Deere 4100 blows starter/glow plug fuse when pulling pto switch

coloradotrout · 2025-09-29T23:33:15-0400

I had been mowing for an hour when it suddenly died. No dash lights, nothing. I found that the 10A fuse was blown. I replaced it, started right up, but when I engaged the PTO switch, the fuse blew again. Later I installed a 7.5A fuse and mowed for about 30m before the fuse blew. Hydraulic fluid is at minimum on the dipstick. I do have a leak at the fitting attached to the pump. The finish mower was working hard but not stalling.

What can I check?

coloradotrout · 2025-09-30T09:02:43-0400

Another thread noted there are 3 solenoids that may have bad windings. The first time I replaced the fuse it only ran for a few minutes after pulling the PTO switch. The 2nd time it ran for nearly 30 minutes before that fuse blew.

coloradotrout · 2025-09-30T09:59:32-0400

John Deere 4100 Blowing 10 amp Fuse when PTO Engaged

I think may be your direct shorting a wire with movement also as it happens after your started and moving. My shop manual shows all these circuits (HST) are protected by the F2 fuse BR1& BR2 terminals on key switch Glow plug module Glow plug relay Fuel relay PTO switch PTO relay Fuel gauge...

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