MTD colt PTO clutch.

[Gerry]

Working on a MTD ZTR and electrical is driving me crazy need help!!!! Model num: 17WF2ACS011 DOM: 02/02/2011. The PTO will only come on randomly. Let it sit and cool down and still will not engage. When running the unit is delivering 13.4 volts to clutch. When shut off 12.6 volts, sometimes nothing. I have checked the following safety switches both neutral, both forward controllers. I did not remove the brake switches but I pulled the wiring harness connectors put in a new switch and did a non run test and the clutch was clicking. Started engine and blades would not energize...……..thud.

Owner said he installed a new PTO switch, I did continuity check on it to tested good.


When I did clutch Oms test I got 3.3/3.4 cold. Checked when hot and I got 9.7.


TIA.

[KE4AVB]

Depend on you reading the ohmage for the PTO clutch coil it does sound like you have a failing coil winding. As the resistance increase the current drops thus the magnetism drops causing the clutch to become inoperative.

Also check all the electrical terminals associated with the PTO circuit as I have seen the F56 terminals spring to become weak and/or break causing lost of contact.

[38racing]

I have a burned out MTD zt50 in another thread. Just been studying wiring as no schematic in ipl. Found a service manual dated 05 but it has 3 relays that I dont have. One is pto and one is seat. Problem at either one might cause pto to cut out. Manual is 769-01421.
This link might get it
https://www.manualslib.com/manual/74746 ... ro-17.html

[KE4AVB]

38Racing since you finally note the model series the following for the later Zt50 is the wiring setup you may have.

https://i.imgur.com/ar9fmvu.png

[38racing]

38Racing since you finally note the model series the following for the later Zt50 is the wiring setup you may have.

https://i.imgur.com/ar9fmvu.png

Pretty much it. I just notice that the one posted shows two brake switches to achieve NO,NO,NC. Mine has this brake switch 725-04232 Switch, 3-Pole, (NC-NO-NO) - Brake which survived the fire.

[Gerry]

Just an update, it was the left side lever safety switch part num: 725-04363. I tested it the fist time it would pass but on the 3rd and 4th consecutive test it would fail.

[38racing]

Interesting. The mtd zt50 that I just rewired didn't have switch like that. Clutch safety was through single poles on reverse on each side. As I just posted in the other thread that my initial testing failed because the switch on left would not close. Where is that double pole actually located?

[38racing]

I downloaded your manuals and again no schematic. Not sure why mtd did that. On the reverse switch are both poles actually used? I don't see any relays for you either . your brake switch is the same double pole where mine is 3 pole. Description of safety systems on yours matches mine.

[38racing]

38Racing since you finally note the model series the following for the later Zt50 is the wiring setup you may have.

https://i.imgur.com/ar9fmvu.png

So I just looked at this again and it appears that they use a double pole switch on the reverse but only actually use 1 of the poles. It is a screw on mount. My single pole snaps into an adjustable bracket. I'm pretty sure there is a single pole screw on that they could have used.