The Combine Forum banner
1 - 2 of 2 Posts

· Registered
Joined
·
77 Posts
The DAM controller is bolted to the left side of the grain tank. Open the door on the left side of the machine at the top of the steps, were you check hydraulic oil. There are two self tapping screws that hold it to the grain tank wall. As for the digital display its a self contained system. Power and ground in and leads to the four speed sensors. I have the service manual in the shop, will take a look tomorrow and post back. I know Deere wants close to a grand for a rebuilt one. All States Ag Parts has rebuilt ones for about half.
 

· Registered
Joined
·
77 Posts
I took a look at the service manual. There are only two pages on the tach. There is a test for the display segments in the digital display and a Deere special tool test for accuracy. If one or more sections are giving no RPM reading it would be wiring to or a sensor. Yours sounds like a bad unit tho. No mention of flashing display or all lights lit up. There are four switches under a round plug in back that set the calibration for your tire size and final ratio. If you replace make sure your new unit's switches are in the same position as the old one. There is a six prong plug in the rear. On the face of the plug there is a number beside each terminal. No.6 white wire is the ground and should have no resistance when checked with a ohm meter. The cigarette lighter, hour-meter and a few other things use the same ground circuit. No.5 purple wire is the hot wire from the ignition switch and should have battery voltage with key on. The other four wires go to the sensors. If the ground circuit and power circuit check out I would say you have a bad tach unit. You can PM me and I can scan and email you the pages if you want. Look at it this way at least the 20 series only have three spendy electronic box's compared to the dozen or more on the newer ones. BTW you can Google the PN. AH99763. Its the PN for the tach and there is another company that rebuilds display units.
 
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top