Mower Deck engage problem on Toro ZTR

TallMinnesota · Jun 5, 2013

I have a Model 74204 Toro ZTR with 500 plus hours. I know my battery needs to be replaced but I jumped it and it starts and runs fine. It suddenly started to run very rough while mowing. I disengaged the mower deck and it runs fine. I tried to reengage the mower deck several times and it would not reengage. After shutting down the mower and jumping the battery again it started and the mower deck will reengage. I am not sure about the electrical part of the Clutch part number E631732 (costly item) and the switch part number 103-5221 (old part number E633673). What might be causing the problem? I replaced both ignition coils last year and the engine idles and runs fine.
Thank you, Bill

sox3 · Jun 5, 2013

Need to test Battery and charger / output system. unit may not be putting out enough power to run electric clutch. Just wondering why you had to replace both coils?

TallMinnesota · Jun 5, 2013

Thank you for the reply my guess is you are exactly right about the battery. I did not understand the "electric clutch" concept and I will charge the battery and see if it discharges and the same problem reoccurs.

I replaced the coils when I started having problems with a fouled spark plug and rough running engine. I assumed it was a problem with the coil and took it out and had it tested. It was dead or close to and the tech, who I trust, suggested I replace both as the new and old coil will put out different levels of spark power. I agreed as I had the shroud off and OEM coils were only about $37 apiece. The mower ran great for the rest of last summer and fall and initially this spring but I imagine the battery sitting in an unheated garage over the winter in Minnesota may have killed it.

Thanks again for your reply. Bill

TallMinnesota · Jun 5, 2013

If the battery doesn't charge is it possible that the Rectifier (Part number 2540303) needs to be replaces? Is it the rectifier that causes the battery to be charged when the engine is running?

Thanks

sox3 · Jun 5, 2013

If you have a volt meter you can test to see if getting charge voltage. I believe that unit has a dual system in it. The other system will power the clutch. There is also an interlock module on it too.