B7610 No Start

[Buckeyeman]

I have an intermittent problem with my B7610. I warm up the glow plugs upon starting and turn the key and it starts and shuts off right away. Other times it starts and stays running. When it doesn't stay running, I bang on the top of the instrument panel with my hand and it starts and runs. What is inside of the panel that could be going bad?

Thanks in advance.

 

[the8080]

I have an intermittent problem with my B7610. I warm up the glow plugs upon starting and turn the key and it starts and shuts off right away. Other times it starts and stays running. When it doesn't stay running, I bang on the top of the instrument panel with my hand and it starts and runs. What is inside of the panel that could be going bad?

Thanks in advance.

I'll assume your tractor normally shuts off when you shut off the key, you don't pull a shut off knob to stop the motor. In that case you have a fuel shutoff solenoid under the dash or hood. On my L35 there is also a Key Switch Timer Relay which is under the dash. When you turn on the ignition, the relay turns on which energizes the solenoid, opens the fuel shutoff and allows fuel to flow to the injection pump. When you turn the ignition off, it closes the fuel shutoff valve and stops the motor. The relay is the first thing I would look at. It may be hanging up intermittently, the wiring between it and the ignition switch may be a problem or the ignition switch itself may be a problem. It could also be the solenoid or a wiring problem to it.

 

[DennisArrow]

Now the question is how to get the shroud off around the dash and instruments. I asked this a couple of years ago and got zero responses...........ANY thoughts would be great ............God bless......Dennis

 

[the8080]

Try to look at the "illustrated parts list" (Kubota Tractor Corporation - Parts) on the Kubota web site. It looks like you just remove the screw in the top of the shroud and slide it up. The bottom looks like it is just a couple of tabs that slide down into brackets on the sheet metal. Probably have to worry about wires and the speedo cable after it is loose. A quick look at the parts diagrams show a relay under there but doesn't say what it is for. Your stop solenoid is on the top front of the motor somewhere.

 

[Buckeyeman]

This page is out of the service manual. Is it #3 or #4 that could be bad?

 

[the8080]

I'd suspect 3 first. It is under the dash where you are banging and relays are always suspect because their contacts wear and can get stuck. If you get in there, unplug and plug back in all connections in the circuit. Since it is intermittent and responds to your banging, it may be just a poor connection from a little corrosion. The connection from 8 to 3 brings up another possibility of failure mode. 8 generally must be working or it wouldn't allow you to crank but that one connection might be bad. You would need to get a meter on it to see.

 

[Buckeyeman]

Now the question is how to get the shroud off around the dash and instruments. I asked this a couple of years ago and got zero responses...........ANY thoughts would be great ............God bless......Dennis

I second this. The workshop manual does not show you how to remove the instrument cluster to check anything.

 

[Buckeyeman]

After figuring out how to remove the instrument panel, I noticed a lot of dirt and some grass clipping behind it. I cleaned everything up and discovered that the terminals on the Key Stop Relay was dirty and now it starts. I ordered a new relay for a spare just in case. Thanks the8080 for your help narrowing it down.

 

[DennisArrow]

Thanks 8080.........Where in N. Ga????...........Will try what you suggest in the next couple of days and get back on here......Yes, I already looked at the parts drawing from Messicks............Anyway....thanks again and have a great Christmas...........God bless.......Dennis

 

[Buckeyeman]

Well after almost a month of running fine, I go out to plow snow last night and the tractor shuts off as soon as you turn on the headlight switch. Go figure? If you leave the headlight switch off it runs fine. I looked at the wiring diagrams and it looks like there is a wire that comes from the Main Switch that supplies power to the headlight switch. Should I replace the headlight switch?

 

[Mendonsy]

That sounds a lot like there is a bad connection somewhere. The additional current draw from the headlights may be causing the voltage to drop too low to keep the fuel solenoid on.

 

[the8080]

Unplug both head lights and see if you still have the problem. If yes, problem is in switch or wiring. Maybe wire rubbed bare and causing partial short? Bad switch? If it is like mine, round with lever on side for flashers, it is pretty easy to take apart and clean up contacts, check for broken parts.

If no problem, plug headlights in one at time. If problem comes back with only on or the other light plugged in, problem is with that bulb or wiring to it. If problem comes back with either or both plugged in, you are back to chasing the switch or wiring.

Any snow/ice packed in behind the dash or around the headlights? Good luck, surprised it didn't just blow a fuse.

 

[Buckeyeman]

Unplug both head lights and see if you still have the problem. If yes, problem is in switch or wiring. Maybe wire rubbed bare and causing partial short? Bad switch? If it is like mine, round with lever on side for flashers, it is pretty easy to take apart and clean up contacts, check for broken parts.

If no problem, plug headlights in one at time. If problem comes back with only on or the other light plugged in, problem is with that bulb or wiring to it. If problem comes back with either or both plugged in, you are back to chasing the switch or wiring.

Any snow/ice packed in behind the dash or around the headlights? Good luck, surprised it didn't just blow a fuse.

I took your advice and unplugged each headlight bulb one at a time and no change. I took apart the dash and removed the switch. The back of the switch was really dirty so I cleaned it with electrical cleaner and blew it off with the compressor. I re-installed the switch and sometimes it would kill the engine when turning the lights on other times it would not, so it looks like a new switch is in my future.

 

[the8080]

That sounds a lot like there is a bad connection somewhere. The additional current draw from the headlights may be causing the voltage to drop too low to keep the fuel solenoid on.

A new switch may work but you may have something like suggested above. Your tractor may be of the age that you have a lot of corroded connections. Even with a voltmeter you might have a hard time tracking this down. If switch doesn't fix, I think you will need to open all connections you can find and clean. This includes all connectors, both ends of battery cables, all grounds. If you can't isolate the problem, which is very difficult with these multi-contact connectors, these electrical gremlins can be hard to fix.

 

[Buckeyeman]

I replaced the headlight switch with a new one ($65 ridiculous) and every once in while (intermittent) when I turn the lights on I get a split second sputter but it stays running. It seems that when you turn the lights on it's taking juice away from something else. I hate these electrical gremlins.