3 post solenoid

[moday]

The solenoid on the 640 that Im working on was cracked. I bought a new one but it seems like the starter is always engaged when I hook up the battery. Did I maybe install backwards and damage the new solenoid or maybe its bad and always on? I think the little post goes nearer the battery cable and would it damage the solenoid if I had that backwards? What is the correct orientation for the 3 post solenoid? The photo attached is how I have it now and it still cranks the starter when I hook up the battery. Thanks in advance! Moday

 

[old]

Yes it could be hooked up backwards and if so it does funny things.

 

[Sean in PA]

It is also possible that it is not the correct solenoid for that application Just because it has 3 posts does not mean that it's wired internally the same as the original solenoid.

 

[Keith-OR]

I can't really tell how you have the starter solenoid hooked up!! if you have a 12 volt wire going to the small post on solenoid, it is hooked up WRONG. The only wire that should be hooked to that small terminal, is the wire from the starter switch by the gear shift. it is easy to see if you have the correct solenoid, is run a jumper wire from small terminal to ground. which should engage the starter..
On Ford tractors that wire is taken to ground by push button starter switch by the shifter, that is a safety, to keep you from starting tractor while in gear!!!

 

[Tim PloughNman Daley]

99.98% OF ALL NON-STARTING ISSUES ARE DUE TO INCORRECT WIRING REGARDLESS IF 6V OR 12V. Do you have your ESSENTIAL MANUALS? Wiring diagrams are all in there. Also as mentioned, be certain you have the correct parts. The Starter Motor is p/n FAC-11001-E, and the SOLENOID is p/n 21A-11450.


FORD TRACTOR 53-59 WIRING DIAGRAM:

STARTER MOTOR RELAY (SOLENOID) INFO:

FORD 600/800 ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:

Tim Daley(MI)

 

[used red MN]

Tim has given you a lot of information but I fear some of this may be coming in over your head just judging by the questions you have asked. For one a really cheaply built solenoid can simply weld or electrical arc itself into the ..always on.. position but we will come back to that. Did the tractor operate properly with the old solenoid in place? It looks to me like you may be going together with a project and this is all new wiring that has been installed. The red wire on the small terminal under the rubber boot where is it connected to? If you disconnect that and hook up the battery what happens? If it still wants to turn the starter something is wrong in the solenoid and it needs replaced. I am not a Ford guy but if you have a metal button you push down on the top of the transmission to start the the tractor you need a ..ground activated.. solenoid as Tim shows in the upper right of his lower section of diagrams. The side terminal that connects to the activation coil internally has to be connected to the cable to the battery. If it is connected to the starter terminal it will do nothing. So upon installing a replacement solenoid and you run into this simply change the battery cables side to side on the solenoid. Secondly, as said above the button you push to start it provides a ground to the activation coil in the solenoid and magnetizes and pulls the contacts together to power the starter. If by chance you acquired a voltage activated solenoid ..upper left.. and somehow you are thinking the small red activation wire requires constant power then that is an issue you need to correct.

 

[moday]

The starter wants to turn regardless of the red wire which is push to ground. I think I got a bad solenoid or maybe the wrong solenoid. I did hook the big cables up backwards at first and had the red ground activated wire closer to the heavy cable to the starter. Maybe I damaged the solenoid. I see now that I had the solenoid upside down. My bad as I was working from memory and not the pics from Tim.

I think I need a new solenoid as step 1.

Thanks

 

[old]

Or you may have a short in the wire going to the start button and it is shorted to ground which would also cause that

 

[wore out]

If the solenoid wasn't defective ''out of the box'' of one (or both) of the copper studs turned a bit in the solenoid's plastic body when you tightened down the nuts that can jam it internally, making it conduct current whether the coil is activated, or not.

 

[moday]

I understand what you guys are saying, I disconnected the small red wire for starter push button to ground and the starter still runs when i hook up battery posts so I got a new solenoid today. Its side posts are not labeled battery or starter so do I have it correct in original photo? The small wire for the push bottom to ground should
Be closer to starter or battery lug? The photo I have has it closer to battery lug. Same question would be if the solenoid is oriented correct or upside down in the original photo. Thanks

 

[Keith-OR]

With the button down, small terminal is closer to the starter cable. I'm sitting here looking at one I took apart this morning. My new one was hanging up in the start position, so I drilled out the rivets. The quality control isn't what it used to be. I've reworked mine and will bolt it back together.
If ya hook it up backwards it isn't going to do anything as the small terminal will not be in the 12 Volt circuit, therefore won't even activate the solenoid.

Good luck

 

[JMOR]

(quoted from post at 18:48:18 09/18/22) I understand what you guys are saying, I disconnected the small red wire for starter push button to ground and the starter still runs when i hook up battery posts so I got a new solenoid today. Its side posts are not labeled battery or starter so do I have it correct in original photo? The small wire for the push bottom to ground should
Be closer to starter or battery lug? The photo I have has it closer to battery lug. Same question would be if the solenoid is oriented correct or upside down in the original photo. Thanks

ow to determine which large post connects to battery. If it clicks, you found the correct post.

 

[Keith-OR]

That is fine and good, but I am sitting here looking at the internals of a Ford solenoid and I can see which is the positive post and how activated. And the Ford tractor solenoid uses ground - to activate the solenoid, not Positive.
Did you get that method from the individual that said if hooked up wrong it would do funny things...,lol lol lol

 

[JMOR]

(quoted from post at 12:53:04 09/19/22) That is fine and good, but I am sitting here looking at the internals of a Ford solenoid and I can see which is the positive post and how activated. And the Ford tractor solenoid uses ground - to activate the solenoid, not Positive.
Did you get that method from the individual that said if hooked up wrong it would do funny things...,lol lol lol

hat was for moday. Solenoid does not care about polarity + or - is fine.

 

[Sean in PA]

Which specific solenoid (part number) did you order, and where did you order it from?

 

[Keith-OR]

I don't think it make much difference where you buy or how much it cost anymore, most of these parts come from land of OZ, if ya know what I mean. I bought what I thought was a high quality solenoid, it worked from awhile. Then it started sticking in the start position. So I drilled out the rivets, polished the end of the plunger with my deburring wheel, as it was sticking at the bottom of stroke. I put it back together with super small nuts and bolts, works fine now.
I've been repairing solenoid since the mid 60's, when your married with a family and in the military you need to save every dime you can. There is nothing inside a solenoid that is intimidating. a steel plunger with a spring, a 1 inch copper washer on the steel plunger, above the washer is a shorter spring and at the end is a smaller washer that is permanently attached.

Keith

 

[Sean in PA]

(quoted from post at 12:15:10 09/20/22) I don't think it make much difference where you buy or how much it cost anymore, most of these parts come from land of OZ, if ya know what I mean. I bought what I thought was a high quality solenoid, it worked from awhile. Then it started sticking in the start position. So I drilled out the rivets, polished the end of the plunger with my deburring wheel, as it was sticking at the bottom of stroke. I put it back together with super small nuts and bolts, works fine now.
I've been repairing solenoid since the mid 60's, when your married with a family and in the military you need to save every dime you can. There is nothing inside a solenoid that is intimidating. a steel plunger with a spring, a 1 inch copper washer on the steel plunger, above the washer is a shorter spring and at the end is a smaller washer that is permanently attached.

Keith

I wasn't asking because of the potential quality or lack thereof. I was asking to try to help him determine whether it is even the correct solenoid for his tractor. If the primary is grounded through the case of the solenoid, and he wires it the way that the tractor was originally wired for a solenoid with isolated primary where the starter button completes the circuit to ground, then the starter will always be getting power when the battery is hooked up because the primary is being grounded through the case and the starter button doesn't need to be pushed to complete the circuit to ground.

 

[JMOR]

Sean, you usually give pretty good, clear answers, but I need you to draw me a circuit on this one.
" then the starter will always be getting power when the battery is hooked up because the primary is being grounded through the case and the starter button doesn't need to be pushed to complete the circuit to ground."

 

[Sean in PA]

JMOR,

Sorry, I was basing what I said on my memory of another person who had similar symptoms several years ago and it turned out that they had an incorrect type of solenoid for the starter circuit that uses the neutral safety switch to ground the primary because the primary was grounded to the case of the solenoid. Thinking back on it, I believe that one was a 4 post solenoid.

The more I think about it, on a 3 post solenoid with a case grounded primary, the primary never could have a voltage across it if it is hooked up like the correct solenoid would be, as the small post is going to the starter switch, which is either open or connected to ground, and the other end of the primary is always grounded through the case, so the solenoid would never power the starter. Forget about the noise.

 

[Keith-OR]

Sean, with the correct Ford tractor solenoid, the primary is not connected to case ground. B+ from the battery is connected to the primary side of the solenoid. B+ is hooked up inside the solenoid via wire that is soldered to the primary , then runs through the coil winds to to starter lug inside case. when the N O starter switch makes connect to ground, circuit is then complete from B+ to neg. or as one would say to ground.

If I get time, I will draw a schematic of this simple circuit.. and post later as an update to 3 pole solenoid for Ford Tractor.

Thanks
Keith

 

[Sean in PA]

(quoted from post at 21:52:32 09/20/22) Sean, with the correct Ford tractor solenoid, the primary is not connected to case ground. B+ from the battery is connected to the primary side of the solenoid. B+ is hooked up inside the solenoid via wire that is soldered to the primary , then runs through the coil winds to to starter lug inside case. when the N O starter switch makes connect to ground, circuit is then complete from B+ to neg. or as one would say to ground.

If I get time, I will draw a schematic of this simple circuit.. and post later as an update to 3 pole solenoid for Ford Tractor.

Thanks
Keith

Keith,

Yes, I know that. I was thinking that the OP's problem was because he had an INCORRECT solenoid that has the primary grounded to the case.

Also, those old Ford tractors were originally positive ground, so they were originally wired with B- from the battery going to the solenoid and the starter switch completed the circuit to ground, which was the B+ side of the battery. Most that have been converted to 12 volts are now negative ground.

 

[JMOR]

(quoted from post at 21:52:32 09/20/22) Sean, with the correct Ford tractor solenoid, the primary is not connected to case ground. B+ from the battery is connected to the primary side of the solenoid. B+ is hooked up inside the solenoid via wire that is soldered to the primary , then runs through the coil winds to to starter lug inside case. when the N O starter switch makes connect to ground, circuit is then complete from B+ to neg. or as one would say to ground.

If I get time, I will draw a schematic of this simple circuit.. and post later as an update to 3 pole solenoid for Ford Tractor.

Thanks
Keith

o need, it is as drawn above as "Ground Activated" in the group of 6 near bottom of Tim's posting.

 

[Keith-OR]

Sean, I think he has the same problem as me. my new solenoid worked as should, but it got stuck in the starter position, I would tap on it with screwdriver handle, would work fine for awhile then stick again. So I finally took it apart and used my deburing wheel to remove small amount of material off the bottom side of the plunger. It works fine now...like I said before really poor quality control. If I hadn't worked on these before I would probably would have bought another new on.. I bought this one in July, so too late to take it back!!!!

 

[Sean in PA]

Keith,

That may be the case, but his original description said that the starter turned whenever he connected the battery, and he never mentioned turning the key once, so I assumed that something was engaging the primary without him ever turning the key once.

 

[moday]

Guys, I appreciate everyone's input. I am the original poster and I bought a solenoid that I thought was a new solenoid from a local guy that has a massive collection of old tractor Ford parts. I can say that I usually get the correct parts. I think he was a former TISCO dealer as this solenoid came in a box. With that said, the solenoid was found to be clicking when I would push the starter button on top of the trans but I could not hear that unless the starter was not cranking the engine from my earlier posts. I kept measuring a low resistance (ohm) through the solenoid meaning to me the solenoid would always provide the negative battery juice (6V) to the starter when I hooked up the positive ground at the other battery post.

I then realized if the solenoid nut for the neg battery cable was not tight, the solenoid would not flow the current. It seemed as I tightened the nut for the neg battery cable to the solenoid, a path of current flow was always present and would crank the starter. I'm tossing this solenoid and will look for a new one online.

thanks for everyone's input in this investigation! I learned alot about solenoids!

 

[Keith-OR]

moday, if it was me, I would drill the flared end of the rivets off with a little larger bit. Just to see what was inside, and maybe you could save that solenoid. But thus is just me.
Nothing inside is intimating. Just a plunger that becomes magnetic when circuit is completed by normal open push button starter switch. The only part that can be lost is the spring on the bottom side of the plunger, but it has to be pulled off.

Good luck
Keith

PS. glad ya learned few things about solenoids, AND nice that ya posted back to let us know ....Thanks

 

[Keith-OR]

Sean. on his Ford 640 the key is not even in the same circuit as the starter, all the key switch does is supply voltage to the ignition circuit, switch is either off or on NO start position..

Thanks
Keith

 

[Sean in PA]

(quoted from post at 10:25:13 09/21/22) Sean. on his Ford 640 the key is not even in the same circuit as the starter, all the key switch does is supply voltage to the ignition circuit, switch is either off or on NO start position..

Thanks
Keith

Sorry... I meant that he never mentioned pushing the starter button even once.

 

[Keith-OR]

Sean

This has been one great discussion, I have learned a few things. Hopefully others who have read this thread came away with a lot of knowledge on 3 post solenoid, that there is nothing to fear when working with the unknown. That there is nothing intimating about a solenoid, they do nothing weird or funny!!!!

Sir it has truly been a pleasure discussing all the aspects of this topic with you...

Thank You
Keith

 

[Sean in PA]

Keith,

If you're not learning something new every day, you're not doing it right.

This post was edited by Sean in PA on 09/21/2022 at 08:22 pm.