M4700 ignition switch problems

   / M4700 ignition switch problems #1  

newbury

Super Star Member
Joined
Jan 8, 2009
Messages
14,103
Location
From Vt, in Va, retiring to MS
Tractor
Kubota's - B7610, M4700
I've an M4700 and just lately it seems to have an ignition switch problem.
Put in and turn the key, click, no engine turn over. It's like a safety switch isn't functioning, or I didn't push in the stop switch. A few days ago I'd wiggle the key, try again and it would usually catch by the third try. Today with equipment loaded in the FEL it took about a dozen tries until it finally fired.
Reading threads here there are some suggestions that lubrication with WD 40 or some Silicon might help.
Any advice on how to tell if it's a lube issue or if it needs the $70 replacement?
I'll try lubing next, but I'm a ways away from it so I wanted to post this while I had a chance.
 
   / M4700 ignition switch problems #2  
Lube won't hurt it, but if the battery cables are good, it sounds like water got in the ignition switch & corroded things.
Pretty common.
Screenshot 2024-05-29 at 10.55.43 AM.png
 
   / M4700 ignition switch problems #3  
I've an M4700 and just lately it seems to have an ignition switch problem.
Put in and turn the key, click, no engine turn over. It's like a safety switch isn't functioning, or I didn't push in the stop switch. A few days ago I'd wiggle the key, try again and it would usually catch by the third try. Today with equipment loaded in the FEL it took about a dozen tries until it finally fired.
Reading threads here there are some suggestions that lubrication with WD 40 or some Silicon might help.
Any advice on how to tell if it's a lube issue or if it needs the $70 replacement?
I'll try lubing next, but I'm a ways away from it so I wanted to post this while I had a chance.

Personally I would get the multimeter out and start testing circuits and inspecting connections before throwing parts at it.

Just my 2 cents.
 
   / M4700 ignition switch problems #4  
If moisture got in lube isn't the cure. You could try contact cleaner but cleaning battery terminals and connectors is the proper starting point. After cleaning tighten securely. If you can move the connector it's not tight. Follow the ground leas to the frame. Clean and tighten there, too.
 
   / M4700 ignition switch problems #5  
Personally I would get the multimeter out and start testing circuits and inspecting connections before throwing parts at it.

Just my 2 cents.
Well....here's my thinking.... the OP has a 30 year old open-station tractor with a slanted back style dash looking up at the sky. In that dash is a key type ignition switch that is made to be completely open to the elements. It doesn't even have an excuse for a cover.

All it takes is rain, and then it's just a matter of time until that combo corrodes & begins to fail. The switch is already acting up, so it is already a problem right now - although there could be are other problems as well.

No multimeter needed to diagnose that switch. Although they have a place, a multimeter isn't going to be much help on an intermittant electrical problem.

The switches themselves are slightly rebuildable. Most have tabs that can be bent over. Then it is a matter of whether it is just cleaning contacts or the more difficult one of replacing springs.
rScotty
 
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   / M4700 ignition switch problems #6  
I'd buy a can of CRC contact cleaner and try that first. I had issues with the turn signal lever / switch on my pickup truck and the CRC fixed it.

If it stays outside, you need to cut a small rectangular piece of rubber (old inner tube will work and pop rivet it above the switch so it covers the switch when not in use. What I do with my hunting blind locks.
 
   / M4700 ignition switch problems #7  
Well....here's my thinking.... the OP has a 30 year old open-station tractor with a slanted back style dash looking up at the sky. In that dash is a key type ignition switch that is made to be completely open to the elements. It doesn't even have an excuse for a cover.

All it takes is rain, and then it's just a matter of time until that combo corrodes & begins to fail. The switch is already acting up, so it is already a problem right now - although there could be are other problems as well.

No multimeter needed to diagnose that switch. Although they have a place, a multimeter isn't going to be much help on an intermittant electrical problem.

The switches themselves are slightly rebuildable. Most have tabs that can be bent over. Then it is a matter of whether it is just cleaning contacts or the more difficult one of replacing springs.
rScotty

I hear what you are saying rScotty, it makes sense and there is a good chance you are correct. I just tend to try and poke around a bit and see if there are some obvious signs to the issue at hand when trying to diagnose my equipment. I suppose it depends on how intermittent the problem is as far as using the multimeter goes but also find inspecting connections and wiring can be helpful.

I always appreciate your input rScotty. Please keep the suggestoins coming!!
 

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