B6200 No Start

[freewheel3]

B6200 HST 4wd. Battery is good at 12.8v, same at post on starter. But I only get 10.8v on the wire on the solenoid when the key is turned to the crank position, and it takes about 15 seconds to get up to that 10.8 from about 9.2v.
I've checked all connections and grounds that I can get to without removing the dash.
I can start the unit by jumping the solenoid, but not with the key.
Why?

 

[Mark_BX25D]

You either have a bad battery (most likely) or you have a bad connection somewhere. Corroded cable or connector.

Just reading a voltage doesn't mean the battery is good.

 

[freewheel3]

You either have a bad battery (most likely) or you have a bad connection somewhere. Corroded cable or connector.

Just reading a voltage doesn't mean the battery is good.

I know that. The battery starts the tractor just fine if you jump the solenoid. I don't know why the wire coming from the ignition switch that energizes the solenoid only has 10.8v though?

 

[Mark_BX25D]

Corrosion somewhere. Try this - get a test light and try it on that same terminal. If it lights, measure the voltage. I'm betting it will be lower with the test light in place than without the test light.

 

[Dave_eng]

Remove the Black-white solenoid wire from the key switch terminal #50. Apply 12 volts to that wire directly from the battery +.

The engine should crank immediately. If it does not then the safety switch may have too much resistance and lowering the available voltage.

If the engine does crank, then the key switch or the circuit supplying the key switch is suspect.

Corrosion in a fuse case is possible. There is one wire connector in the harness that feeds the key switch. Check for any signs of corrosion or overheating.

Your tractor's wiring is simple so finding the problem should be possible.

Dave

 

[freewheel3]

Remove the Black-white solenoid wire from the key switch terminal #50. Apply 12 volts to that wire directly from the battery +.

The engine should crank immediately. If it does not then the safety switch may have too much resistance and lowering the available voltage.

If the engine does crank, then the key switch or the circuit supplying the key switch is suspect.

Corrosion in a fuse case is possible. There is one wire connector in the harness that feeds the key switch. Check for any signs of corrosion or overheating.

Your tractor's wiring is simple so finding the problem should be possible.

Dave

I'm assuming the safety switch you're referring to is the one on the clutch. The problem seems to be before that switch because I have the same 10.8v going into it and out of it. I'll pull the ignition switch tomorrow and run the wire you suggested.
Thanks for the input.

 

[N3BP]

Your Ignition switch may be bad. I had to replace the original one on my B7200 last year. The contacts inside the switch were shot.

 

[Dave_eng]

I'm assuming the safety switch you're referring to is the one on the clutch. The problem seems to be before that switch because I have the same 10.8v going into it and out of it. I'll pull the ignition switch tomorrow and run the wire you suggested.
Thanks for the input.

The wiring diagram only shows one safety switch on your tractor.

You can only do a voltage drop test on any switch with a load (amps) flowing through it. This would mean the starter solenoid would have to be engaged otherwise your test is meaningless.

Do the test removing the #50 wire.It will tell you a lot.

Dave

 

[freewheel3]

The wiring diagram only shows one safety switch on your tractor.

You can only do a voltage drop test on any switch with a load (amps) flowing through it. This would mean the starter solenoid would have to be engaged otherwise your test is meaningless.

Do the test removing the #50 wire.It will tell you a lot.

Dave

The voltage was checked on both sides of the safety switch with the key in the crank position. The voltage slowly climbed evenly on both sides of the switch from 9.2 to 10.8v, with the clutch pedal depressed. This is the same reading I get at the solenoid wire with the key in the crank position.
I haven't been back to the tractor since I posted, but yes, I will do the #50 wire test when I get back to it. I will report my findings. It does appear to me that the symptoms indicate the problem is at the ignition switch, either loose connections or corrosion of connections / contacts.

 

[freewheel3]

Finally got time to finish the repair. It was the ignition switch that must have been corroded or something inside. It's a sealed unit so I didn't bother to open it up. New switch and it's a 100%.
Thanks for everybody's input.

 

[Dave_eng]

Finally got time to finish the repair. It was the ignition switch that must have been corroded or something inside. It's a sealed unit so I didn't bother to open it up. New switch and it's a 100%.
Thanks for everybody's input.

Thanks for posting the outcome.

It is a help to everyone's learning

dave