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castrol · 07-10-2015, 07:26 AM

What would be the first issues to look for with a transmission gauge not reading?

I'm working my way down this list of broken things. HAHA.

Just looking for places to start on this one.

~Wade

DtBt · 07-10-2015, 10:57 AM

The first thing I would check is the single wire connection at the sender. The sender should be near the transmission output shaft with a crappy connector on a knobby looking terminal at the sender. While down there clean the terminal and connector and measure the resistance of the sender. The terminal on lead may need to be replaced. Mine is about 2Kohms at room temperature and goes down at temp increases. You can short the lead to ground to see if the gauge moves. A short should peg high and an open shout be at the low end.

castrol · 07-10-2015, 03:08 PM

Quote:

Originally Posted by DtBt

The first thing I would check is the single wire connection at the sender. The sender should be near the transmission output shaft with a crappy connector on a knobby looking terminal at the sender. While down there clean the terminal and connector and measure the resistance of the sender. The terminal on lead may need to be replaced. Mine is about 2Kohms at room temperature and goes down at temp increases. You can short the lead to ground to see if the gauge moves. A short should peg high and an open shout be at the low end.

I'll start there. Thanks!

castrol · 07-27-2015, 10:17 PM

Quote:

Originally Posted by DtBt

The first thing I would check is the single wire connection at the sender. The sender should be near the transmission output shaft with a crappy connector on a knobby looking terminal at the sender. While down there clean the terminal and connector and measure the resistance of the sender. The terminal on lead may need to be replaced. Mine is about 2Kohms at room temperature and goes down at temp increases. You can short the lead to ground to see if the gauge moves. A short should peg high and an open shout be at the low end.

Finally got to crawl around under there. I was greasing some zerts this afternoon and I remembered this post. So I looked around to see what I could find. Lo and behold, here's a single blue wire, kind of folded up out of the way. Hmm, that looks odd. It looks like it could possibly connect *click* here...

What do you know. Functioning temp gauge for the transmission now. Woot!

Vanwill · 07-29-2015, 11:14 AM

Quote:

Originally Posted by castrol

Finally got to crawl around under there. I was greasing some zerts this afternoon and I remembered this post. So I looked around to see what I could find. Lo and behold, here's a single blue wire, kind of folded up out of the way. Hmm, that looks odd. It looks like it could possibly connect *click* here...

What do you know. Functioning temp gauge for the transmission now. Woot!

Jim? I have a dozen CNC machine tools in my shop. ALL their controls are far beyond my electronic troubleshooting ability. But over 30 years, it has amazed me how many times I've been able to find the problem by doing nothing other than looking over the circuit boards carefully. Probably a dozen times I've seen a board-level component that had VISIBLY failed, and more often than that a connection that was loose or disconnected.

For years, I've always given any failed machine the "visual inspection" before calling Fanuc. And my trans temp gage?--EXACTLY the same problem as yours. Of course, an Allison or Cummins dealer could also have quickly (?) found the problem, but it would have cost you $250.

Good job!!

maxwell18 · 08-21-2015, 07:20 PM

I have a 2005 Diplomat, had a concern with low oil pressure, purchased a Silver Leaf system. Oil pressure gage was off aprox 45 percent. Also Trans temp was off. Bottom line buy Silver leaf.