• Online Events For Landscapers!
    With GIE+EXPO cancelled, virtual education and product launches are filling up the fall. Check out dates for Caterpillar, Exmark, NALP, and more. Click here to learn more.

Gravely Promaster 20H Blown Fuse

neversink

LawnSite Member
Location
Shillington, PA
Fuse between the ampmeter and hot side of the solenoid will burn out after 15-20 minutes of mowing. Then, it will blow a new fuse within minutes if you replace it immediately. Any ideas?
 

Restrorob

LawnSite Fanatic
Check the positive power lead (red) on the back of the ignition switch for rust/corrosion. If rusted the contacts inside are most likely burnt/shorted, Replace the switch and red connector.
 

fixer67

LawnSite Silver Member
Location
Tryon NC
Also check the fuse holder. If the holder has rust/corrosion it may not hold the fuse tight and cause it it heat which will cause it to blow at a lower amp load than it should. A 20 amp fuse can blow at 10 amps if the fuse gets hot. This is called "cooking". When a fuse cooks it damages the holder even more until it is totally useless.
 
OP
N

neversink

LawnSite Member
Location
Shillington, PA
All connections are rust free. The fuse size was a 20 amp fuse. I bought this mower used, so I'm not sure of the fuse size for sure. I have tried 15, 20, 30 amp fuses. I can't find a wiring diagram for this ZTR mower
 

Bill Kapaun

LawnSite Senior Member
Location
Albany, Orygun
Did the 20 & 30 amp fuses take the same amount of time before they blew?
What I'm thinking, is IF they did, it's a heat related issue. Something starts drawing excessive current when it gets hot or something "moves", causing a short. Just what "heat related issue", I don't know.

DOES the ammeter start showing increasing current flow before the fuse blows?
 

Restrorob

LawnSite Fanatic
I can't find a wiring diagram for this ZTR mower
If I had full model and serial numbers off this unit there's a good chance I may be able to drum up one.

Does this one have the Kohler or Onan ?
 

Restrorob

LawnSite Fanatic
Here's the wiring diagram.....

You may try by-passing the ammeter by connecting the pink/black and white/black together, I have seen ammeters short out.



 
Top