Older CK25Hst stop solenoid.

[Desert Moose]

I bought my CK12HST in march of 2007. Been great for all this time. However, it has become hard to start. Turns over just fine, just won't hit. The first few times it happened, I turned off the key and back on and it would fire up. This weekend, while using it for hours, I shut it off to talk to a neighbor. It wouldn't start, just cranked. Finally, after several minutes of poking around, it fired up. Ran fine until I parked it. Now it will not fire at all. I checked the fuel, have pressure at the bleed screw. Turning the key, I don't hear the stop solenoid pull in. Removed it, and holding it to a ground, it will not pull in when the key is turned. Pushing in the plunger and it holds retracted just fine. Just won't pull in by itself. I have checked the coil resistance on the two contacts to the case (ground). One measures 0.6 ohms, the other 15.9 ohms. So, it appears the coils are intact? Is there something else that would keep it from pulling in at the first turn of the key? Putting a voltmeter on the leads shows a brief burst to around 10.0 volts on one, and a steady voltage of around 5 on the other. (Didn't write down the actual numbers). The plunger appears to move freely, with only the spring resistance.

so, is it the solenoid after all? Even with the coils showing continuity?

Also, looking for a new one online, all that I have found have 3 contacts, not 2 like mine. Any idea where I can get a 2 contact version?

Thanks, Sam

 

[LouNY]

It could be a bad contact in a relay.
The voltage reading you are getting is an unloaded reading.
Apply a jumper to the case and connect your wiring back up,
then with the solenoid in the loop check your pull in voltage.

 

[Harry in Ky]

Are you sure you can't use one with three "contacts?" One of the three will most likely be nothing more than ground wire. You indicated yours is self grounded, yes/no? If you test your wiring, is one wire hot with key "on" and the other hot in "start"? That's how many of them work.

 

[Desert Moose]

OK, more information.
I hooked a jumper up to the contacts on the solenoid, one at a time, grounded the case on the negative terminal of a battery, and touched the jumper to the positive terminal. One contact pulls the plunger in right away, the other contact holds it in after i push it down while connected. Looks to me that the solenoid is just fine.

OK, so what relay powers this circuit? I have a wiring diagram for the CK25, but it is for a newer model that has 3 relays, start, glow plug, and hold in. My tractor has only the glow and start relays.
Does the brief burst for the pull in come from either one of these relays, or maybe from the key switch? I don't have any way at the moment to figure out where the power is coming from. Hopefully someone has a wiring diagram for a 2007 model.

Harry, you are correct, the third contact appears to be for a ground. My problem is the tractors wiring harness has a 2 contact connector. I'd have to get lucky and find a 3 contact connector that plugs into a newer solenoid, and then wire the two hot leads to the tractor two wire plug. Fairly easy, except for finding the pigtail that plugs into the 3 pin solenoid.

Sam

 

[Harry in Ky]

Well, sometimes one must get a little "creative" when dealing with things like this. Cut the connector pigtail off the old one, cut the connector off the new one, and join the two together. Make a separate extension for the ground wire (if you need it) and bolt it to something.

 

[Desert Moose]

Well, sometimes one must get a little "creative" when dealing with things like this. Cut the connector pigtail off the old one, cut the connector off the new one, and join the two together. Make a separate extension for the ground wire (if you need it) and bolt it to something.

I don't think the new solenoid comes with the 3 connector pigtail with wires. It only has the 3 pin plug on the case. Maybe I could solder some wires on the solenoid contacts and go that way if I have to.

 

[Harry in Ky]

Maybe there's something else available that will fit. Seems there are all sorts of those things out there. Can't say for sure just what, you're looking at it, I'm not. Seems a shame that Koreangineering can't supply replacement parts for more than two weeks.

 

[Desert Moose]

OK, I found a third relay, doesn't look like a relay, but with better light I found it. It's a timer relay, so might be the one to pulse the pull in circuit

Unfortunately, it looks like the part number is not to be found anywhere.

So, I'm considering a hack. The hold in circuit works just fine, it just won't pull in when the key is turned on. Since it pulls in just fine when 12v is applied to that wire, maybe I could connect that wire to a momentary push button and 12v. Then, turn on the key, bump the new switch to pull it in, and then start it with the hold in circuit doing it's thing.

Might be a new anti theft device also....

 

[Harry in Ky]

Many systems tie the pull coil to the start circuit. Engaging the starter activates the pull coil. When the starter is released the hold coil takes over. You might consider that rather than adding a button.

 

[Desert Moose]

That would be easier, I was not sure if the solenoid could stay energized longer than the original 1 second without overheating.