Starting problem Ford 641

[MoBill]

I have a 1958 Ford 641 Workmaster that's in really good shape. It has very low hours and was only ever used for mowing. Ever since I got it a few years ago, it's had starting issues. When I push the starter button, which is just a ground for the solenoid, it has always been hit or miss. Sometimes the starter will engage, but usually not. I've been jumping the solenoid with a couple screwdrivers most of the time to start it. Not a problem, but not ideal.

Recently, I decided to get it working right. I assumed the solenoid must be the culprit, so I installed a new 6 volt solenoid (the original solenoid was stamped 6V). The problem remains. Today I discovered that if I push the starter button and tap the solenoid with a screwdriver, the contacts close and the starter spins. It works fine with a gentle tap on the solenoid. what do I do? Try another solenoid again? By the way, the battery is good and reads 6.3 volts. When the starter engages, it cranks very well, so I don't think it's a battery issue.

 

[CoyPatton]

As a solenoid is an electric coil or switch, however you want to phrase it, you could have a faulty solenoid or a lose/corroded mount or a loose electrical connection. The tapping could cause any of the above to momentarily self correct itself and starter engage.

 

[MoBill]

Upon further investigation, I found the back of the ignition switch is warm. This leads me to believe there's a bad connection on the wire going to the "hot" side of the solenoid. Wiggling wires around on the back of the ignition switch solved the problem- temporarily. Tomorrows project is investigating what must be a bad connection on the ignition switch. We're also going to give it a complete tune up. Talking to the previous owner, I found out he never tuned it up in the 20 years he owned it. For all I know, it might not have been tuned up since 1958.

 

[John0829]

I have found most of the time the switch itself is the problem, the internal connections get so worn they no longer will ground good enough to energize the solenoid. Easy to prove, ground the wire that connects to the switch and see if it works like it should. The switches are easy to change out.

 

[jaxs]

Don't you just love the dependability of older tractors. I have the 841 with 4sp tranny & 3sp Sherman my brother bought new. It handled all the work on 300 acreas row crop farm until he leased more land and bought a JD 4020 which might be the finest tractor ever built. The last 4020s were built in early 70s and many are still rolling smoke all over OK and Tx today.

 

[MoBill]

Problem solved. Someone at some point wrapped a bunch of tape around the rubber boot and wires on the back of the switch forcing the contacts together. It looks like the contacts on the switch were barely touching and probably arcing slightly which was causing them to heat up. I took the switch out and got rid of the mess of tape and cannot make the switch fail. I pushed and pulled the contacts and wires around every which way and cannot get anything but "0" on my ohmmeter, so I put the switch back in and it's working just like it's supposed to. I love it when a fix doesn't cost anything but it kinda bothers me that I don't know exactly what the problem was.

 

[jaxs]

I have a 1958 Ford 641 Workmaster. Ever since I got it a few years ago, it's had starting issues. When I push the starter button, which is just a ground for the solenoid, it has always been hit or miss. Sometimes the starter will engage, but usually not. I've been jumping the solenoid with a couple screwdrivers most of the time to start it.

Recently, I decided to get it working right. I assumed the solenoid must be the culprit, so I installed a new 6 volt solenoid (the original solenoid was stamped 6V). The problem remains.

Evidently you understand the concept of how solenoid functions. That lead's me to ask if you every used a piece of wire to jump from solenoid ground post to engine block (ground) before buying the new solenoid ?

 

[MoBill]

No, I admit I didn't. I should have as I do understand how the solenoid works. I might have wasted $20 on the new solenoid. Since my last post, I found that a couple times I had the same starting problem. Reaching around behind the sheet metal and wiggling the wires on the back of the ignition switch worked. The switch has an intermittent contact problem internally. A new $18 switch from Tractor Supply and we're back in business.