Repairs Turf Tiger PTO issue

CB61

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I have a Turf Tiger SST/61A serial # 545xxxx with 25 HP Kohler. Replaced the PTO clutch less than a year ago (it was completely worn out), PTO switch, and recently the ECM. I was having a previous issue with the PTO switch not engaging. I have checked all safety interlocks and they are fine. With the engine running I can engage the PTO and the voltage on the light blue wire from the ECM goes from 12+ to 0. I assume the light blue wire is what actually energizes the PTO clutch. I can bypass the PTO switch with a toggle switch and the clutch engages immediately so I am confident it is not the clutch or wiring to it. Is this likely a poor ground? Any ideas?
 

Luffydog

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Yes it could be but other issues as well. Wiring harness might have a short to. Fuse holders might be worn out from heat because current creates it. But yes could be a bad ground. How is the battery? Check ground at battery and engine. How is the charging? What does the fuses look like? Why would you want to bypass the pto switch? Is it burning the pto switch out? If so I would check charging and the clutch.
 

CB61

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Yes it could be but other issues as well. Wiring harness might have a short to. Fuse holders might be worn out from heat because current creates it. But yes could be a bad ground. How is the battery? Check ground at battery and engine. How is the charging? What does the fuses look like? Why would you want to bypass the pto switch? Is it burning the pto switch out? If so I would check charging and the clutch.

Fuses/holders are good. Battery was purchased last year and is excellent as is the charging system. Bypassed the PTO switch as a last resort to get the mower to work. PTO switch is good also.
 

Luffydog

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Why did u bypass it by add the switch. I guess what I am want to know what is not working when you put it back to the way it supposed be. Won't start,will start,start but when u pull pto it dies,when running awhile it does,guess I am looking for little bit more info. There is some simple test you can do to determine what might be wrong with using a test light. Give us little bit more info and we will go from there. Thanks
 

CB61

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Why did u bypass it by add the switch. I guess what I am want to know what is not working when you put it back to the way it supposed be. Won't start,will start,start but when u pull pto it dies,when running awhile it does,guess I am looking for little bit more info. There is some simple test you can do to determine what might be wrong with using a test light. Give us little bit more info and we will go from there. Thanks

What does not work is the PTO will not engage. Just figured out that the PTO switch is bad. That is two PTO switches bad. I checked the wiring and it has 0 resistance on the blue wire from the PTO switch to the clutch. Also 0 ohms on the ground circuit. I did clean the ground connection on the chassis anyway so that should not be an issue. I put a new clutch in last year but was having the PTO issue prior to that. Still, I am wondering if this clutch has an issue. The PTO switches I used were not from a Scag dealer/supplier and could they not be heavy enough to carry the current. I understand the PTO circuit carries about 3A-6A.
 
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Luffydog

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Take a battery reading then crank it up and take another reading see what it charging at. Then take the meter unplug the clutch. Set your meter to ohms. On the clutch wires check the ohms thinking the reading should be 2.5- low end and no more than 5.5 or so on the high end but I will check out and post back shortly to be sure of the reading. On the ohms clutch.
 

Luffydog

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Just looked it up to be sure. Gt1/gt1a/gt2=2.8-3.2 ohms and for the following. Gt2.5/gt3.5/gt5=2.0-2.4 ohms. Also can do the amp draw test as well but the ohms should put you in the park. Just remember the readings will change after be hot meaning that it could show good with ohms and failing after being under a load with the temps being up.
 

MontecarloSS

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Just a thought have you checked the gap on the PTO to be sure it is in specs?
 
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