Electrical Demons in my STT61A-27KA

[TheVirginian]

Ok, so here's the skivvy.......I bought (TRADED for, rather) a WELL used STT61A-27KA Turf Tiger. I traded BRAND NEW hot AND cold power washing equipment ( commercial, 4300psi, 4.0gpm) and was ASSURED the Scag was good to go and ready to rock. I did the test run around his yard and it started, drove, and cut perfectly. So i load it on the trailer (2.5hrs from home i drove). I get it home, unload it and make a quick pass up my side yard hill and back down and thought "hmmm, i have enough daylight i could get a GOOD portion of the field done" (the MOST of my grass, about 2.75ac of my little over 5ac, the rest is steep wooded hillside). I get to the bottom of my steep driveway and the dang thing cut off in the middle of the road. Pulled arms back and outward, set brake, SHOULD have started but nope, deader than snot...... I pull the battery, which i JUST notice at that moment has a 4/19 sticker on it (brand new at that time a month ago) and put it on charge. Yep, it was a dead (brand new) battery. Think nothing more of it, except that maybe i left ignition on all the way home? and go to cut the field. I get about 1/3 of my field done and the dang thing dies AGAIN. Guess what?!?!? Dead battery....... I go ahead and just BUY a battery and core that brand new one in exchange and get another 1/3 of my field cut and it died again. I take the battery out and go charge it again and bring a voltmeter with me this time to try and figure out is it the regulator/rectifier or WHAT is going on that it's killing the battery so fast?!?!? Well, guess what? now, the dang key wont even turn and i king kong'd it a little and it DID turn but broke internally (not the key, the ignition, lol, oops?!?!?).

So, i get a new ignition switch in, and bought a new regulator/rectifier, and went ahead and bought a PTO knob replacement, and the relay in there as i got ALL that for less than $50 and it was a GREAT place to start.... I put the ignition switch in first, and then the regulator/rectifier. NOW, it starts fine (haven't actually checked charging or not yet, because.....) but as SOON as you engage PTO knob, blows main fuse.........I put two new inline waterproof fuse holders and fuses in, still same..... So, i put NEW PTO knob on, and relay, and a new fuse and try again. SAME THING!!! I talked to my local shop (also a family friend) and he's saying wire harness is burnt/faulty somewhere and/or electric PTO is kicking out too much voltage. I now have BOTH of those in my possession ($500+ dollars later......) but I wanted to see if anyone else here has had a similar issue with their 27hp Kawa and 61" turf tiger setup? I'm not sure even though it SAYS it's the same part number, that the regulator/rectifier is the right one. Just because it looks like it, and has same plug/pin connection, doesn't mean it was wired INTERNALLY the same to those pin designations, or am i just over thinking that? Thanks in advance for any help provided.

 

[Luffydog]

Check the charging first make sure it is. Then check the clutch ohms not sure which one is on your machine but should be between 2.3-2.8 somewhere in that range if below is or above is bad but just because it is between those numbers doesn’t make it all good. It still could be failing at times. It should be tested at cold before start up. If that test doesn’t seem to help with the numbers do a amp draw test for better numbers. If your mowing about a hour to 1.5 hrs and then it quits that’s about what time it would take to drain the battery if clutch is drawing to much amps or less time depending also have to add the fuel shut down solenoid in there as well. Keep us posted.

 

[TheVirginian]

Cool story bro! now can you say it in English? (just kidding man, but you totally lost me). I'm pretty mechanically inclined and know very much how to use a DVM but knowing WHERE to test (which connectors), what to test (which pins should be "hot" or just ohmed), and what not on this Scag is totally foreign to me. I have looked at the wiring diagram in the manual but i think someone has changed some things in this wiring system. I KNOW for a FACT he defeated the seat safety switch but i've noticed some other wires that are supposed to be a certain color via the diagram but are NOT that color in reality on MY machine. I have the new wiring harness, i may just do that (unless i find it's over my skillset which it shouldn't be) and see where we are from THERE on electrical system because i feel like i'm chasing MULTIPLE demons in this electrical system while trying to just narrow down ONE.

 

[TheVirginian]

Forgot to add, one of the main reasons for going ahead and making the purchase of the wire harness was when i replaced the ignition switch i saw some of the female connections of the harness plug were burnt/melted looking slightly. I forget if it was the PTO harness plug or that one but one "corner" of the plug was malformed slightly from heat/partial melting but still fit "snug" against the component otherwise. I am SO mad that this guy did me this way over this machine, when what i traded for it was brand new condition and perfectly operational. hard lessons learned..........

 

[Luffydog]

Unplug the clutch wires and check just the clutch itself for the ohms test. First check the ground cable on battery and on the motor as well as you could just have a bad ground. Then check charging. Then the ohms test with clutch unplugged put your volt meter leads the to wires from the clutch no power needed for the test.

 

[TheVirginian]

Thank you sir, i will give it a go tomorrow. TOTALLY unrelated to THIS forum but made a post in the proper one but i want to pick YOUR brain while here in case something triggers a suggestion....... have a Craftsman PYT-9000, 26hp B&S Professional Series that the left (of 3) mandrel broke on last summer. Since the scag was down and the grass is getting STUPID tall i dropped the bucks on three new spindles to have SOMEthing to cut with til the Scag is right. I get them replaced no probs. Since mower sat since last summer, even though it JUST had had an oil change and new air filter put in 2 cuts before that, i checked all that, blew out air filter, greased all the zerks i could remember and could find, put a battery in it and tried it. First turn of key, just a "bump" and slight rotation. 2nd turn, same thing. 3rd turn it fired RIGHT up and ran STRONG but i'd only put 2cups or so of fuel in freshly drained and blown out gas tank and fuel line, in case it didn't start, or didn't run right so i didn't waste/taint fuel. Since it worked fine, i filled it about halfway, climb back on seat and NOTHING, i mean no dummy lights, no hour meter, no headlights when key is on and NOTHING when you turn to start it....... did the ignition switch burn up? I'm going to check ground on that as well to the frame but it got dark on me. Just baffled how it was there, and worked FINE and by putting GAS in it, it now is totally dead to the world..........LOL. I can't win for losing bro.........very frustrated at the moment.

 

[Luffydog]

If no power at all check the fuse. Then check oil. Then check make sure it’s not over filled if so make sure it doesn’t have gas in the oil. Sounds like might need the valves adjusted if you don’t find gas in the oil and battery is good then I would move to taking the plug out staring over a few times makes sure no fuel is I cyclinder to cause hard start then go to the valve adjustment if needed. Might have blown the fuse from the hard starting or holding the key for to long trying to start it. Check for power first battery fuse then the others as posted above.

 

[Luffydog]

If no power at all check the fuse. Then check oil. Then check make sure it’s not over filled if so make sure it doesn’t have gas in the oil. Sounds like might need the valves adjusted if you don’t find gas in the oil and battery is good then I would move to taking the plug out staring over a few times makes sure no fuel is I cyclinder to cause hard start then go to the valve adjustment if needed. Might have blown the fuse from the hard starting or holding the key for to long trying to start it. Check for power first battery fuse then the others as posted above. Check all wires as well make sure not touching to cause the sudden short.

 

[TheVirginian]

Yeah, i'm in process of trying to find out if there IS a "main fuse" on this Craftsman. It's not in an obvious spot if so. I'll post any updates i come up with good or bad. Thanks for the advice

 

[bertsmobile1]

There is one, told you how to find it on your other thread.
If this mower has been sitting all winter it is advisable to pull the blower housing & check for mice nests.
They have a habbit of making midnight snacks on the wiring insulation.
In particular the power wire that goes to the fuel solenoid which usually runs across the top of the engine.