New Holland Temp Gage ???

[HGLENT]

I am a new member to this list with a New Holland TC33D tractor which I have owned since new. I do all of my own maintenance work, seldom taking anything to a shop. I have run into a problem I can not figure out.

The Temp Gage stopped working. I checked the wiring and found the wiring was okay. I ordered a replacement Temp Sender and installed it. The new sensor did not fix the problem. I ordered a replacement meter for the cluster. Again it appeared not to solve the problem.

After several hours of use I noticed the needle had move a little off the peg, and dropped to the peg when the key was turned off. So I concluded the circuit is "kind of" working.

Has any one run into this issue? What could the fix be? Also, does anyone have a schematic diagram of the circuitry in the instrument cluster?

Paul K
HGLENT

 

[jinman]

Temperature gage problems on the New Holland compacts can be frustrating. Fortunately, there is an easy way to check the gage and wiring all the way from the temperature sending probe. Remove the wire going to the probe and use an alligator clip jumper or other suitable wire to connect the wire you disconnected to ground. If you use an alligator clip, you can clip one end of the jumper onto the wire and the other onto a bolt or bare metal such as the body of the alternator. With the wire grounded, go turn on your key switch. The temperature gage should go all the way up to maximum temperature. If it does, just turn the key off and reconnect your wire to the temperature probe.

The temperature probe is a resistor that decreases resistance when it heats up. By grounding the wire, you are simulating the highest temperature in the probe and the gage should go all the way to hot.

Checking the temperature probe is a bit harder, but since you replaced it with a new one, I think you have to assume it is good.

Finally, your tractor sounds to me like it has the stuck thermostat problem. The thermostats on our tractors are a poor design. They have a little valve that is supposed to relieve air pressure within the system. That little valve can move out of proper position and jam the thermostat open. When that happens, your engine never heats up. It runs far below the normal operating range and that seems to be what your gage is showing. The thermostat is right where the radiator hose comes out of the engine. There are two bolts to remove the adapter where the hose is clamped. The thermostat is inside that adapter. You will probably need a gasket or a tube of liquid gasket maker handy. If you remove the thermostat, be sure and notice which way it is installed. If you reinstall it backwards, your tractor will overheat. Most likely you will see the problem as soon as you remove the adapter. The thermostat does not have to be open very much to keep your engine from heating up.

Good luck with your repair. This type question is best to be asked in the New Holland Owning/Operating forum because more NH owners are likely to see it. It is okay that it is here, but you might have more responses in the other forum.

 

[HGLENT]

Excellent call!!!

Thermostat looked exactly like picture, and test as stated. I put it all back together, and it is sitting out there running perfectly with the proper indication.

Thanks a bunch for the help.

Paul K.
HGLENT

 

[jinman]

:thumbsup::thumbsup::thumbsup:

 

[Waltonator1959]

Same problem here on a TN65. Great tip on checking the wiring jinman. It all checked good. I’m assuming changing out the probe is the next step. Any thoughts?
Thanks