That's what is called a capillary type sending unit does not need external power. Take it out of the block and boil some water in a coffee cup stick the probe(only) in the water meter should start to rise(will take a short period of time). Tested one like this for my dad. The probe tip needs to be completely immerssed in the water. Will not work right if the probe when installed is touching/hitting other parts, i.e. need to have coolant all around it. Have one installed on my truck now it is not mounted exactlly like the original there is an adapter between the probe(male) threads and block(female) threads. this has the probe sticking off the block about and inch. Hope I've helped.
------------------
1970 GMC K25 Custom
Chesapeake, VA
My 70 GMCor Webshots http://community.webshots.com/user/70gmc
__________________
1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs
1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX
1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears
1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now.....
1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone.
1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed.
1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm 
|