790 starting problem

CAL123 · Aug 20, 2009

I'm having trouble getting my 790 starting...it acts as though the tractor is in gear or PTO is engaged, though they are not. I had been mowing and hopped off the tractor for a bit due to lightning/storm- turning off the key. About 30 minutes later when I tried to fire it up again...nothing. I've worked the PTO and gears, but the engine won't turn over (battery is good though). Thanks for any suggestions!

irwin · Aug 20, 2009

CAL123 said:
I'm having trouble getting my 790 starting...it acts as though the tractor is in gear or PTO is engaged, though they are not. I had been mowing and hopped off the tractor for a bit due to lightning/storm- turning off the key. About 30 minutes later when I tried to fire it up again...nothing. I've worked the PTO and gears, but the engine won't turn over (battery is good though). Thanks for any suggestions!

The seat switch is a common issue. Flip the seat up and pull the switch plunger up and retry it.

mfreund · Aug 20, 2009

There has been a rash of posts where the battery tested good but was really bad. Check the battery voltage with the key turned to crank and see what you have for voltage. There seems to be single cells going out and batteries test good,(by voltage) but don't have the amps to turn over the tractor.

Willl · Aug 20, 2009

CAL123 said:
it acts as though the tractor is in gear or PTO is engaged, though they are not.

When you say it "acts", what exactly does it do ?

CAL123 said:
(battery is good though)

Says who ?, what is your battery voltage ?

RobS · Aug 21, 2009

All good suggestions, also check your fuses. I had, only one time, a similar situation and it turned out to be a fuse.

CAL123 · Aug 21, 2009

dash lights up when the key is on...when I turn the key to start, lights go out and nothing happens (doesn't crank)...just like it does when either PTO is engaged or tractor is in gear and you try to start

kennyd · Aug 21, 2009

CAL123 said:
dash lights up when the key is on...when I turn the key to start, lights go out and nothing happens (doesn't crank)...just like it does when either PTO is engaged or tractor is in gear and you try to start

Do you have a voltmeter? You need to check the battery voltage while turning the key.

irwin · Aug 21, 2009

CAL123 said:
dash lights up when the key is on...when I turn the key to start, lights go out and nothing happens (doesn't crank)...just like it does when either PTO is engaged or tractor is in gear and you try to start

I'm with Kennyd here. You need to know what shape the battery is in, and the connections. A bad ground (or loose/bad connection) will act just like that.
Try jumping the battery with a known good battery. Try removing/cleaning all main connections..Try jumping the starter solenoid with a screwdriver...better make sure it's in neutral! Try something that will give you answers.

Is the battery truly good?

Are the connections truly good, clean and tight?

Is the starter any good? don't want to try the screwdriver with the starter on the engine..remove it and give it power and ground.

Do you have a safety switch gone bad?

Is the ignition switch bad?

sean miller · Aug 21, 2009

you definitly need to know battery state of charge and if the battery has removable caps use a hydrometer fully charged specific gravity should read 1275.verify that the seat safety button is working properly use a jumper wire as a quick test can also perform a voltage drop test on the positive and negative cables and starter motor.