john deere 855 pto blows fuse when I sit on seat

[Groundfx]

So I was blowing snow and everything was fine. then for no reason it stopped when I looked the 10 amp fuse was blown. replaced it and tested with me standing outside the tractor and will work fine but when I sit on seat it blows fuse. can anyone help please?

 

[bigtiller]

I can't help you, but you reminded me of years ago, having a horse that acted the same way. She would stand there and look pretty but wouldn't let anyone ride her.

Come to think of it, I had a girl friend like that too. :laughing:

 

[CobyRupert]

Just a guess, but sitting on the seat and closing the switch allows current to pass through the switch and it's probably shorting to ground (frame) either at the switch or somewhere downstream (in the circuit) of the switch, before the circuit reaches its normal "load" (i.e. the starter solenoid or relay). Without this normal load resistance, the large short circuit current blows the fuse. But then the questions is: how did it start in the first place?

First, I think you need to know what the seat switch is suppose to do (i.e. what does the circuit do):
1) What is suppose to normally happen when tractor is running and you stand up?
2) Normally, will tractor start if you're not on the seat?

Another, slim possibility is, is your key switch broke, so that when sitting on the seat your actually trying to start a running motor? Probably not as you'd probably hear this and burn the starter out before you blow the 10amp solenoid fuse.

 

[k0ua]

I can't help you, but you reminded me of years ago, having a horse that acted the same way. She would stand there and look pretty but wouldn't let anyone ride her.

Come to think of it, I had a girl friend like that too. :laughing:

I had a girfriend just like that too!

 

[Industrial Toys]

If it is anything like the 770 and I suspect it is, there is a series of switches that are in that circuit for the PTOs. I'm guessing just a pinched wire, maybe even at the seat. I doubt a shorted to ground seat switch.

 

[zzvyb6]

With you off the seat and standing next to it, the tractor shouldn't start or stay running if things were normal.

 

[Groundfx]

funny you mention the key as last year the tractor died in the middle of the road and I made a jumpset wire from the starter. so first I turn the key to the on position then touch the wires together to get the starter to engage. do you think cause that part of the ignition is messed that could be the case?

 

[Groundfx]

yes this is true so is this a switch fault or ignition switch fault. it has let me get off the tractor since 98 and it was new in 96 so I used to it not stopping

 

[Industrial Toys]

I once had a problem with my 770. It just quit, or did not start. Don't remember, but I traced it to the timing module for all that safety circuit stuff. I didn't even know it was there, just to one side of the instrument console and a little below. There was one fuse in there, I recall and it was blown. Replaced it and everything was fine, although I never did find out why it blew and never had a problem again???

 

[CobyRupert]

yes this is true so is this a switch fault or ignition switch fault. it has let me get off the tractor since 98 and it was new in 96 so I used to it not stopping

Do you mean:
1)That from 96-98 it wouldn't start unless you were sitting down AND would stop running if you stood up?
2) Then one day, by itself, it would let you start it without sitting AND stays running if you stand up?