Temp gauge not working Chevy C15

[TCLARK]

I am now trying to get the temp gauge working. The sender seems ok
it tested 900 ohms cold and about 200 ohms at engine operating temp.

I am not sure if I have the power on the proper side of the gauge, in
the pic I am pointing to the terminal that would go the sender.
When I shorted that sender wire out the needle should deflect to hot.
It does not. im wondering if I should put the power on the left terminal and the sender on the right??

I can abandon this and order a new bolt in gauge thats non electrical
but fun to tinker with this. I know the gauge worked on the bench before
I installed the cluster . All grounds are good ,I even took the gauge off
and tested the fine wire inside and it was grounded,also there is 6.7 volts
going to the gauge, the fuel gauge works perfectly.
Cheers
Terry .

[Frank v R]

send me a photo of the gauge , I may have a NOS one,

[Phil Waterman]

Hi Terry

Recheck the ground from instrument to body and engine to body. I've had problems where the gauge worked on the test stand and didn't in the truck, what it tracked out to was new paint on chassis and body made for a poor ground continuity, strangely the engine would crank. I've added an extra braided ground strap from engine to frame bolt that the battery connects to.

As a check how about a clip lead from the base of the sender to the instrument panel back.

Cheers Phil

[cletrac (RIP)]

All my Chevs use the bourdin tube gauge with the bulb on the end of the tube.

[TCLARK]

Originally Posted by cletrac

All my Chevs use the bourdin tube gauge with the bulb on the end of the tube.

Maybe my dash is a civilian??

[Grant Bowker]

I have definitely seen Bourdon tube temperature gauges in civilian Chevrolets. I had always though it was a function of model year. Pre-war and wartime mechanical gauges and changing to electrical about the time they went to 12V, about 1955 (but not sure the two changes are linked).

[TCLARK]

Thanks Phil
I checked and cleaned that all good, the problem points
to the gauge, or mixed up wires to the gauge. I took pics of
the back of the dash before I took it apart and it was wired as I have
done, but it was not original wiring.

Frank, I dont know if the gauge will separate from the housing
probably should.

Cheers
Terry

[Frank v R]

yes the whole thing comes apart, I'll check and see what i have

[TCLARK]

I took the whole gauge right out and found an open between
a wire post and the inside frame, I scratched it up and used flux and a skinny
soldering gun and was able to lay some solder on the connection.
I reassembled and tested and now it deflects to full hot when I
ground the sender wire. Now to see what will happen when I get
the engine operating temp!

Thanks Phil and Frank I will see tommorrow if I can warm the engine
right up and get a reading. All 4 original gauges will be working then!
Cheers
Terry

PS Phil do you know how the wiper vacuum hose is plumbed thru the dash??