580 PTO wiring

[twthompson]

I have a 580 (yep yellow and white - like a 582 special). The wiring had been played with extensively before I got it. The PTO switch is not working correctly. When I pull out on the toggle and lift the switch into the uppermost position the PTO engages. When I release the toggle and the switch returns to the middle position the PTO clutch is not getting Power. Can anyone please help? I found a wiring diagram in the wiring section but it doesn't match my tractors electrical. I am ok with a hotwire type of solution but I am not sure where I need 12v to make the switch function correctly. Thank you

 

[jchamberlin]

Tim: I suspect Jonathan is correct in his assessment.

I noticed that the Model 580 has a serial number break the same as my 782; up to 719,999 uses one schematic, and 720,000 and up use another. Both can be found in the "Wiring Diagrams" off the main forum. The point is, we could do a better job of helping you if we knew the serial number of your tractor. It is found on a plate on the side of the frame on my 782 S/N 714,899.

 

[twthompson]

Jonathan and Jeremiah, Thank you for your help. Let me provide an update. My tractor is serial number 736857. I now have the above 7200000 wiring diagram and it seems to match my tractor. Maybe they are faded...not all of the wire colors seem to match the diagram. It has the wrong key switch. The one in my tractor has 5 contacts/connectors. One of them is to ground (path is the the switch case). The wires in the area of the switch have all be messed with. Everything else appears not to have been tampered with. I have two connectors on my pto switch (one with two connections and one with three connections). My switch does not have the post labeled. There is no seat switch installed. The wires are hanging (not grounding or connected). It looks like I have a reverse relay and a seat relay. They appear to be on different sides of the dash panel. I assume that the seat one is on the right side. I have a wire hanging in the area of the switch that attaches to the seat relay and the seat switch wires, based upon my ohm meter testing. I have been assuming that this is part of the issue.

Advice from anyone is appreciated.


BTW I think this all worked when I first got the tractor.

 

[jchamberlin]

Tim, it sounds like you're pretty handy with a meter and are up to the task of re-wiring the beast. The best advice I can give you is to try to put it back like it was originally, deviating only where you KNOW what will work the way you want it to.

It may have "worked" when you bought the tractor, but I'm betting it didn't work as the designer intended, only as the owner and SELLER wanted it to work. (Motivated sellers are quite inventive.)

I haven't owned or worked on a unit with relays installed, so I don't know where they are mounted on the tractor. I can help interpret the electrical prints if you don't understand how a circuit is supposed to work.

As far as your original problem in which you state: "When I release the toggle and the switch returns to the middle position the PTO clutch is not getting Power." The issue is that the PTO switch in your tractor is pulling in the PTO clutch because in the "START" position Terminal F (directly from the Alternator/Rectifier ["R" terminal at the Ignition Switch]) is connected to the PTO clutch through the Normally Open contacts of the Reverse Relay (which are closed because the Reverse Relay is energized through the Normally Closed Reverse Switch). Once the circuit to the PTO clutch is completed, the "F" terminal can drop out because terminal "B" is returning the hot wire 12 volts back from the output of the Reverse Relay contacts to through the Reverse Switch to the Reverse Relay coil. In other words, the output of the Reverse Relay to the PTO clutch is "latched in" by PTO switch through terminals "B" and "A".

If you can't follow the text description above, just trace the current through the diagram below. The first problem I would try to tackle is getting the reverse switch and reverse relay working and make sure that the PTO switch is OK. The seat switch and the seat relay serve to shut off the motor, they don't seem to be part of the problem you present, that is, keeping the PTO clutch pulled in.

Good Luck. You'll get it (eventually

)

 

[twthompson]

Jeremiah or Anyone,

I am still struggling with this wiring issue. At least I am getting a lot of wires marked

Some questions please (based upon the diagram):
1) is the PTO clutch only powered by the alternator with no connection to the battery? That is my understanding of the diagram.
2) according to the PTO switch table - with the PTO in run position there is a connection between pto switch post B and pto switch post A. I am not able to see how that provides power to the PTO clutch.

What am I missing? or When PTO post A gets powered from post F is it closing the reverse relay which then provides power to post A.

Thank you.

 

[jchamberlin]

Tim, you're missing the latch.

I tried to explain it below. I'm working on an isolated diagram and schematic that depicts the relationship more clearly, but until I finish it tomorrow or the next day (my brain is shutting down tonight), ask yourself, "What happens to the current from terminal "F" once the Reverse Relay is energized through linking "F" to "A" as well as "B"?" I hope you will realize that the PTO clutch no longer needs the switch contact from F+B+A because when the Reverse Relay contacts close (after the relay is energized) the PTO Clutch can draw its power from the Alternator directly through the Reverse Relay contacts.

Bottom Line, for me, if your PTO comes on with the PTO Switch in its momentary "Start" position, but fails to stay pulled in when the PTO switch is returned to the "Run" position, there is something wrong with either the Reverse Switch or the Reverse Relay or possibly with the PTO Switch.

Looking at it another way, when the PTO Switch is in the momentary "Start" position, it can get its power from "F" through "B". When the PTO Switch is returned to the "Run" position it is SUPPOSED to get its power from the "F" terminal through the contacts of the now pulled in Reverse Relay. If the Reverse Relay is not pulled in, the PTO will drop out. The Reverse Relay will never pull in until or unless its COIL receives power from terminal "F" through "A" AND the normally closed Reverse Switch on the transmission (or gear shifter, I'm not sure which).

It is difficult to trace out the latch circuit through the Reverse Switch and the Reverse Relay, because if any link in the chain is broken, the whole path is dead.

I've sketched out a logic diagram in Paint with my enfeebled mind which might help you interpret the wiring and the wiring diagrams.
The trouble with wiring diagrams is that they fail to communicate clearly how a circuit works.)

By-the-way, if you haven't ever seen it, Roland Bedell has a marvelous depiction of the Cub Cadet PTO switch, complete with momentary contact and color coordinated terminals in the Wiring Diagrams section of this Forum. His drawing helped me to better understand how the switch functions.

 

[rbedell]

Here is an internal schematic of the 925-0893 PTO Switch and the typical PTO Circuit.

 

[twthompson]

Thanks again for the help. There is some chance that I now have the wiring correct. But she won't start. That is because she has no spark. So my question for tonight is, could I have taken out the magneto? In my adventures I did arch across the switch a couple of times. If I accidentally put 12v on the magneto kill (shut off) wire could I have damaged the magneto? I feel certain that this is not a current wiring issues because when I disconnect the kill lead at the engine I still have no spark. I have the magnetron ignition, so no points. :-( It's good that I have a day job that does not include restoring cub cadets. Thanks.

 

[jchamberlin]

Roland, thanks for stopping by. Your drawings are superb, as always.

Tim, Jonathan is right, the only way to really tell is to tear into the tin. The magneto seems to be a frequent source of failure on these machines, and it probably wasn't anything you did. Kirk Engines, a forum sponsor (above) may be able to supply you with a replacement part if you're looking to buy something new and better than original. Brian Branstetter posted pictures of the new part installed on his wife's 782 (which is a story in itself) on the main forum, Tuesday, July 08, 2014 at 11:56 am.

My brain is a bit stronger now, and I realize the relationship between my "F" "B" and "A" contacts wasn't quite correct earlier. Since you say you have your wiring sorted out, I'm only posting the following as an exercise and an attempt to avoid mis-directing someone.

The relationship of the contacts can be depicted as follows:

When the momentary "Start" contacts are made by the PTO switch, the current flows as follows (Reverse Relay shown pulled in):

And when the momentary contact from Terminal "F" is removed, the current from the alternator continues to flow through the contacts of the Reverse Relay:

Electrically speaking, the Reverse Relay contacts (as opposed to the Reverse Relay coil) are in parallel with the PTO Switch's momentary contact at the "F" terminal. That is, the Reverse Relay contacts provide a parallel path for the current to flow once the Reverse Relay is energized. The relationship of the "A" and "B" terminals, the Reverse Switch, and the Reverse Relay coil, however, is serial. This means that a failure to provide continuity at any component means the Reverse Relay coil drops out and consequently, since the Reverse Relay contacts open, the PTO clutch drops out. That is why I feel you should check for continuity across terminals "A" and "B", across the Reverse Switch contacts, and make sure you have a relatively low resistance across the coil of the Reverse Relay. Be sure to check the coil both ways, that is, switch your leads around because DC relays are supposed to include a diode in the circuit. If the components all check out, and you're sure you have wired them correctly (per Roland's diagram), the circuit should work.

Good Luck, you're making excellent progress, I think.

 

[jchamberlin]

Jonathan, you're right. If the 580 is like the 582 it has a Briggs & Stratton engine. Brian Branstetter replaced the KT17 in his wife's 782 with a Kohler Mag 18. I was thinking of the "Mag" and looking at the electrical print, not considering the engine manufacturer. I doubt the magneto for the Kohler would interchange with the magneto for the Briggs.

Brian did an excellent job restoring the 782 for his wife, he was even able to rebuild the Mag 18, which gives me hope for my own 782 with a Mag 18 installed. The most memorable part of Brian's build, for me, was when the cows trashed the sheet metal stored in the barn while the engine build was going on. Brian posted pictures in the main forum, I think.
Cub fans are an intrepid lot, lesser men would have thrown in the towel at that point, but Brian pressed on to the finish.

 

[twthompson]

OK guys. I am back. I pulled the engine, replaced the magneto and motor is again running well and charging. I still have my original problem. When the PTO switch is in the "start" position, the PTO runs. Once I drop the PTO switch into the "run" position the PTO stops.

For sure my problem is in the relay circuit. I don't have a seat switch. I have two lose wires. The diagram shows that the seat switch is NC. Question 1 - Does NC mean with no one in the seat? If so then it would "open" when in operation. If correct. Then this is not my issue. My tractor has a manual transmission(tansaxle) with the belt clutch. I don't think I have a reverse switch?
Question 2 - do I have a reverse switch ?

THE BIG QUESTION - How can I just make this work? I promise and cross my heart not to sue.

Couldn't I add a diode some where?

Thanks to everyone for your help!!!

 

[jbaker]

Tim,
Question 1::: answer NC stands for normaly closed, NO stands for normaly open, as for the seat switch that should be normaly open; meaning a rider would close the circuit to allow startup and run and with out a rider the circuit opens killing the engine.

Qustion 2 ::: answer yes, it should of from the factory.. but sometimes people remove or jump things out

Now for my two cents,,have you tried changing the pto switch?? and its unsafe but you could jump out the safeties one at a time.

 

[rbedell]

Tim:

Ok, I made an assumption here. I thought your 580 was a hydro.

Looking into the CC Wiring Diagrams, there are two totally different diagrams for the 580, depending on the Chassis Serial Number. So, what is your Serial Number.

 

[twthompson]

Thanks guys. My first move was to replace the PTO switch. It did not solve the problem. I am using the wiring diagram for serial numbers above 720000 which is correct for my tractor. I tried to jumper the seat switch. When I do that, the tractor stops. I think I am good on that one. Thanks

 

[jchamberlin]

Tim: Please refer to the diagrams provided by Roland Bedell. The logic of the circuit is as follows:

1. If the PTO Switch is in the "START" position, the PTO Clutch receives power from the "F" terminal being shorted to the "B" terminal --no relays or other switches are involved.

2. When the PTO Switch is moved from the "START" position to the "RUN" position the PTO Clutch is SUPPOSED to receive power from the "B" terminal being shorted to the "A" terminal. That is to say, the Reverse Relay is supposed to pull in with the PTO switch in the "START" position and remain pulled in when the PTO switch is moved to the "RUN" position.

But please note that the Reverse Relay's coil can only receive power if the transmission is NOT in reverse AND someone is in the seat of the tractor.

So, summing up, the logic of the circuit is that someone must be in the seat of the tractor AND the tractor must not be backing up in order for the mower blades to turn.

Both the Seat Safety and the Reverse Safety rely upon having the Reverse Relay in the circuit, without the Reverse Relay there is no safety circuit and more importantly for you, there is no power to the PTO clutch with the PTO Switch in the "RUN" position unless the relay is used; at least that is how it was wired from the factory.

If you're not interested in restoring the original circuit's function, you are still are facing the same issue the original equipment manufacturer's faced: how to switch the PTO off and on separately from the tractor's ignition. The purpose of the PTO switch is to provide this function.

I believe that a two-position PTO switch is also available for Cub Cadets, like the one used in my early 782 and other Cubs with an electric PTO.

You could also try running the hot wire that is on terminal "F" to either the "A" or "B" lead with the wire to the PTO Clutch on the other terminal ("B" or "A") so that the PTO is switched on in either the "START" or the "RUN" position. If you elect to modify the circuit, I would recommend either disconnecting the old wires and running new ones, or make sure that only the wires you need are connected and all other wires are disconnected, in other words, disconnect existing wire to the "F" terminal and disconnect all wires into the relay, or at the very least, remove the relay from the circuit so that you don't have two wires coming from the same place and running to the same place (a wiring no-no).

Edit: Upon reading Ron's latest post (it took me two days to finish writing my post), forget about Ronald Bedell's colorful diagram, and my description of the circuits operation. You have not one, but two relays and your seat switch is Normally Closed, not Normally Open. You just have to decide whether you want to restore your original circuit's function or "roll your own." I'm going to bed. I have to be up and on my way to work in 4 hours (got 2 hours sleep last night).

 

[rbedell]

AS A TEST...

Run a long jumper wire from the battery positive ( + ) terminal to where the brown wire attaches to the Reverse Relay and see if the relay energizes and stays in.

 

[jchamberlin]

Roland is right, the Reverse Relay is the key to the PTO Clutch circuit; the Seat Switch and Seat Relay are there to shut the motor off, it simply gets it's hot wire from the Reverse Relay.

The test he suggests is to (1) find out if the Reverse Relay is working, and (2) if the Reverse Relay is working then the Reverse Switch (or the wiring to/from it) is the problem, assuming all the other wires are in place, and since it "START"s from the PTO Switch, chances are the wiring from the PTO Switch to the PTO Clutch is fine

Although the PTO Clutch could be switched directly, I would counsel against it. First, any switch you use has to have contacts rated to handle the current consumed by the PTO Clutch, including a possible shorted coil. Using a relay protects the switch as well as making it possible to include "safeties" in the circuit. At the very least, I would be sure to fuse any lead to the PTO Clutch, although it probably needs to be of the "slow blow" variety.

 

[twthompson]

I have relays on both the left and the right side of the steering pedestal. Can someone please tell me which one is the reverse relay?

 

[rbedell]

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I have relays on both the left and the right side of the steering pedestal. Can someone please tell me which one is the reverse relay?<!-/quote-!><hr size=0></blockquote>

I can't say for the 580, but IH usually put them on the LH side. It should have, WHT, BLK, & BRN wires connected to it.

 

[twthompson]

Got it fixed. Guys, Thank You very much for your help. It was the connections to the reverse relay. BTW mine is on he right hand side. Once I found it, I ohmed it out a saw that there was a problem. I could not believe how rusted the contacts on the relay were. The connector was simply not making contact with the relay. I cleaned them up and that solved it.

Roland, Jonathan and Jeremiah, Thank you very much for your help. As they say..."what doesn’t kill you makes you smarter".... or something like that.