Fuse blows when PTO is activated

[cajunduk]

I have a 2002 Scott's L2048 and up until now, have never experienced a problem. This has to be one of the best machines JD ever built.
The problem may be multiples but . . . . my wife was mowing and stopped to pick up some limbs. The deck was turned off and the motor left running but when she tried to restart the blades, nothing happened. I ran continuity and voltage checks to all safety switches, PTO switch and clutch before determining the PTO switch was bad. Replaced the switch and energized the blades. They began to run then the 20 amp fuse blew. Figured a 12 year old fuse and running checks, etc. may have caused it to pop. Replaced the fuse, started the engine, engaged the PTO and the blades began to turn then blew the fuse again. Before I begin replacing more parts, could the clutch possibly be shorting out and if so, how can I test it before replacing.
Thanks in advance for any and all help.

 

[pugaltitude]

Sounds like clutch on way out.

You need to determine if its a clutch or tractor problem.

Are you getting a good live and earth at clutch?
Wire diagram of tractor will help.

Depends on clutch manufacturer.
usually warner or ogura.
Warner Electric

try bottom of page -turf & garden- select troubleshooting.

 

[mechanic mark]

https://www.google.com/webhp?source...v=2&ie=UTF-8#q=how to troubleshoot pto clutch Read through some of these & watch you tube. Also check wiring.

 

[bertsmobile1]

Check the wires to the PTO really carefully.
They hang out in the breeze and oft end up rubbing against a belt , Hole in the frame, exhaust ,etc,etc then they let the smoke out.

 

[motoman]

Berts, you told me a rough order magnitude "current" draw on an electric clutch may be around 8 amps. How bout a running test with a DVM inserted to the clutch feed? I guess this would require care to properly isolate and support the wiring during test.

 

[ILENGINE]

Most electric clutches when working properly should only pull about 2-4 amps

 

[motoman]

OK IL ENG so a DVM set up on current and inserted INTO the +12V line to the clutch should show about 2-4 amps. If the clutch is the culprit expect a lot in excess of that, enough to blow a 25 amp fuse...perhaps even direct ground thru failed windings? Must be running measurement? i.e., blades turning? Or static ok?

 

[ILENGINE]

Two test you can do with the ohm test with a DVM. One is attach the red lead to one of the wires going to the clutch, and the black lead to the metal case of the clutch. Any continuity and the clutch is shorted, and will need to be replaced. The other test is to put the red lead on on wire into the clutch, and the black lead on the other wire. reading should be 2.4-3.4 ohms. Above or below that replace the clutch.

 

[cajunduk]

First I would like to thank everyone for all the information and help. The wealth of knowledge and willingness to help others is what makes a forum great.
After performing all tests mentioned by everyone, I found the clutch has indeed failed, both bearings and coils, and a new replacement is on its way.
Thanks again for all the help.

 

[motoman]

Soap Box Time: the help IL ENG has shared is indeed gratifying reflecting years of experience. These tips can save people $$ if you decide not to take your 'chine in to IL ENG. Shotgunning instead of narrowing a problem, or definitive diagnosis can cost $hundreds. So I now applaud for this and other tips pro's and readers share. :thumbsup:

PS another sticky generic item we need to feature.