LX176 Not Cranking - Need help!!

grenneam · May 14, 2015

Hi. I've got an OLD LX176 with a 38" cut that has been wonderful until a couple of days ago while I was cutting the lawn. Everything was going good then the cutting blades stopped turning and I couldn't get them going again. The motor was still running so I drove it to my garage and shut it down to give it a break - thinking maybe something over heated. After an hour or so I went out to see if the problem had disappeared and found that I had "bigger problems". The Engine would not crank at all. I figured maybe the PTO switch was causing the problem. I took it out of the circuit and ohmed it. It didn't look bad but I was getting some small "varying" readings instead of a dead short between terminals.
So off I went to the JD dealer and purchased a new PTO switch. My old PTO switch was connected via a PLUG which could only be installed 'correctly'. The new switch had a different pin pattern which didn't fit the plug. I thought I'd be smart and remove each wire from the plug, label a piece duct tape with ink, and wrap it around the wire. It wasn't long until I found out ink on duct tape comes right off when handled. Pretty much all of my markings were indecipherable. I fiddled with it for a while and got it to where it looks like it's working 'somewhat'. When I turn the key on, the battery indicator light comes on 'brightly' and then dims noticeably when I pull the PTO switch out and I can hear the PTO clutch engage. HOWEVER - the engine still doesn't crank!! I talked to the guy at the JD dealer about it yesterday and he thought maybe one of the interlock switches had gone bad. I checked them (Brake and Seat) and they appear to be working. The only other thing I could think of was the "ignition key circuit board", which neither of my local JD dealers had in stock.
Today I drove 180 miles (round trip) to a dealer I was told had one, only to find that my local dealer:00000060: had given me a part# for the wrong/different circuit board. Fortunately the dealer:thThumbsU I went to took the time to do a little looking around, and came up with the right Part# and thankfully had one in stock! I installed the new start key circuit board, jumpered out the seat switch, compressed the brake pedal and turned the Key to START! Nothing Happened:dunno::banghead3!! No cranky!! Now I'm $160 into this thing and haven't impacted the problem at all.
I'm at a loss as to what to do next!!! Here are my thoughts, observations, and questions.
I may still have the PTO switch NOT wired correctly. Can send pictures of the Old (unwired) and the new one (installed) if needed.
Could the PTO clutch have failed in such a manner that the engine would have continued to run but not start after shutting it off?
Are there any other "interlock/safety" switches besides the two I mentioned?
There is a Large heat sink mounted on the frame, with 2 bolts and no components showing, it's behind the plastic shroud that holds the start key and the PTO switch. What's it for and could it be the bad guy?

I've yelled at my grass to stop growing but it's just ignoring me.. Any help would certainly be appreciated!!!!

jdurnya · May 14, 2015

i would just unplug the pto switch as well as the pto.. im fairly certain that shouldn't interfere with the tractor cranking if it is disconnected.... sounds like you addressed most all.. next step would be jumping the solenoid to see if she cranks over..

grenneam · May 14, 2015

jdurnya said:
i would just unplug the pto switch as well as the pto.. im fairly certain that shouldn't interfere with the tractor cranking if it is disconnected.... sounds like you addressed most all.. next step would be jumping the solenoid to see if she cranks over..

I'm going to go do that right now. Thanks for the input - will let you knowthe results.

themoose · May 14, 2015

You said the PTO clutch can be heard engaging, are you sure it is disengaging?
There aren't many things that will stop one from cranking other than the brake, pto, seat, or ignition switch.

Have you checked the battery terminals for corrosion, the lights can still come on, but not enough juice make it to the starter to get it to crank.

Hopefully more of the electrical experts will be along soon.

grenneam · May 14, 2015

jdurnya said:
i would just unplug the pto switch as well as the pto.. im fairly certain that shouldn't interfere with the tractor cranking if it is disconnected.... sounds like you addressed most all.. next step would be jumping the solenoid to see if she cranks over..

I just disconnected the PTO switch - didn't disconnect at the Clutch because I Don't think it's normally energized. However I jumped the 2 big lugs on the solenoid and I just got some sparks but nothing else - didn't hear it click or anything and the starter didn't try to turn. I removed the spark plug and turned the crank from the screen at the top and it seemed OK. I could hear air sucking and pushing.

grenneam · May 14, 2015

themoose said:
You said the PTO clutch can be heard engaging, are you sure it is disengaging?
There aren't many things that will stop one from cranking other than the brake, pto, seat, or ignition switch.

Have you checked the battery terminals for corrosion, the lights can still come on, but not enough juice make it to the starter to get it to crank.

Hopefully more of the electrical experts will be along soon.

Battery terminals look good. The battery is old but up until 2 days ago this thing has been cranking good for the last couple of years. Plus it's been able to energize the PTO clutch about a dozen times now. I'll put a meter on it and see what it's reading. I'd love to see it be something as simple as the battery - but then I'd have to shoot myself for spending all that money at the JD dealer.....:14_6_5:

themoose · May 14, 2015

just take the positive cable loose and clean it up real good where the wire goes into the clamp and take a wire brush to the wires too, I had that happen to my 265 and it would light up and everything, but wouldn't crank.

If it's not that, it has to be the pto switch, are you sure it is wired up right, you need to find a diagram, or get the right switch.

My LX172 is at my Granddads or I would snap a pic for you of how it is supposed to be.

grenneam · May 14, 2015

Actually one of the first things I did was check the battery cables. The Positive cable seemed a little loose when I moved it - so of course i wiggled it. It snapped off at the battery terminal. Had a heck of a time getting the "remains" off of the cable. Bought a new connector and put it on. Crimped it with a handheld crimper - didn't like the way it looked so I put the crimping tool around the connector and put the whole thing in a vise. It's crimped GOOOD now! Checked the result with an ohm meter --> .1 (point 1) ohms end to end..

grenneam · May 14, 2015

I've sort of got the thing half disassembled right now. So I think I'll put it together in the morning back it out (Push) into the Driveway and jumper the battery to my car. The try the Solenoid test again.

Do you know whether there is any problems associated with jumpering those little batteries to an auto battery????

grenneam · May 14, 2015

I need to apologize to you guys because I've ended up with 2 posts in this forum. I made an original post in another JD forum - discovered that it was the wrong (so I thought) forum and made the same post in this forum with the intention of deleting the original post. However when I went back to delete the original post it said it had been moved to this forum. I don't know whether it moved automatically because of the 2nd post I made or whether the moderator of the original post's forum moved it before I got back.
No matter the case --- I'm sorry for the duplicate!!!

littletractorguy · May 14, 2015

No biggie, us mods can take care of the duplicates... You just focus on getting that machine going! Good luck! :Welcome1:

grenneam · May 14, 2015

themoose said:
just take the positive cable loose and clean it up real good where the wire goes into the clamp and take a wire brush to the wires too, I had that happen to my 265 and it would light up and everything, but wouldn't crank.

If it's not that, it has to be the pto switch, are you sure it is wired up right, you need to find a diagram, or get the right switch.

My LX172 is at my Granddads or I would snap a pic for you of how it is supposed to be.

I just put a meter on the battery. 12.5 volts in the off position. 8.6 volts in the ON (but NOT START position):dunno:. I don't know whether that's good or bad but it seems awfully Low to me. The only thing showing power was the battery light, but I expect the interlocks and the relay on the start key circuit board got some juice too . Do you have any knowledge/expertise as to what the voltage "should be" under that condition??

themoose · May 14, 2015

I don't know what it should read, I just know if the battery is weak and/or not making good contact with the cables, the starter will not crank.

It takes a lot more amps to turn the starter, than it does to light the bulbs or engage switches. I never believed it til I saw it myself, now my first reaction to any "no crank" condition is battery/cables, then safety switches, then fuses, then solenoid, ignition switch, etc.

grenneam · May 14, 2015

themoose said:
I don't know what it should read, I just know if the battery is weak and/or not making good contact with the cables, the starter will not crank.

It takes a lot more amps to turn the starter, than it does to light the bulbs or engage switches. I never believed it til I saw it myself, now my first reaction to any "no crank" condition is battery/cables, then safety switches, then fuses, then solenoid, ignition switch, etc.

Took my battery to a battery store this morning and they pronounced it just this side of dead. Bought a new battery, brought it home, and put it in. I put a screwdriver across the solenoid terminals and the starter tried to crank the engine. Put some of the stuff I've taken apart back together thinking things are looking up! Not so! Turning the key still results in NO Cranking. Rechecked the seat and the brake switch to insure they were shorted as they should be and they were. Pulled the starter solenoid activation cable and stuck a meter in it while turning the key to "start" and got essentially nothing on the meter .4 volts max. I feel like I'm missing an interlock switch somewhere and there is still the possibility I've got the PTO switch wired wrong!! I also feel like I'm rebuilding this thing from the ground up and my wallet can't take much more of that... Looking for a good wiring diagram to see if that will show me anything.. Your information on the battery was dead on - Thanks... If you think of anything else I can try please let me know - I'm still slaving away at it..

littletractorguy · May 14, 2015

Okay, so… Here's my experience with a JD 125 that belongs to a friend of mine when he had a similar problem last summer (not sure where it falls in the scheme of things compared to the LX176, but its a lawn tractor for sure). Long and the short of it, similar symptoms, no cranky… I did the whole enchilada, all the way to replacing the ignition switch. Still nothing. Then I pulled off, cleaned and reconnected EVERY connection I could find (grasping at straws)… One at a time, of course, I didn't totally take apart his system, clean them all, then put them back together. Pulled one, cleaned it, reconnected, tried, rinse, lather, repeat… Til finally it started. It must've worked for him for the rest of the summer, because I got no more calls from him.

Probably not the news you want, but its probably the next logical step.

grenneam · May 14, 2015

littletractorguy said:
Okay, so… Here's my experience with a JD 125 that belongs to a friend of mine when he had a similar problem last summer (not sure where it falls in the scheme of things compared to the LX176, but its a lawn tractor for sure). Long and the short of it, similar symptoms, no cranky… I did the whole enchilada, all the way to replacing the ignition switch. Still nothing. Then I pulled off, cleaned and reconnected EVERY connection I could find (grasping at straws)… One at a time, of course, I didn't totally take apart his system, clean them all, then put them back together. Pulled one, cleaned it, reconnected, tried, rinse, lather, repeat… Til finally it started. It must've worked for him for the rest of the summer, because I got no more calls from him.

Probably not the news you want, but its probably the next logical step.

Thanks for the input - BUT I got it running.. SUCCESS!!! I found a decent wiring diagram on the internet. Took a good look at it and found I did have the PTO switch boogered up. Switched the wires to what was shown on the schematic and VIOLA!! She cranks.

It took me a couple of hours to reassemble all the junk (skins etc.) I removed in the process and permanently install the PTO switch and new start key board ( I've got the feeling the old one is still good). I'll post a picture of it in case anyone wants/needs to try it (could save them $110).

I do have one (1) remaining problem though. In removing the plastic shroud that the PTO and Start key reside on, I also removed the Parking brake lever - you know the little Red Handle that keeps the brake engaged. So far I haven't been able to get that sucker remounted and was wondering if there is a "special way" to re-install it. I've been trying Brute Force but had to back off for fear of breaking the plastic.

Once again I want to give TheMoose a big "THANK YOU" for all of his help and I think his picking on the battery was probably the actual bad guy - although the symptoms made me think it was something else.:dancingpa

littletractorguy · May 15, 2015

Congratulations! Good to hear!

themoose · May 15, 2015

Glad you got her running.

I don't know how the parking brake goes, try looking up pictures of it on JD parts or using google, or start a new thread requesting pics of it.

Not sure if you know this or not but used 48" decks are plentiful for those mowers if you ever wanted to try one. There is one for sale on my local CL for $150 right now.
I got one for my LX172 a few years ago and it really cuts down on the mowing time, you just have to use a different belt from the PTO pulley to the deck.

LX176 Not Cranking - Need help!!

grenneam

jdurnya

grenneam

themoose

grenneam

grenneam

themoose

grenneam

grenneam

grenneam

littletractorguy

grenneam

themoose

grenneam

littletractorguy

grenneam

littletractorguy

themoose

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