1980 john deere 850 compact great..........when running!!!!

[gibbit70]

hello everyone new here and making my first post.. I have owned this tractor for a smidge over a month and have spent two and half weeks tracking down issues and waiting for parts. hopefully someone here can help me put an end to the madness? so lets start at the beginning; got it home started fine and drove it round a bit all is good for a day or two then no start, jumped fine so thought alternator. replaced that jumped her and off to work seemed like it was charging, then dead again. did some reading on here and got voltage regulator so got that checked all the wiring and all was good once again fixed shut her off and on a few times and dead. doubled checked everything with volt meter all good except battery out to get a battery and once again all is well, I thought been about five days sense the battery purchase and she is sitting dead out on my property, I did change battery cables with the battery. i'm at a loss no ideas I don't get it? any helk would be great before I just burn her where she sits.:confused2:

 

[jd110]

Are you sure the battery is dead? The 50 series are great tractors but one thing they are prone to since they have aged is starting problems due to voltage loss to starter. They never were equipped with starter relays from the factory and with age and corrosion going from key switch to neutral switches and then to the starter results in not enough voltage getting to the starter solenoid to energize it. Adding a starter relay in the circuit assures that 12 volts gets to the small starter solenoid terminal for reliable starting. Deere makes a couple of kits to add this, but not specifically for this model. I like the one designed for early rowcrop tractors. It has a heavy duty relay that will probably last the life of the tractor, but it is a bit pricey. Part number RE44536. Some people on the forums have used a cheaper alternative from lawn and garden tractors and it works but has a smaller cheaper relay. Part numer AM107421. you can also wre in a elay without the kit if you prefer.

 

[prs]

With my 650, the ground strap gave me the symptoms described a time or two. The rectifier/regulator has been trouble some several times, having been replaced 4 times since 1983.

prs

 

[CADplans]

First, I always remove the ground cable and clean the connection to the tractor.
(hopefully the battery end is clean)
I have had at least four tractors that the cable/frame connection was the cause of intermittent starting.

If the battery goes dead over a few days, there must be a current draw.
With EVERYTHING turned off,,, remove one of the battery terminals.
Connect a 12 volt light bulb between the cable and the battery post.
The bulb must not glow at all.

If the bulb lights at all, there is a load on the battery which can cause it to discharge.
You have to then look for that issue.
Sometimes removing fuses one at a time will help identify the issue.

Luckily, my JD 650 has not had any of these issues,,,, YET!! :confused2:

My 650 is getting old :laughing: I ran it for over 6 hours today!! :thumbsup:

 

[JOHND755]

First, I always remove the ground cable and clean the connection to the tractor.
(hopefully the battery end is clean)
I have had at least four tractors that the cable/frame connection was the cause of intermittent starting.

If the battery goes dead over a few days, there must be a current draw.
With EVERYTHING turned off,,, remove one of the battery terminals.
Connect a 12 volt light bulb between the cable and the battery post.
The bulb must not glow at all.

If the bulb lights at all, there is a load on the battery which can cause it to discharge.
You have to then look for that issue.
Sometimes removing fuses one at a time will help identify the issue.

Luckily, my JD 650 has not had any of these issues,,,, YET!! :confused2:

My 650 is getting old :laughing: I ran it for over 6 hours today!! :thumbsup:

I have a 750 and a 755 and they run for hours no problem. Bought the 750 a year ago and bought the 755 this spring. 755 has really low hours but sat outside and all the linkages were rusted up to the point none of them would move. Could not engage the PTO, could not select front, middle or rear PTO, could not change from high, neutral or low range, could not engage 4 wheel drive and could not lock rear differential.Got everything moving and mounted the mid mower deck on it and it cuts great.

 

[elkaybmx]

Check to ensure connection for the safety switch for the transmission is good and clean. Also the one at the PTO lever. I've had corrosion on these cause issues. They are open molex connectors versus weatherpacks.