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]

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??

[Frank v R]

I checked stock and I do not have any temp gauges but I do have fuel and oil and speedos all NOS

[TCLARK]

Awesome Frank, that is so good to know, after I get the wipers up and running
I am tackling the speedo.
Do you happen to have a speedo cable or know where to get one.
I really need the outer part and I can probably put a new cable
inside!
Cheers
Terry

[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]

I am having trouble finding a sending unit for a early forties
gm truck.
Maybe my electric gauge is later manufacture altough it
does fit in the 1939-1946 gauge unit.
Terry

[Bruce Parker (RIP)]

Originally Posted by TCLARK

I am having trouble finding a sending unit for a early forties
gm truck.
Maybe my electric gauge is later manufacture altough it
does fit in the 1939-1946 gauge unit.
Terry

I'm also having trouble finding a GM/Chev electric temp sending unit, though in my case it's for a 12V system. I have tried a number of units for the block that look right and are NOS but don't work. My best guess is that they are designed for a dash warning lamp that is either 'off' or 'on' based on a predetermined temperature. What I need as a variable sending unit to read on the gauge. Any ideas?

[TCLARK]

Bruce, I don't think you should have much problem finding
a 12v sender. The sender should only have a single pole
and possibly be a TS-6. I have seen them on the internet
for 12v systems. I ve read that these are tested by
measuring resistance at different temperatures, by putting
them in hot water and cold water.
Terry

[Bob Carriere]

I am using a NOS GMC rectangular civilian pattern

I t came with a mechanical "bourdon" tube and greatly simplify my chabig to 12V.

Oil gauge is mechanical and works But has now been replace with a larger face circular oil pressure gauge mounted under the dash...... I wanted more info to monitor.... installation may be reversed at a later time.

Fuel gauge needed a voltage reducer to use with the my 12 v system........and with the two way fuel tank switch from Bob Phillips worked beasutifully. Both floats were replaced with repro.

I now have 237 miles on the odometer.

For the Speedo...... because I was using a GMC the fitting at the speedo head is a hollow square and had to have a cable made....... found a guys who works from home near Smiths Fall who for just under $100 made me a cable that fits the GMC head and the GM T case fitting..... steel with black vinyl coating...... bare steel sheath is also available but shunned due to rust deterioration...... he does a lot of antique boat tachometer and strongly recommends vinyl coating for all applications. Mine went on flawlessly.

That leaves the AMP meter which can be used as is even with voltage changes as it functions basically as a master connection for all other items that are going through it........ it basically shows if the charging system is putting out enough voltage / amps to satisfy the demand and with a a 75 amp alternator should never be an issue with a stock CMP......

My various toggle switches are all PA after finding that the NOS, still wrapped and sealed toggle switches, had badly oxidized inside the wrapping.

If you are curious, Ebay had a few listings for rebuilt Chev clusters just short of $1000 USA DOLLARS.....HO BUT WITH FREEE SHIPPING hA!!!
\
CHEERS

[TCLARK]

Hi Bob
I was almost ready to buy a new dash board but since the
other gauges work, I will pursue this temp gauge rehab.
I found on the net that I need a AC Delco 1512015 sender
which is used on 6v. gm vehicles. There is one on ebay
for 135 US but I may find one around here even on an
old grain truck. I have a friend who is a electrical
engineer who may know how to adjust the present set up.

I am also working on the wipers, do you know how the vac line is
plumbed thru the dash, see my pic earlier in this thread.
Speedo cable is next, thanks for your speedo info!!

Thanks
Terry

[Frank v R]

Terry, I have NOS speedo cables , they are for the G-506 Chevy, you'll need to give me a length,

[Bob Carriere]

Hi Frank

Can you post a picture of the connector for the speedo and the overall lenght.

Thanks.....

[Bob Carriere]

Hi Terry

ON the cab 11 the solid copper line comes out centered on the dash.....on the cab 12....with the windshield that opens.... it comes out the driver's side on the rigid post than transition via a short rubber line to the solid line of the wiper motor mounted and pivitting with the windshield...... T connection to the other wiper motor.

I only have a cab 11 pic at the moment but can look for or take pictures of a cab 12 if needed.

Cheers
PS plumbing done by Grant..... with acorn nuts as they are less damaging than a bare nut/bolt staring at your forehead.

Notice the absence of door hooks/eyelets.... mine never had them retro fitted.

[TCLARK]

Hi Bob
So my Cab 12 has a non opening windshield, but no hole for the
copper line, so should I route it over to the drivers windshield post?
Were will it go thru on the drivers post?

Good idea to look at the speedo ends, do you know the length I need?

Mine could be a civilian dash and speedo, since the temp gauge is
not capillary type.
Cheers
Terry

[Bob Carriere]

HI Terry

Will need to take pcitures of my best cab 12 for the vacuum line.... I know where it is from memory but a picture is worth a 1000 words.

Temp gauges I have seen of those civilian dashes ARE all with the copper line none were ever electric....but then I have lead a seclude life.

Lenght is approx. 84 inches on mine which was copied from an old original.....

The trick is where it connects to the T case.

The speedo cable is driven by the center gear..... center cap of the T case.
Ther are two models..... the better ones the connection on the cap where the cable screws in is at 9 oclock when sitting underneath and looking back. So the cable comes down within the frame over youleft shoulder end goes into the t case center cap with a minimum of bending.

ON the worst model the connection is at noon and requires a sharp 90 degree bend to connect into the T case......... cable do not like to be bent that way..... some models had a piece of sheet metal that was clipped to the cable housing that held the sharp bend stable........ The Original cable for the GMC trucks that Frank sells do have that metal reinforcement for the sharp bend at the speedo head.

For simplicity I found and transplanted the 9 oclock cover from another T case for my truck.

Pics tomorrow

Cheers

[Bob Carriere]

Missed that........

You mean you have no brackets on each side to open the windshield.......

The all you need to do is look for a hole in the centre of the dash just below the windshield frame...... or make one....... look at mine...the copper line fits right in there with the rubber tube inside the engine compartment.

Must have been made on a late Friday afternoon with whatever parts where available..... maybe you got a cab 11.5

Cheers

[TCLARK]

Hi Bob
Nope the window won't open and no roof hatch, probably built
on April fools day!
There has never been a hole in dash center for the vac line,
but I can soon make one. Tomorrow I'm going to have a good look to
see where that line originally went. Maybe it had no optional wipers too ha ha.
I did rebuild the wiper motors and they purr along nicely. I used fluid film
instead of petroleum based lube, so the seals shouldn't deterierate too badly.

Sure hope I can get an original speedo cable!
Cheers
Terry

[Phil Waterman]

Hi Guys

Take a look over by the right hand winshield post, that is where the line was
on my Pat 12 C60L. Take a look at the pictures on http://canadianmilitarypattern.com/C...Windscreen.htm I'll try and find some better pictures on main computer and post them later.

Cheers Phil

[TCLARK]

Hi Phil
Your right I can see line making a bend on the post. I am going out
to see if I have a drilled out hole on that side! Since
my windshield is non opening, I may take Bobs advise and drill
near the center. I'm puzzled because I have the original T with
tubing(I think original) that I have mounted but no hole.
Was this truck bought at Walmart? Ha ha
Cheers
Terry

[Phil Waterman]

Hi Terry

The center would make more sense it would be nearest the vacuum port on the manifold. If there is a hole near the windshield post but has the T in the middle then I might suspect that the windshield frame had been swapped at some point. It is not a very strong design.

Cheers Phil

[Grant Bowker]

Bob and I looked at one of his Cab12s today. Phil's statement about tube attached to right pillar matches that truck. The T fitting was located just inboard of the right wiper motor. Check to see if there is evidence of a centre hole being welded over as Bob's 12 had both holes with tube at right and centre welded (brazed?) over. Photos to follow.

[Bob Carriere]

Freezing rain here most of the day and still raining...... workingon the computer in between short power outages....... should freeze hard my tomorrow evening if not sooner.......

Cheers

[TCLARK]

No evidence of holes anywhere, not even welded over,I
think I will plumb the tube down the center as suggested.
I should visit the sister truck about 45 minutes east, and have a look;
I would also like to see if it has capillary tube or electric
heat gauge. The truck is identical to mine but is for parts only.
The owner wants me to buy it but there is nothing I really need
on it other than an inside door handle!

I will post a pic of a Ford
wiper plumbing, taken at an old farm junkyard in S.Alta.
Cheers
Terry

[Tony Smith]

Originally Posted by Bob Carriere

If you are curious, Ebay had a few listings for rebuilt Chev clusters just short of $1000 USA DOLLARS.....HO BUT WITH FREEE SHIPPING hA!!!
\
CHEERS

Also seen this, which although a reprint, might save you from buying a US$1000 cluster!:

http://www.ebay.com/itm/AC-GM-Instru...1YBVMr&vxp=mtr