318- PTO Dropping out .....again!!!!!

Scotty370 · Oct 10, 2011

I've got a vintage (Late 80's 318) I had problems where the Electro-Clutch would not, engage. I did the 'Air-Gap' adjustment, and that helped. Lately I've had starting problems and had to recharge repeatedly! Finally this weekend, I replaced the (11/06) battery with a 'beefy' Exide! Fired and ran fine...............for awhile! Then the mower stopped just like I'd broken a belt! PTO Light ON, but no blade movement! I cycled the switch, and it would come back to life.........for a short time. Is this a symptom of the Electro -Cluch again? I also replaced the 'finned' module (rectifier?) and that seemed to help for a while, but now my battery light is back on, even with the new fully charged battery. I'm wondering if it's blown again. The battery as I said is new!!! I can't figure two things: Why is the mower PTO Dumping on me and what's with the Charging Light? Thanks in advance. ~Scotty

David_Kb7uns · Oct 12, 2011

Neighbor has a 420 and one day he had to jump it to get it going and figured nothing was wrong, he was incorrect. With those clutches pulling around 7 amps a piece and having to run the coil and charge the battery their is quite an electrical load. You may have a magnet with a short developing when they get hot, too much run time with improper air gap will burn out the windings. See if you can get the spec from Deere on the current.

If you replaced the regulator, make sure it is the higher rate one. You will also need to check the fuse holders and also the ignition switch as they go bad. Some of the ignition switches switch the battery charge lead so if that is bad no charge. Also check the windings on the stator for a short to ground, some engines had a seperate circuit for charge, lights, and clutches

Cannot remember the safety circuit, but there is circuit on some of the seats to kill engine when pto engaged and bad switches can be a hard problem to find.

A service manual with schematic whould help you alot.

David Kb7uns

Jim Thompson · Oct 12, 2011

If I recall correctly, those engines were shock mounted and and frequently had problems with maintaining a good ground between the eng and chassis. Check all of your ground straps. Also insure that the regulator has a good ground.

Jim

Wayne_H · Oct 13, 2011

You are talking about two problems....

The finned device you replaced sounds like the voltage rectifier/regulator. If that goes bad, the yellow charge light will never go out. But, since they cost almost a hundred bucks, measure the voltate on the center pin, it ought to be 13.8 or so. (As I recall, the two outside pins are the AC) Could be the connection from the regulator to the fuse and circuit that turns that light on/off, so see if it is charging first!

The PTO still sounds like a clutch adjustment. What is the clearance you set it to? (This is sort of a quiz....) If it is too much, it won't stay engaged, and when hot it won't ever engage. The only problem I've seen with these is the adjustment is out of whack. Set it like 0.014" or so.

Wayne

Scotty370 · Nov 6, 2011

Will that Rectifier/Regulator, get 'fried' if I Jump-started the tractor? (And I have.) I've still got problems! The "Charge-Light" is still on, and the PTO Clutch 'drops out' when it feels like it. I can get a new Rect/Regulator for $29.00 0n E-Bay, but really don't want to just keep 'throwing parts at it"!! !Scotty