B7610 intermittent trouble starting

[Tim_in_IA]

Hey guys, every once in a while the B7610 wont start. It wont turn over. I can start it by turning the key on and then shorting the terminals on the starter. Other times it starts fine. Is there some electrical component between the key and the starter that would be doing this? I would think if it was a sensor that it wouldn't keep running after I shorted it.

 

[d1king]

Following comes up under 'b2400 not starting'. I had similiar problem, installed the kit and have had no other concerns, appears to be a result of cumulative voltage drop. There are also other possible concerns with safety switches, but if it finally starts then I'd look at this post real close. Good Luck.


Since last summer, when I tried to start the tractor, most times it would take up to 10 or so tries turning the ignition key on and off to finally start. With each try, I could hear the starter solenoid click. I cleaned the battery terminals, battery clamps, and ground connection to the frame. Problem not fixed. I then replaced the starter solenoid and that didn't fix the problem. Since I needed the tractor to start without fail for winter snow blowing, I had the Kubota dealer pick it up for repair. He replaced the starter switch and it started OK all winter. This spring, the problem started again. When I used jumper cables to start it, it would start OK. I assumed the 8 year old battery was bad so I replaced it. Problem not solved. I then temporarily installed new battery cables. Problem still not solved. Finally I read Kubmech 's posting on this problem (7/15/04). He explained that the increased resistance in starting circuit as the parts aged caused a decreased voltage to reach the starter solenoid. When this voltage decreased enough, the solenoid did not have enough current to engage. His solution was to install a low voltage relay which would engage and allow full voltage from the battery to engage the starter solenoid. Use of John Deere part AM107421 was recommended (Approx $18). Since I had tried almost everything else (and didn't want to have to send the tractor back to the dealer) I bought the part and installed it. Tractor had sat for about a week and started on first try. The part has been installed for over a week and the tractor has not failed to start on the first try. Installation is easy, it is almost as if this part was made for installation on a Kubota. Wires from low voltage relay plug right into the Kubota solenoid terminals and wire from ignition switch. (See Kubmech 's posting for detailed installation instructions). If you have this starting problem and cleaning the battery cable clamps, ground, battery terminals and your battery is good, I would suggest trying this part. The most you can be out is about $20. Wish I had read this posting earlier, it would have saved me about $350. Thank you Kubmech

 

[KubieTwo]

Hey guys, every once in a while the B7610 wont start. It wont turn over. I can start it by ----turning the key on and then shorting the terminals on the starter---. Other times it starts fine. Is there some electrical component between the key and the starter that would be doing this? I would think if it was a sensor that it wouldn't keep running after I shorted it.

Safety switches are "between the key and the starter" and any one of three failed, out of adjustment, or inappropriately positioned can create what your are experiencing. One of the following would be my guess...

...Most likely is HST pedal safety switch. Try rocking forward/reverse while turning switch to start position

...next most likely is pto safety switch ...lever bumped to activate swithc

If the fuel solenoid is powered and open, that it all it needs to run and it starts because you have jumped the starter circuit, so is probably one of the three safety switches. The third is the seat switch which could be out of adjustment or faulty, but the other two are more frequent causes.

Good luck

 

[Tim_in_IA]

thanks guys! I figured if it was a safety switch that it wouldn't let me start it at all. The low voltage thing sounds interesting. One note is that it has gotten real humid and it does sit outside. I had the seat tipped forward to keep rain off but this also exposed the 2 seat switches so they could be suspect. I did think they were as I disconnected them and shorted them to see if it would start and it didn't. All of the suggestions are great.

 

[d1king]

Tim, believe somewhere in that thread on 'b2400 not starting' there is a diagram on how the low voltage relay hooks up. If you can not find it and you want to try one from the auto parts store, pm me with a fax no. and I will try to fax it to you,think I have the instructions still that came with the kit out at the farm. Auto store part is a lot less expensive to try, I just liked the kit because it came with wires color coded etc. Easier to hook up, no brainer even for me. Good Luck, Don