Instrument Gauges Gone Awry

[rnds76b]

2008 Mahindra 4110 diesel tractor. Recently noticed that my engine oil temp needle was registering between the bottom and first mark on the gauge. Normally registers at the 1/2 way point on the gauge (third mark). Then noticed that my RPM needle wouldn't go above 15, when it's normally 25 + when running the tractor at higher speed, or when using my PTO woodchipper. Then noticed that after I filled the fuel tank, the gauge was only registering 3/4 full. All the lights on the instrument cluster (glow plug, PTO, blinkers, etc.) work fine. It seems to be ONLY the Fuel, RPM and Temp gauges that are not registering properly. Have check all fuses in the firewall fuse box. Have check all the connections to the instrument panel (unplugged them, blew them out with compressed air and reattached them), and all the connections between the battery and the cluster. All connectors checked and good...no broken/frayed wires. Seems VERY odd that all three gauges would stop reading accurately at the same time. Figuring there's gotta be some common denominator. Heard somewhere that the alternator could cause such things..anyone else heard/know that? Also, anyone know how to test the instrument cluster? It'd have to be the third grade version for me... Am checking with Mahindra dealer in area, but don't expect much other than, "Buy a new cluster." Any help greatly appreciated. Other than the gauges not reading properly, the tractor starts and runs fine.

 

[duffer]

My neighbor just bought a 2019 model 2638. Original owner told him his fuel guage wasn't working. Dealer put in a new sending unit. Didn't fix the problem. Had to get a new instrument cluster. By the time the part came in the tractor was out of bumper to bumper warranty. Cost the guy $1000 for the instrument cluster....so beware.

I'd check for proper grounding wire(s) from the cluster, varments chewing thru wires, etc. If the sending units were bad, I doubt if the guages would work at all.

Just my 2¢

 

[rnds76b]

Thanks Duffer...your comments renew my intent to re-trace all the wires.

 

[DaBear3428]

sounds like a bad ground connection.

 

[Sergei1]

You might try running a separate ground wire and bypass the original one, since it's affecting different gauges. My tractor has those gauges connected to the same ground point, so it sounds like it could be a wire or connector with corrosion causing high a resistance.

 

[rnds76b]

Thanks guys...good idea...will run a separate ground soon & let ya know....

 

[michaelbuck]

Yes grounds are extremely important and without having used your tractor in last 24 hrs and have not charged it what is the resting voltage of your battery. Should rest at 12.78V if its 12.50 or lower your 50% charged. then with tractor running what is voltage across battery. Should be minimum 13.5 volts and no more than 14volts

 

[michaelbuck]

Forgot to say I have the Mahindra 2638 HST and love it. I have used it without fail and it runs perfect.

 

[rnds76b]

2008 Mahindra 4110 diesel tractor. Recently noticed that my engine oil temp needle was registering between the bottom and first mark on the gauge. Normally registers at the 1/2 way point on the gauge (third mark). Then noticed that my RPM needle wouldn't go above 15, when it's normally 25 + when running the tractor at higher speed, or when using my PTO woodchipper. Then noticed that after I filled the fuel tank, the gauge was only registering 3/4 full. All the lights on the instrument cluster (glow plug, PTO, blinkers, etc.) work fine. It seems to be ONLY the Fuel, RPM and Temp gauges that are not registering properly. Have check all fuses in the firewall fuse box. Have check all the connections to the instrument panel (unplugged them, blew them out with compressed air and reattached them), and all the connections between the battery and the cluster. All connectors checked and good...no broken/frayed wires. Seems VERY odd that all three gauges would stop reading accurately at the same time. Figuring there's gotta be some common denominator. Heard somewhere that the alternator could cause such things..anyone else heard/know that? Also, anyone know how to test the instrument cluster? It'd have to be the third grade version for me... Am checking with Mahindra dealer in area, but don't expect much other than, "Buy a new cluster." Any help greatly appreciated. Other than the gauges not reading properly, the tractor starts and runs fine.

Everyone...thanks so much for the input & suggestions! Unbelievably, over the past few months, the instruments I spoke of that were not reading correctly, have gradually returned to almost normal. Qs you've all indicated, I'm fairly certain it's a grounding problem...just haven't had the time to delve into it much...will do it one day soon...thanks again to all !!!!!

 

[Straightgrain3016]

My guess...