Starting problems with Montana 535 Limited

[tparslow]

We operate food pantry and community gardens with our main tractor, Montana 535 Limited. It is perfect for our operation. However, it has a starting problem. Most of the time we start it by "jumping" across to the solenoid. Not a safe procedure. But it starts. Once it warms up no problems. Let it set, cool down and its a 50:50 whether it will start.

Several people have looked at it. Replaced ignition switch, replaced solenoid, starter is okay, battery is okay, checked all wiring with no success. It appears to be the safety switch on the high-low shift. Not sure. We by-passed that switch and still have problems. A wiring diagram would be helpful. Is there a relay switch that could be a problem?

Please weigh-in with your thoughts. Thanks for any help.

 

[Guesseral]

Have you tried to see if Montana has a wiring diagram for the tractor? If you go to there site and fill out the form they have under contact us they should get back to you, or at least they have for me. It can't hurt. If you do get the wiring diagram (or not) you need to trace out the wire that pulls in the coil on the solenoid, if it goes through some type of safety switch that is bad there you go, heck it could be a broken wire that only make contact when it wants to.

 

[mwb]

I would 'start' by putting a multimeter across the solenoid (small posts) and see if it is getting power when the key is turned (sounds like it isn't). If it isn't getting power then work backwards - disable all safety switches one by one until you find the culprit. PTO might have an interlock on it, seat switch, clutch.

If you have to jump the solenoid you don't have to go across the big posts, just put a small jumper between the positive on the solenoid (from the battery) to the small solenoid post (from ignition switch). You won't get big sparks and weld marks on your screwdriver this way.

Just remember that you could start your machine while in gear! :shocked:

 

[mwb]

I just looked at the schematic for my tractor (not that is has to be the same wiring as yours) and mine has a specific "interlock relay" that is fed my the various interlock switches. This relay is the common denominator (on mine) - check your fuse panel for a relay that might be bad. A faulty relay might also explain why it works when the machine is hot.

You might also try posting in the parts/repairs forum; you will get more views there.

Here is a link to a parts manual for you http://www.farmtrac-tractor-parts.com/files/FTS435-535.pdf

Is that machine a copy of an older Ford / NH? Color aside, the shape and sheet metal look it.