Blowing fuses with key off

[PTmowerMech]

Troybilt Super Bronco 13WQ93KP011
Kohler KT735-3012

Replaced fuse, and blew immediately. Removed the + battery cable and replaced it again. Blew as soon as I reconnected the battery
Removed the voltage regulator connect, replaced the fuse (ran out of 20's, used a 25) Plugged the regulator back in, reconnected the battery, and it's all good.
Except the lights wouldn't go off. And the engine wouldn't start. So, I tested the key switch and it's bad.

So my question so far is, could the key switch be causing the short that's blowing the fuses?

I still haven't checked the regulator yet. I'll get to that when I get the switch replaced.

 

[slomo]

Replaced fuse, and blew immediately.

Something is drawing too much current.

Removed the + battery cable and replaced it again. Blew as soon as I reconnected the battery

Well it's not the + cable right?

Removed the voltage regulator connect, replaced the fuse (ran out of 20's, used a 25)

Um, not advised to install a higher amp fuse, even for testing. Again you have excessive amp draw.

Plugged the regulator back in, reconnected the battery, and it's all good.
Except the lights wouldn't go off. And the engine wouldn't start.

All good is no further issues.

I would disconnect items kinda like you are doing. One at a time reconnect and see when the fuse blows.

Probably the regulator has shorted on you. Maybe some crazy diodes.

Make sure the blades are off. PTO might be drawing excessive juice.

 

[Rivets]

Yes a bad key switch can contribute to the problem, but you’re going to have to do some electrical troubleshooting to make sure.

 

[Hammermechanicman]

When troubleshooting blowing fuses take a blown fuse and a light bulb socket and cobble it together so the fuse link is replaced by the bulb. You plug this into the mower fuse holder and if you have a short the bulb lights up. When the bulb goes out you have found the short. Saves replacing lots of fuses

 

[bertsmobile1]

Are you 100% sure the battery polarity is right way round ?
pull the PTO pug apart & pull the plug off the back of the key switch
Check their power wires for a ground short
Pull the rectifier plug off and do the same
Plug them back in one at a time
One of the three will pop the fuse or light Hammers lamp
FWIW I use plug in circuit breakers for the same reason .
They will not take long term use in the mower but are good for short term testing

 

[PTmowerMech]

Are you 100% sure the battery polarity is right way round ?
pull the PTO pug apart & pull the plug off the back of the key switch
Check their power wires for a ground short
Pull the rectifier plug off and do the same
Plug them back in one at a time
One of the three will pop the fuse or light Hammers lamp
FWIW I use plug in circuit breakers for the same reason .
They will not take long term use in the mower but are good for short term testing

yes, the battery cables are on right. I checked that when I was fishing around for the fuse. (in the back, under the battery)

I'm waiting on a new switch. This was is bad.

 

[Hammermechanicman]

Are you 100% sure the battery polarity is right way round ?
pull the PTO pug apart & pull the plug off the back of the key switch
Check their power wires for a ground short
Pull the rectifier plug off and do the same
Plug them back in one at a time
One of the three will pop the fuse or light Hammers lamp
FWIW I use plug in circuit breakers for the same reason .
They will not take long term use in the mower but are good for short term testing

The nice thing about the light vs a breaker is that you can troubleshoot the high current draw with it powered on. A breaker will trip out like a fuse whereas the light provides enough load to to not trip or blow. You can disconnect and reconnect things until the light goes out.

 

[bertsmobile1]

Just depends what works for you.
I got a grab pack of blade breakers cheap and usually I can hear them pop
Being only slightly bigger than a fuse they fit nice in the tool box and of course I have them from 1A to 50A
SO I double checked what proports to be the wiring diagram
With the key off the only things connected to power is the key switch & the rectifier . looks like the PTO gets it's power from the A 1 key terminal
So that only leaves you with the 2 possible sources of the short ( and of course the wires between them.

That particular switch has 2 ground terminals the G & L, L being used for the MIR function
So yes a very good chance that a bad switch could be causing the fuse to blow.

Sorry that I did not read your original post properly
When I have a suspect key switch , I pull th plug and make the connections with some jumpers , short wires with uninsulated male blade terminal both ends
If it runs fine hot wired then the switch id suspect
You can get lots of silly things that can short out a key switch from corrosion to ants
The wiring diagram with key switch connections is in the parts book or in my case on the ARI data base so all of the usual parts suppler s web sites should have it on line
Some times it is just a bit of corrosion on the back of the plug a well that can be making the short s

 

[PTmowerMech]

Just depends what works for you.
I got a grab pack of blade breakers cheap and usually I can hear them pop
Being only slightly bigger than a fuse they fit nice in the tool box and of course I have them from 1A to 50A
SO I double checked what proports to be the wiring diagram
With the key off the only things connected to power is the key switch & the rectifier . looks like the PTO gets it's power from the A 1 key terminal
So that only leaves you with the 2 possible sources of the short ( and of course the wires between them.

That particular switch has 2 ground terminals the G & L, L being used for the MIR function
So yes a very good chance that a bad switch could be causing the fuse to blow.

Sorry that I did not read your original post properly
When I have a suspect key switch , I pull th plug and make the connections with some jumpers , short wires with uninsulated male blade terminal both ends
If it runs fine hot wired then the switch id suspect
You can get lots of silly things that can short out a key switch from corrosion to ants
The wiring diagram with key switch connections is in the parts book or in my case on the ARI data base so all of the usual parts suppler s web sites should have it on line
Some times it is just a bit of corrosion on the back of the plug a well that can be making the short s

I was looking at those on Amazon the other day. I think I'm going to start investing in some of the more popular sizes. But the lightbulb idea is pretty good too.

 

[PTmowerMech]

Update, I found a key for a used key switch I had, and replaced the old one. And so far, so good on the fuse.

Oops, I just remembered, I still have that 25A fuse in it.

Man this mower has a bunch of issues. The PTO isn't clicking when I pull the button. Got down there to check to see if it was getting power, and there's no PTO stop on it. The only thing that was stopping it was the hard plastic harness where the wires go into the PTO. LMAO..

Customers request when he dropped it off. "I don't want to put much money into this." smh