know where the temp sending unit is, and
2) can I just reinstall the freeze plugs or is there a specific diagnostic/ installation process I ought to follow.

Thanks a million.

[mazdatech]

Your temp gauge wont read if thier is no coolant in the truck.......

[89B2200]

Where are you located at. Are you up north?
The plain water coolant could have frozen inside the block and pushed out the freeze plugs if you live up in the colder states.
Anti-freeze lowers the freezing temp of coolants to prevent freezing inside the block, hoses and radiator.
Mazdatech is right, no coolant, no true engine temp indication.

[beyoko]

Mazdatech - I figured that out (but only after destroying the original sending unit trying to get it out). Thanks anyway.

I also found out that the sending unit is in the front Left (when facing the engine compartment) of the intake manifold, near the water inlet/thermostat housing. It's the one with only one wire running to the connector. There's another on the front right that has two wires running to it, but that's a sensor of some sort... not the temp sending unit.

Apparently the freeze plug install process calls for cleaning the inside surfaces of the block cavity (where the new plug will be installed) and coating the new freeze plug with a thin layer of RTV (silicone) sealant before installing. There's a special tool (freeze plug installer/remover) that is a long rod with a bend in it that accepts different sized "discs" that get centered into the freeze plug to ensure a "squared up" placement before tapping them into the block.

[mazdatech]

usually the temp unit with one wire is for the gauge only where as others with two or more wires are for the computer to read temperature.

[tm8frylok]

Take the wirer from the sending unit (w/ the enige off) and ground it.
Now start the car and let it idle, the gauge should move, it so then the problem is the sending unit. I am have the same problem on my 84.