JD 2755 Tach Quit Operating

[Red Raider]

I have a JD 2755 Cab Tractor that I bought new in 1987. I am a weekend guy, and tractor has less than 1500-1800 hours. About 1-2 years ago, the tachometer quit working. Obviously, hour meter quit, too --- other gauges and lights outside the "circle" work fine. I want to get the tach and hour meter working. I know you can't diagnose from a distance, but what are the likely causes -- what is my progression of looking? Thanks.

 

[Tx Jim]

1st thing to check would be the magnetic pickup(AR96480) located on frt of engine and the wiring associated with it. It can be checked with a volt/ohm meter but I don't know the correct readingd

 

[Red Raider]

Thank you

 

[reichranch]

I also have a 2755 with a nonworking Tach and hour meter. I have replaced the Circuit Board under the dash on the right side for a starting issue and that fixed the starting but not the Tach. I replaced the Magnetic pickup shown above and that didn't do anything. Do you think I need to Speed-Hour meter AL56731. I have looked for any obvious loose wires or connections and cant seem to come up with anything. Not to say that I could be missing something. Thanks for the help.

 

[Tx Jim]

Have you checked the dash ground wire connections? There are several wiring harness ground connection locations.

 

[reichranch]

Thanks for the feed back I will print that wiring diagram off and make sure everything on my tractor is connected. Is there any way that I can test to confirm that I have power getting to my Tach from the Magnetic pickup? If I can't find a loose ground. John Deere shows a Speed-Hour meter AL56731 about $400 and a Hour Meter AL33164 about $250. Which one of these should I try?

 

[Tx Jim]

If I'm looking at the parts descriptions correctly and I think I am AL33164 is hour meter only & AL56731 is tachometer & hour meter

 

[reichranch]

From the way it looks to me AL56731 does not include the hour meter. It looks like you have to buy them separate. Do you know of any way to test that I am getting the right signal to the my Tach now?

 

[Tx Jim]

I think it's both of them. AL56731 Speed-Hour Meter - SPEED-HOUR METER This is what it states in JDparts.com Note what I outlined in red.