4530 TEMP GAUGE PROBLEM

Srb08 · Oct 16, 2012

I have a three month old 4530. Since new, the temp gauge has not worked. The sensor and gauge cluster have both been replaced. The continuity of the wire has been verified. The dealer is out of ideas. This afternoon, I ran the tractor for 30 minutes moving logs. After I was finished, I opened the hood and felt the radiator. The radiator was hot but not hot enough to burn my hand. I didn't have my infrared temp gun to check temp but I could hold my hand on the radiator for 3-4 seconds before it became uncomfortable.
I'm wondering if maybe the thermostat is either stuck open or missing completely.
Any ideas?

Thanks,
Steve

Oldtractorfixer · Oct 16, 2012

Sounds like you need to verify temp in radiator. Carefully open the cap check the temp with your gun. If you had to remove your hand that quickly it was probably over 100 deg. I would think your gauge should show something. Most gauges use a variable resistance sender a connection to the gauge and a power source and ground for system. Got to go back to the basics.

Srb08 · Oct 16, 2012

I was also going to verify that I have voltage on the input to the sensor as well as ground continuity through the sensor body to the frame.
Like you said, it's gotta be something simple, this is not a complex circuit.
Unfortunately, the service manual only tells you to replace the two components that have been replaced. There are no useful schematics or electrical values for the electrical system. I was very disappointed in how poorly the manuals are written, at least the electrical portion.

Oldtractorfixer · Oct 17, 2012

The sensor is usually on the "ground" side of the curcuit. Power to gauge other side of gauge to sender other side of sender to ground. It can also go the other way. Try grounding the wire from the gauge at the sender. The gauge should go to full hot. You can also bypass wiring for testing.

Any chance it has two senders and they replaced he wrong one? Possibly one for gauge and one light or other system?

Good Luck.

OldGinTractors · Oct 18, 2012

There are 2 sensors. One for the temp gauge and another for the KSB injection timing. Sounds like the one for the temp gauge might not be connected.

Dave

Srb08 · Oct 20, 2012

The problem was the gauge cluster. The dealer failed to reconnect the lead at the sensor after testing everything and replacing the gauge cluster.
I went out this morning to verify the voltage on the sensor lead. Opened the hood and saw the lead hanging there. Connected it to the sensor, started the tractor and just like magic, it worked.
Never underestimate the power of continuity.
Thanks for the feedback, you were right.
Best,
Steve