M929A2 Hour meter not functioning

[Jim832904]

M929A2 . Tachometer works. Hour meter does not. White connector with two leads behind tach housing not receiving power. Guessing that connector should have power when the engine runs to drive the hour meter. Need to know where to look. Is it fused? What is its basic source and path? Looks like it goes into a harness bundle pretty quick. one of the leads is marked 994. Thanks.

 

[WillWagner]

Normal hour meters work when ignition power is on, some do go through a sender that is used as a switch to only record actual run time in the oil rifle....oil pressure closes the switch to send power to the meter....Did you look in the TM section for the manual that works for your truck?

 

[M35A2-AZ]

I think the Tach and hour meter or one unit. The unit on the back on the Tach is a drive unit for the diag. port that is under the dash on the right side.
Not used if you do not have the test set for the trucks. drive unit p/n 20511338, nsn 6680012729204

 

[simp5782]

M929A2 . Tachometer works. Hour meter does not. White connector with two leads behind tach housing not receiving power. Guessing that connector should have power when the engine runs to drive the hour meter. Need to know where to look. Is it fused? What is its basic source and path? Looks like it goes into a harness bundle pretty quick. one of the leads is marked 994. Thanks.

Tachometer gauge is bad. Usually they click or tick when operating if the hour gauge gears are on their way out

 

[Jim832904]

Tachometer gauge is bad. Usually they click or tick when operating if the hour gauge gears are on their way out

Thanks to all for the replies. If the tach cable drives the tach as well as the hour meter, then I must have a problem in that hour meter drive train. Will now open the gauge housing to investigate.