520H - 25 amp fuse pop when on / before start

[Mt Zion 520H 43]

So.. Another issue presents itself. Been googling and reading quite a few posts about this issue but haven't really found a reason or fix. Maybe i need a break and more sleep.

Posts mention a lot of issues can be caused by the pin connector and fuse box being dirty or corroded.. Can this cause the 25 amp fuse to blow when key turned before start? Or is only cause for this being a short somewhere? I thought i fixed it when i sprayed them with electrical cleaner.. But not long before it went again.

I burned several fuses the other day.. Even ran a 10amp in the slot before it pop'd too. It's intermittent and i'm unsure if it's movement or time/strain (heat generating) that's causing them to blow.

Anyone dealth with this and figured it out?

Edited August 5, 2017 by Mt Zion 520H

[R. L. Addison 299]

I would guess you have a bare wire going to ground somewhere in the system, Does it do it only when mowing? Does it blow only when driving? Does it happen when you move your feet, or bump the dash?  I would start it and wiggle wires where they go through metal and behind the dash, look for dark spots in the wiring, especially around the dash/battery charging systems and where it could come in contact with metal. Intermittants can be a challenge. Pay particular attention to the ignition switch. 

[Mt Zion 520H 43]

It's weird. It popped while mowing and while just riding and while stationary. While still.. After popping just by turning key.. Not to start.. I could remove and replace and pop again. If i went to find another fuse or pulled one from another slot or went to find another to put in.. It sometimes would not pop immediately. Then i'd get to start it and it would run until it pops again without riding.

 

There are some exposed wire but touching nothing. Looks like po had issues and tried tracking and rsolving. I've had it less than 10 months now and used less being in PA.

Edited August 5, 2017 by Mt Zion 520H

[ericj 1,578]

check voltage regulator, I had one short out and cause the same problem as soon as the key was turned on. If the voltage regular doesn't see 12 volts it can and will short out. That's what happened to mine and I didn't realize the fuse was bad till it blew the fuse. That's been a few years ago so I don't remember all of the particulars. Good luck

 

 

 

 

eric j

[gwest_ca-(File Mod) 11,254]

Sounds like your problem is in a circuit that is powered in the RUN position which is most of them. You can follow them by studying the wiring diagram for each circuit.

Look for a flat area worn on one side of the insulation on each wire where it could be rubbing on chassis metal from vibration. It is hard to see. The one that will give you a short will have a thin line along the center of the flat worn area. That line is bare copper and enough to cause a short. A wire too close to the steering shaft is a common problem area.

 

If you get to the point that the short is constant you can leave out the fuse and connect a test light across the two terminals the fuse plugs into. One side has battery power and with the other shorted to ground it will light the test light. Keep in mind anything that that circuit normally powers is also a load so it will also power the light. But if you disturb the short the light intensity may alter giving you a clue to it's location.

If it does not show up disconnect say the ignition coil so that load does not trigger the test light on and so on. Anything the 25 amp fuse is powering. Those items are identified by the 25 amp fuse in the individual component diagrams.

 

Like looking for the proverbial needle in the haystack but they can be found.

 

Garry

[953 nut 58,024]

I have found that if you replace the fuse with a 12 volt test light while looking for a short you will see the light (no pun intended) when you find the short. Need to have power to the circuit for this to work.