07 turf tiger PTO problem

[2729rdr]

It mows for about two hours and drains my battery. Voltage before starting shows 12.71 volts, when started it shows up to 15+ volts, and charging about 13 amps. When the PTO clutch is engaged, the volts drop to 12.5 volts,and amps drop to -2 amps.
How many amps should this electric clutch draw? Is there any adjustment on the clutch, or should I grit my teeth and replace it?

 

[Micah Haarhoff]

I would say your voltage regulator maybe?

 

[Rivets]

How did you hook up your meter when you tested for amperage? Negative amperage means the current is flowing in the opposite direction. If you change your leads around you should get a positive current draw. Meter must be hooked in series. In the case of a clutch, you need to break the ground circuit (lead going to ground) and attach the red lead to the terminal coming out of the clutch and the black lead to ground. Doesn't sound like a regulator problem to me, more like a bad diode if the meter was hooked up correctly. What size charging system do you have? You don't give us make, model, and numbers of the engine, we can only guess as to the cause of the problem. Throw us a better bone please.

 

[Micah Haarhoff]

How did you hook up your meter when you tested for amperage? Negative amperage means the current is flowing in the opposite direction. If you change your leads around you should get a positive current draw. Meter must be hooked in series. In the case of a clutch, you need to break the ground circuit (lead going to ground) and attach the red lead to the terminal coming out of the clutch and the black lead to ground. Doesn't sound like a regulator problem to me, more like a bad diode if the meter was hooked up correctly. What size charging system do you have? You don't give us make, model, and numbers of the engine, we can only guess as to the cause of the problem. Throw us a better bone please.

thanks I had one of mine do that and it was the regulator.:laughing:

 

[Mad Mackie]

Scag Turf Tigers have an ammeter installed on the control panel.

 

[2729rdr]

Sorry about no numbers----2007 STT61












Sorry about not enough info.-----2007










More info. 2007 STT61V-27KA Serial no.C7700422 The only numbers I can get off the valve cover is Family KAXS 745N400. To clarify how I got my volt and amp readings, I connected my volt meter to the battery terminals for voltage, and used the amp meter in the dash for amp readings. That way I could watch both meters while operating the machine.












s












v-27

 

[Rivets]

Sorry, I meant engine numbers. Trying to identify your charging system.

 

[2729rdr]

O.K. ----I went to a scag dealer today. He went into his computer, and said who purchased it in Oct 2007, and the numbers listed on the engine were FD750D 058187 hope this helps.

 

[bertsmobile1]

Sorry about no numbers----2007 STT61

Sorry about not enough info.-----2007

More info. 2007 STT61V-27KA Serial no.C7700422 The only numbers I can get off the valve cover is Family KAXS 745N400. To clarify how I got my volt and amp readings, I connected my volt meter to the battery terminals for voltage, and used the amp meter in the dash for amp readings. That way I could watch both meters while operating the machine.

v-27

Thats is good enough.
The negative reading says that the alternator is not making enough electricity to run the electronic clutch or the clutch is faulty annd drawing more power then the alternator can make.
Easy check is to disconnect the clutch and check the ammeter readings , still negative then check the wiring for holes in the insulation where you can be getting shorts.
Check the rectfrier for a bad ground and the alternators AC output voltage.

You can also check the current draw of the cutch by powering it up with some jumper cables and slpping a ampmeter into the + line.
If you are using the ammeter on your multimeter keep it down to 30 sec or less and wait 10 minutes between tests or you can fry the meter.
Most will have a draw in the 3 to 5 Amp range any more and the clutch is toast.

 

[Mad Mackie]

You need to find and disconnect the electrical connector to the clutch. With an Ohmeter, check the resistance of the coil across the two terminals in the connector. The acceptable resistance range is 2.4 to 2.9 Ohms. Then check from either terminal to a good ground, the reading should be infinity or open circuit.
There is also an air gap adjustment on three places on the clutch, the airgap should be .014" or 14 thousands of an inch.
If your clutch meets these checks OK, then you will need to dig deeper into the electrical circuits on your machine.
Parts and wiring diagrams are available on the Scag website in the operators manuals link. You will need the S/N of your machine to get the correct manual.