B7800 Pedal Problems?

Temp97 · Jul 26, 2010

When I start my tractor and hit the pedal to move (forward or reverse) the tractor shuts off????? I'm thinking something is shorting out but not sure where. 1st thing I checked were the connections under the seat and they seem OK. Any one else have this problem or suggestions. (I hate tracing electrical problems).

Thanks

MikeInEburg · Jul 26, 2010

Almost certainly a safety switch issue - simply a matter of finding it. I agree that the seat would be my first suspect... Good luck!
Mike

riptides · Jul 26, 2010

Engage the PTO while your sitting and then stand up. What happens?

art · Jul 26, 2010

Operator switch under the seat is the problem more then likely!

rswyan · Jul 26, 2010

art said:
Operator switch under the seat is the problem more then likely!

Uhhh ..... does the B7800 even have such a switch ?

Know my B2910 doesn't .....

MikeInEburg · Jul 26, 2010

rswyan said:
Uhhh ..... does the B7800 even have such a switch ?

Know my B2910 doesn't .....

My B7800 does....

rswyan · Jul 27, 2010

MikeInEburg said:
My B7800 does....

What year is it ?

Temp97 · Jul 27, 2010

riptides said:
Engage the PTO while your sitting and then stand up. What happens?

I got around to trying that last night, here's what happens. Sitting down and engaging the PTO it shuts off instantly. Get off the seat and engage the PTO it shuts off after about 3-4 seconds. I checked all the wires and cleaned them (under the seat) but no luck. The tractor is a 2007. There is a small box (circuit breaker looking thing) under the seat that I'm starting to believe may be shot. This weekend If I have time I'm going to crawl underneath it and trace wires/connections before I have to take it to the shop,,,

riptides · Jul 27, 2010

Temp97 said:
I got around to trying that last night, here's what happens. Sitting down and engaging the PTO it shuts off instantly. Get off the seat and engage the PTO it shuts off after about 3-4 seconds. I checked all the wires and cleaned them (under the seat) but no luck. The tractor is a 2007. There is a small box (circuit breaker looking thing) under the seat that I'm starting to believe may be shot. This weekend If I have time I'm going to crawl underneath it and trace wires/connections before I have to take it to the shop,,,

Ok, sounds interesting. There is plug right by the seat, have you unplugged that, cleaned it, and gotten it back together? Mine was acting up like this one day. I think I also adjusted the seat itself a few times. Trying to distribute the weight while trying to figure it out myself.

I am thinking if it is electrical, you would not be starting at all, or the behaviour on the shut-off would be identical.

jonsstihl · Jul 27, 2010

if you tilt the seat up while you engage the pto if your seat switch is bad it should still keep running because there is a second switch on the seat that activates when the seat is tilted up so that you can run the pto without being on the seat.

this test will tell you if your seat switch is bad. if the pto runs with the seat up but dies with the seat down it means that the tractor thinks no one is in the seat

hope that helps

DiezNutz · Jul 27, 2010

Classic seat bottom safety switch.

Pull the two wires off of the switch terminals, jumper them together - *but wrap them (e.g., with electrical tape) so they don't short to any other part of the tractor and blow a fuse* - and see if that doesn't solve your problem.

If it does, you need a new switch. Or, you can jumper the wires together permanently if you don't care for this "feature".

Temp97 · Jul 28, 2010

Dieznutz, Didn't get a chance to look at it last night but I will run that test tonight, thanks. Also Jonsstihl, it does run with the seat up and I was wondering why there were 2 switches.

DiezNutz · Jul 28, 2010

In case I wasn't clear enough, it's the seat bottom switch wires you want to jumper/test. Not the seat tilt switch (the one at the front edge of the seat) - it isn't your problem, you can leave it be.

The sole purpose of the tilt switch is to allow you to run the (rear only) PTO stationary while not sitting on the tractor. Normally if you had the PTO on and got up, the tractor would quit. Tilting the seat is an "override" that tells the tractor "I'm definitely not sitting on the tractor but I definitely want to run the PTO."

Everything you described is what happens when the tractor thinks you're not sitting on the seat *and* the seat isn't tilted - i.e., bad seat switch isn't closing the circuit.

orezok · Jul 28, 2010

Here's the Operator Presence Control manual pages for the 7800

Temp97 · Jul 29, 2010

DiezNutz said:
In case I wasn't clear enough, it's the seat bottom switch wires you want to jumper/test. Not the seat tilt switch (the one at the front edge of the seat) - it isn't your problem, you can leave it be.

The sole purpose of the tilt switch is to allow you to run the (rear only) PTO stationary while not sitting on the tractor. Normally if you had the PTO on and got up, the tractor would quit. Tilting the seat is an "override" that tells the tractor "I'm definitely not sitting on the tractor but I definitely want to run the PTO."

Everything you described is what happens when the tractor thinks you're not sitting on the seat *and* the seat isn't tilted - i.e., bad seat switch isn't closing the circuit.

Ooops, to late. I ran the test last night and read your new message this morning. I did what you said and taped the 2 wires together for the seat tilt switch (left one in pic) and it worked,, seat up, seat down w/PTO on... Now that I'm thinking of it I didn't actually sit on the seat to make sure there was pressure on the seat switch (round one),,,,