Toro - PTO - Blows Fuses

Discussion in 'Mechanic and Repair' started by srefird, Sep 6, 2004.

  1. srefird

    srefird LawnSite Member
    Posts: 8

    I have a Proline 44" cut and it has worked great for about 4 years. Now, evertime I energize my pto, within 3-5 secs the fuse blows and the blades cut off. This system does not have a battery.

    I've checked the PTO for a short to ground. (none)
    I've pulled it off to inspect and to recalibarte. (complete)
    I've inspected all wireing for any shorts or frayed wiring. (none found)
    Have replaced the "black box" module that does God knows what. I'm assuming it is a voltage regulator. (complete)

    I have not yet replaced the blade engagement relay.
    I don't see how that relay can be causing a the fuse to blow.
    But that is about all that is left.

    It seems to me that the unit is cranking out more power than the pto (fuse) can handle.

    Any suggestion would be appreciated.

  2. kkat

    kkat LawnSite Member
    Posts: 62

    you have a short someplace
  3. srefird

    srefird LawnSite Member
    Posts: 8

    Man .. I figured ... I just can't find it .. about to wear my ohm meter out .. that system doesn't look that complicated or I'm more brain dead than I thought.
  4. Oldtimer

    Oldtimer LawnSite Bronze Member
    Posts: 1,458

    Ohm out the clutch. What does it read?

  5. fixer67

    fixer67 LawnSite Silver Member
    Posts: 2,100

    Check the wires RIGHT AT the point they go into the clutch casing. I have seen them ware bare spots in them and ground out with the housing and each other. You have to look real good to see the damage if it is even there because the wires go in the top and that is no fun. Take a mirror and you may be about to see on top of the clutch. You do not want to take that clutch off unless you are 110% sure is is damaged because can be a real PITA to get off and may have to be destroyed to come off
  6. srefird

    srefird LawnSite Member
    Posts: 8

    It was a near short ... 2-3 ohms as I recall ... since it is a coil that is pretty much what I would expect it to read.
  7. srefird

    srefird LawnSite Member
    Posts: 8

    I didn't have to much trouble taking it off and putting it back on .. I did that a couple of days ago for the exact reason you stated ... I could not see those wires. I took it off put it on my bench and looked over it real good .... even went so far as to wiggle my ohm meter leads into each slot where the wires go, expecting to find a short from one of those wires to ground (the casing) but got nothing.. so I cleaned it up and adjusted it per the specs. and remounted it. Even decided to add a new drive belt since I had to remove the old one any way.

    Can the magneto be cranking out to much power? Do you know what regulates how much juice it can crank out? I'm wondering if I'm looking at the wrong place.
  8. Oldtimer

    Oldtimer LawnSite Bronze Member
    Posts: 1,458

    Replace the field coil. Should read 1.8 max.

  9. srefird

    srefird LawnSite Member
    Posts: 8

    I think you're right .. I overfused from 7.5a to 10a and got some of my grass cut last week. We got about 6" of rain from the storm that came up from your area and had some major grass to cut. Today I went back to work on it and it seemed to be working fine. After about 1 1/2 hours, the 10a fuse blew. I replaced it and mowed for about another 15 mins and she blew again. I disconnected my wiring harness to the coil and ohmed it again... reading about 1/2 ohm. The users manual (which is pretty slim) does have it listed as a 3 ohm coil.

    Can you tell me where to get another? Besides the dealer. Is there a heavy duty after market brand that will last longer?

    Appreciate your advice and any other recommendations.

  10. Oldtimer

    Oldtimer LawnSite Bronze Member
    Posts: 1,458

    The field coil isn't that expensive and is only available from Toro as far as I know.

    Keep the clutch adjusted, engage the blades at the slowest engine speed possible and disengage the blades at idle.

    Adjust the belt tension springs to exactly 5 inches from the washer to the carrier frame bracket.


Share This Page