JD 970 cut off while mowing

[RinggoldDan]

Hi,

I have an 1989 Deere 970 compact utility tractor that just stopped running while mowing last weekend. The tracter cut off just like the key had been turned off. When trying to start it, the dash lights come on sometimes, are dim sometimes and sometimes just are not on at all. When the lights are on bright, it is possible to try and start the tractor but there is a click and then nothing.

Have put another battery in and tried but no different behavior. Checked the voltage at battery - good, from positive of batter to frame - good, from positive of starter to frame - good. Have disconnected and replugged all solenoids I could see and checked all (8) fuses. The seat safety switch has been disabled for many years (did not know Dad had done that so I will be replacing that soon).

when the lights are on and I attempt to start it, the voltage drops from good (12.+) to nothing from starter positive to frame ground. If leaving the switch on, there is frequent clicking and dash lights may come on and then go off.

Similar happened many years ago but unfortunately, Dad is not around to ask anymore - might be why the seat switch was bypassed.

Any clues to start looking into?

Thanks,
DW

 

[JimRB]

13 volts is good. 12 volts is actually about dead. 2.2 volts per cell times 6 cells. No way to get jumper cables on it and a running vehicle?

Have you cleaned the ground where it bolts to the fame? Last battery change I did that bolt and lug was corroded. You might try running a jumper cable from the ground on the battery to another place on the tractor.

 

[JimRB]

Frame. On my 870 the ground is easy enough to get to when the battery is removed.

 

[MNchipmaker]

Assuming you have a gasoline engine I suspect that the root cause of your problem is a charging system failure. That would explain the unexpected shut down. I would proceed as follows 1) Recharge the battery with a wall charger. 2) Assuming the tractor starts after charging the battery then trouble shoot the charging system.

 

[joecdeere]

+1 for bad ground

 

[mfreund]

Bad batteries.

 

[chriswheeler]

Sure could be the ground and or the ground cable, could be a short as well. I'd first try a known good battery and clean and check both cables. I have the original cables in my 92, but have lost the ends on them and had to replace the cable ends. Before starting, turn on all lights, see how bright they are and shut them off before trying to start it. Could also be the key switch shorting internally, but I'd expect to see some blown fuses with that. Remember, with this diesel there is a fuel shut off solenoid and you must have power enough to it to activate it to get fuel to the pump. Pull the grill, clean and check all battery terminals, change to a known good battery, give it a go. If you didn't know, grill on these is on springs and folds out from the top below the headlights, disconnect the 2 springs, much better access than working from the top. My 970 has worked out to be a reliable machine.
Chris