blowing fuses

[RandyT]

Had an interesting lawnmower problem come into the shop today. Kept blowing fuses. Owner claims he started it about two days ago and no problems, and this time he hit the key and it blew the 20A fuse to the whole mower.

Put a new fuse in and unplugged everything to try to isolate the short and got everything plugged back in and still didn't blow the fuse until I tried to start the engine and the starter turned but gear didn't engage the flywheel. After that couldn't get anything to response even with different fuse.

Now the interesting part I decided to check the battery voltage and put the red lead of meter on + and the black lead on - and the meter read -11 volts. The battery has reversed polarity and was trying to turn the starter backwards which is why it was blowing fuses.

 

[Jim32]

Randy, check the wiring on the electric clutch PTO. Sometimes the insulation on the wiring will wear off and the bare wires will short to the frame. I had this problem. I insulated the wires with electrical tape, then replaced the fuse. No more problems.