790 won't start

[metalcaster]

I ran my 790 about 4 hours yesterday and drove to the local fuel station to refuel. Shut the tractor off to fuel and after I paid for the fill up was surprised that the beast wouldn't even turn over. Just a dim light on the dash when the key was turned.
Fortunately an old school mate showed up to fuel his small deere and was able to push me to my shop. Tried to push start a couple of times and his tractor was just too small to get the engine to turn even spin. Put a trickle charger on the battery overnight.
This afternoon all I got was clicking when I turned the key. Cleaned the battery terminals and the ground connection. Still just the clicking along with a slight movement of the crank. So I'm assuming that the battery is shot. I'll head to my friendly NAPA store for a new one tomorrow. Any one got any other ideas?

 

[manganos]

You said "shop" so I assume you have some basic tools. First thing I would do is disconnect the battery and check it with a V Ohm meter to measure the voltage. I would agree that your battery is in need of replacement. Let us know what it turns out to be

 

[amaxwell]

New Battery sounds right.

 

[Willl]

Do you have a volt meter ?, real easy to check that battery yourself.

And if the batts good, wouldn't be much harder to trace down your fault.

 

[Trails2004]

Depending on the age of your tractory you may want to check your alternator.

 

[RoyJackson]

Make sure your PTO lever is in the off position.
Before you buy another battery, jump yours off a known good battery (after cleaning the terminals and ground strap). If it starts, great! If it doesn't crank fast, might be your starter. Tap it with a hammer or mallet (might be the bendix sticking). You can short across the starter's terminals, but be 100% sure the tractor is in neutral...100%!!!!
If it still doesn't crank, I'd suspect a safety switch.

BTW, I had a starting problem with my 790 once. It wouldn't crank initially, but the starter turned fast when being jumped (still wouldn't start though). After doing all I knew how to do (I'm no electrical wizard), it went to the dealer. Turned out to be a ground terminal wire that had corroded at the connector. Only cost a fw bucks to fix (not including the transporting costs to the dealer).

 

[metalcaster]

"Make sure your PTO lever is in the off position.
Before you buy another battery, jump yours off a known good battery (after cleaning the terminals and ground strap). If it starts, great! If it doesn't crank fast, might be your starter. Tap it with a hammer or mallet (might be the bendix sticking). You can short across the starter's terminals, but be 100% sure the tractor is in neutral...100%!!!!
If it still doesn't crank, I'd suspect a safety switch."

PTO is in off position.

I used a charger with a boost setting with out any success. Also jumped it from a battery on a fork lift that is good with same result. removed the ground cable, cleaned the frame and the lug and re-connected, still no success. Just a slight rotation of the fan and some clicking at the starter. Tapped the starter without any change.

 

[farmerjim]

mine did just about the same thing about 1yr ago was chipping some brush and shut it down to clean up and move 2 the next pile, went to re start and nothing not even turn over tried to jump it off my truck same results. i thought it was a safety switch but then b4 tearing into that checked the batt w/ a vom and it was reading just about 12v, tried to trickle charge it over night and restart barely turned over went to napa and they load tested it and it was dead, new batt was around $95.

 

[RoyJackson]

PTO is in off position.

I used a charger with a boost setting with out any success. Also jumped it from a battery on a fork lift that is good with same result. removed the ground cable, cleaned the frame and the lug and re-connected, still no success. Just a slight rotation of the fan and some clicking at the starter. Tapped the starter without any change.

I'm thinking a safety switch now. IIRC, you have three: one under the seat, one for the PTO lever and one as a neutral safety switch. Since I've never had to mess with them (except the seat switch for off seat operation) and I gave the tech CD away when I traded off the 790, I can't help you on the locations of these switches (except the seat switch...you may as well flip the seat forward and check those connections).
SO! I'm going to suggest you repost this in the Deere Owning/Operating forum. There's a number of 790 owners and some have the tech manual/CD. To help, post the serial number off your tractor too (plate is just above the PTO guard). There were three different owners manuals (due to changes during the production run) and that may apply to the tech manuals as well.

Wish I could be of more help...hope farmerjim's post works for you.

 

[Willl]

Just a slight rotation of the fan and some clicking at the starter.

Says your switches are fine and you've got a voltage problem.

Be it battery and/or connections.

 

[metalcaster]

If it was a safety switch I wouldn't get any action when turning the key. The tractor is a 2005, the battery was OE. I'll take it to NAPA and have them test it in the morning. However it was a father's day shot with no seat time. What a disappointment.

 

[banjodunn]

G'day i agree if it was a safety then you would not get any starter engagement at all, you can do a simple load test yourself if you have a volt meter clip it on to the batt terminals and read the voltage before cranking and whilst trying to crank, you should not drop below about 9 volts. You have got me a bit worried when you say that you get no more assistance with the booster batt on it you may have a crook starter i hope not for your sake.


Jon

 

[clemsonfor]

may be a bad starter, or the alternator or regulator also bad the reason it may have went bad as well.

 

[metalcaster]

Alright, took the battery to my friendly NAPA store and put it on their tester. It checked out as a good battery even after 2 test cycles. I knew I was then in for some troubleshooting.
The NAPA clerk suggested that I take a good battery back and see if it made a difference; so I did. Put the terminals on and the engine spun like it did when it was new. Went back to the store and signed the charge slip promising to scrape off the appropriate date for warranty. All is well once again.

 

[RoyJackson]

Alright, took the battery to my friendly NAPA store and put it on their tester. It checked out as a good battery even after 2 test cycles. I knew I was then in for some troubleshooting.
The NAPA clerk suggested that I take a good battery back and see if it made a difference; so I did. Put the terminals on and the engine spun like it did when it was new. Went back to the store and signed the charge slip promising to scrape off the appropriate date for warranty. All is well once again.

I'm really surprised you old battery would spin the starter when it was jumped. That makes me wonder if the terminals were clean enough (figured you'd already checked that though).
Anyway, glad your 790 starts good now and very glad it wasn't a safety switch.

 

[metalcaster]

My first thought was to clean the terminals. Did that and nothing. At least they were clean when I put the new battery in. Thanks everyone for your help and suggestions.

 

[zuiko]

Check the ground if you haven't already. I have had problems with that on my 990. I have to go tighten up the bolt every once in a while. When it gets loose sometimes it starts and sometimes it doesn't.