JD 950 Starting Problems

[Bladerunner6]

I have a new problem with my JD 950. It has a problem starting. It doesn't do anything on turning the key. It was working fine then suddenly wouldn't turn over. The engine red light comes on and I hear a faint single click when the range and gear shifters are in the neutral position.

However, if I fiddle around with the shifters I can sometimes seem to find a sweet spot where it cranks normally. Those occasions that I can get it to crank, I can turn it off and it will restart with no problem. However, leave it a couple of days and I am back to square 1. Logically it would seem the problem is with the neutral switch(s). However, after reading a couple of the threads on TBN on not starting, I am wondering if maybe its not the obvious thing but perhaps a battery or starter issue. The battery is 4 years old and I put a rebuilt starter on 3 years ago.

Any suggestion?

 

[kebo]

It won't hurt anything to take the battery cables off and thoroughly clean all the terminals and posts, and the grounds as well, and the connections to the starter motor/solenoid as well. I suspect that it's just a coincidence that it cranks with the shift levers in a certain position. I could be wrong though, and maybe it's something to do with a safety interlock switch? It just sounds like a connection issue to me, and you might want to get your battery checked with a good battery tester too.

I have one other suggestion to try... next time you turn the ignition, and you hear the faint click, take a dead blow hammer and hit the starter a good rap or two, while holding the key in the crank position. (This is assuming the starter solenoid is integral with the starter motor, like on the 750's). If it suddenly spins over and cranks up, I think you have a low voltage condition on the starter solenoid. I've owned two 750's and on one of them, it was doing similar to what your 950 is doing. I wound up having to add an auxillary relay to get it to crank reliably every time. The additional relay helped overcome the low voltage condition.

This was due to all the voltage drops from undersized wiring, and all the connections in the starter/cranking circuit that can develop corrosion over time. These poor connections will eventually add some resistance into the circuit, which will cause voltage drops and tend to limit the current flowing through that circuit, when you turn the key to crank. Everybody knows that diesel engines have higher compression, which takes more cranking amps, especially in colder weather. Anything that tends to reduce the voltage or current flowing through the electrical circuit for the starter motor is bad.

Hope you get it figured out! Nothing worse than going to crank up the tractor and it won't crank when you need it!

 

[arrow]

Had a problem like this with my JD 750. I would also play with the shift levers and sometimes it would start perfectly and other times not so much. Perhaps just enough frame stress when pushing in the clutch would be enough to create a viable ground. Turned out to be a loose ground. Hope yours is as simple a fix. If your starter is not failing, I would agree with Kebo as it would seem you may also have a loose connection somewhere. What also caused a starting problem once was when I had to replace the voltage regulator on mine. Yours fits the 850, 950 and 1050 tractors. You can find them on ebay for cheap enough.
Also, look at where your battery cables are entering any sheet metal passageways. If not grommeted, you may have rubbed to bear wire causing an intermittent short.

 

[Bladerunner6]

I appreciate the responses from kebo, and arrow. I will do some maintenance on the battery connections, thats overdue. However, i tried kebo's suggestion with the mallet and it fired right up and has continued to do so without fail.

 

[Egon]

It's surprising what a good mallet can do. That used to be a very common treatment on the starters of years ago.

 

[kebo]

I appreciate the responses from kebo, and arrow. I will do some maintenance on the battery connections, thats overdue. However, i tried kebo's suggestion with the mallet and it fired right up and has continued to do so without fail.

That is exactly what one of the JD 750's I used to have was doing. It sounds like it has a low voltage condition to the start solenoid when you switch the key to the crank position. I think you have a loose or corroded connection somewhere in the wiring for what I call the "cranking circuit". The cranking circuit consists of all of the wiring and components used to crank the motor. Hope you can find out where the problem is on yours!

 

[Dave M7040]

That is exactly what one of the JD 750's I used to have was doing. It sounds like it has a low voltage condition to the start solenoid when you switch the key to the crank position. I think you have a loose or corroded connection somewhere in the wiring for what I call the "cranking circuit". The cranking circuit consists of all of the wiring and components used to crank the motor. Hope you can find out where the problem is on yours!

The low voltage to the starter solenoid is an even bigger problem on garden tractors when they are stored outdoors. the many safety switchs on them all start to crud up a bit. Since each safety switch is in series with the next one, the end result even if each switch drops the voltage just a little, by the time it get to the starter solenoid the voltage is too low to pull in the solenoid.

The fix is a simple relay and all the wires you need are already at the starter or a short pieces of wire you connect to the heavy battery terminal on the starter to supply a good signal to the solenoid.

This picture of a solenoid on a cub cadet shows how easy the wiring is. A relay and wiring socket for the relay is about $10. The wiring socket so you can do a neater job than this one with push on terminals.

Here is a link to a relay and wiring socket on amazon for less than $5
Amazon.com: Car Auto Truck Relay & Socket SPDT 12V 12 Volt DC 4A AMP 5Pin: Car Electronics

This illustration shows how to wire the relay to the starter solenoid.

Dave M7040

 

[arrow]

It's surprising what a good mallet can do. That used to be a very common treatment on the starters of years ago.

Hey, if they have them in the operating room at hospitals, they must be the handy tool. I bet they use them more times than they tell you. "doctor, the patient's heart has stopped".... "Hammer" he replies.
I respected the vast amount of uses for hammers as the proper tool from being a youngin. How many times did pops say, "keep that up and I'll take a hammer to ya."

 

[CADplans]

When I first visited my brother-in-laws farm,, one of the FIRST things he taught me;

"NEVER use a BIG adjustable wrench for a hammer,,,,,,,

when a small adjustable wrench will do,,,"

 

[Shaneard]

When I first visited my brother-in-laws farm,, one of the FIRST things he taught me;

"NEVER use a BIG adjustable wrench for a hammer,,,,,,,

when a small adjustable wrench will do,,,"

I always heard "if you can't fix it with a hammer then you have an electrical problem".