Need help on Ford 641

[Bob Kellogg]

Need help on my Ford 641 tractor
I converted my Ford 641, gas, 134 cu in) to 12 VDC about a year ago and that was the best thing I have ever done to it. I did not change the solenoid switch or the starter - they are still 6 VDC - because most on line instructions indicated that was OK. It starts in anout 0.25 seconds so I figured those units will be overpowered for such a short time that it won't matter. OK - a few days ago I was mowing, shut the tractor down to replace the clothes line, tried to restart and it was like someone had removed the battery - no sound at all. Tested the batt. It was OK. Tried my truck battery anyway (just in case) . No sound either. I replaced the solenoid w/ another 6 VDC unit (used) and got a very slow crank but not enough to start it. I hot wired the starter motor and got the same very slow crank but no start. The starter turned so slow it was worse than I experienced with it when I had a 6 VDC battery. I have a 12 VDC solenoid on order but haven't received it yet. Doubt that will help since hot wiring didn't work. Is my starter bad? Ideas?

Bob

 

[mgriff543]

Running the 6v solenoids and the starter for such a short time on 12v will not damage them. As far as your problem goes I think it may be a bad ground, either the main cable or the starter housing to the block. If these are shiny clean and tight then it's certainly possible you have come to the end of your starter brushes.

Good Luck, Mike

 

[Bob Kellogg]

I solved the problem this AM and I think you may be right, Mike. I did replace the solenoid with a 12 VDC one (delivered yesterday) AND cleaned the + and - cable ends. Can't say for sure which solved the problem but it started right up making me a happy camper. I certainly can't explaon why hot wiring the starter did not work but I can easily forget about it now the tractor runs. Thanks.
Bob

 

[Keith Williams]

I think you have all the facts you need. You took the selonoid out of the equation when you "hot wired" it. Bad/loose connections were your problem. I bet you could put the original sel back in at it would work fine!
Keith

 

[Bill Radford]

Make sure you dont have a car solenoid.. looks
similar. When I did my 641 I finally used a 6v
solenoid. Works fine. If you get a 12 volt solenoid,
get the one for the diesel
I just about tore my hair out over this a while back
because I mistakenly tried to use a ford truck
solenoid. Wont work.

 

[Bob Kellogg]

Bill, I think that is because of the grounding. The Ford solenoid isolates the ground from the case and others are grounded to the case. When I converted from 6 to 12 V I tried to use one of the many ground versions I have only to get very frustrated. I found out they were grounded so I re-installed the old 6 V one and problem solved. Just yesterday I installed the non-grounded 12 V version.

 

[Bill Radford]

Its getting hard to communicate what you need to parts people these days.. go in one of the chain stores and the first thing they want to know is what year and kind of car you need the part for. They use a computer and very few know how to use a cross reference book (or a book, period)
Most think a 12 v solenoid is a 12 v solenoid and dont realize the difference between a grounded and non grounded bracket. 6 volt was the simplest way to go for me.