How is it possible for this temp gage to work?

I bought the tractor like this and it has just one wire from gage going to sensor. It doesn't work and it doesn't make any sense how it could work with no battery power.

There is a working fluid in the tube, (not a wire) that expands and contracts as heated. The gauge has a Bourdon Tube in it that bends under hydraulic pressure from the sending bulb in the engine block. All mechanical. Jim

its very possible! its not an electrical gauge. it works with the bulb in the coolant, by the coolant warming the bulb. no battery needed. thats the way temp gauges were before the beginning of time. most likely need another gauge. its 30's , 40's 50's and 60's technology and work very well.

The working fluid is often a hydrocarbon like ether or other fluid that has a transition point to allow expansion when hot and contraction when cold. The Bourdon tube needs to be looked up as it is rather simple to understand but complex to explain. Jim
one article.

It has an electrical connection, but maybe someone was an idiot! I cut it trying to get the original electric gage to work but it's a solid ground.

I've always preferred that type of gage. Only thing you need power for is to run the light. Probably more accurate too.

no such thing unless that is the wire for a light.

show where that wire is going just a wire pic means nothing.

and also once that lead wire gets damaged or cut that gauge will not work. its junk, want to test it put it in a pot of boiling water on the stove, once you get it disconnected form the head, if needle dont move its scrap.

This post was edited by DoubleO7 on 07/08/2023 at 05:25 pm.

That may be the power wire to the gauge light if there was one in the socket.

If the gauge is mounted in a non metal panel, it could be a ground wire to one gauge mounting stud in order to get the light to work.

That wire is the only wire coming out of gage and I'm positive it goes out by motor and has a electrical connection splice.

It's a wet gauge rather than an electric gauge no electric needed. If you cut the main tube you now need a new gauge. None better than those wet gauges for simplicity and working.

If that line was cut, it can't be fixed with electrical connections. The whole unit from the dash into the engine has to be replaced.

(quoted from post at 18:25:06 07/08/23) That wire is the only wire coming out of gage and I'm positive it goes out by motor and has a electrical connection splice.

Click to expand...

All that is nice but it still doesn't convert it to an electric gauge.

Start at the gauge, shown in your picture, and follow the ''wire'' (as you choose to call it) to where it connects into the engine in your other picture. Loosen and remove the outer hex nut (likely need a 5/8'' wrench) then pull the end out of the fitting still threaded into the engine. It will have a bulb on it. That bulb held the fluid that expanded and made the Borden tube, inside the gauge, flex and move the needle. If the tube was cut and has the ''electrical splice'', it was ruined. (Yes, some people have repaired these gauges, but I don't see that it is feasible or economical in most cases.) Looking at the cut ends of the tubing it would appear to be a solid wire as the diameter of the hole in the tube is small and the cutters would have pinched it shut. If the electrical splice is in the tube between the gauge and the bulb in the engine, you summed it up in your post where you posted; ''It has an electrical connection, but maybe someone was an idiot!''.

What Tractor is this on? The 1486 you posted about on the Farmall & IH Forum where wore out posted a wiring diagram for you? That diagram does show an electric gauge which would have been in a panel, not a stand-alone gauge you posted a picture of. Are you trying to get the original gauge (electric) located in the gauge panel to work? If so, this mechanical gauge has nothing related to that gauge.

If this is on a 1486 with an electric gauge panel, a stand-alone gauge like you posted would be something someone added if the original gauge in the panel stopped working. The added gauge, in your picture, has no connection to or need for the original electrical temperature gauge wiring. This video may help you understand.

A Mechanical Temperature Gauge Video

If this gauge panel is related to this thread, the coolant gauge shown here, from your other post, and the tube for the add-on temperature gauge, shown in this thread, have no relationship whatsoever. The original coolant gauge, in this picture, used wires and an electrical sensor/sending unit to get temperature info from the engine to the gauge. I don't know where they mounted the electric senders in those engines, so can tell you if it was where the mechanical gauge's bulb is now, or if it is still in the engine at a different location. I can tell you that nothing you do to that capillary tube for the add-on gauge with electrical wire splices, will make this electric gauge work. They are completely different types of gauges.

Yes it is the 1486, the original gauge
does move but I'm not sure if it will be
accurate it seems to want to move all the
way to right easily but may be screwed up
wiring from all the farmer fixing done on
it and I would need a new sending unit.
The add on is prabably mechanical but it
for sure had an electrical splice by the
engine so it must of been an idiot. But I
thought mechanical gages usually had coil
around it so it can turn gage, how can the
wire turn if it's tight in the plastic
coating?

(quoted from post at 19:16:13 07/08/23)

Click to expand...

the cylinder with the slot in it above where the tube joins the back of the gauge looks like a bulb socket. the wire u mistakenly cut is likely associated with that.

as others have said, it's unrelated to why this gauge is not working. it's related to why it won't light up

This post was edited by HFJ on 07/09/2023 at 08:34 am.