JD LX188 Won't Start

[Chuck M]

Mower started right up as usual but noticed the tire low on air, so I pulled it into the garage to fill the tire. I shut the mower off, filled the tire and mower would not restart. All I get is a buzzing sound from the ignition switch. Battery is fully charged.
Wondering if it is the starter solenoid, ignition switch or something else. It seems odd that it would start right up and 3 minutes later won't start at all.
Chuck

 

[gsim]

AFter checking fuses, I'd remove and reseat each one. Don't omit wiring harness inline fuses. I had an incident where engine would die when I released the key after starting it. I have a diesel, and turned out that I cleared the trouble by removing and reseating the fuse to the fuel solenoid. Sometimes fuses that have been in service a long time will oxidize inside the frmale part of the fuse socket. In fact, I've had same trouble on wiring harness connector plugs a couple times. One was loose, one was oxidized a bit. Even had an incident on my old Ford f-150 where wiring harness conector at pump was oxidized causing intermittent fuel pump failure. Was down in socket where fuel pump pig tail wires plugged into pump body. New pump would not have fixed it. Cleaning fixed it tho.

 

[Chuck M]

Removed and reset the fuses. Removed and cleaned the battery connections. Checked the connections on the starter solenoid and all looks good. Grounds look good. Still getting a buzzing sound from one of the small gray electronic modules on the back of the ignition/control panel. Mower doesn't click or turn over still.
Other suggestions welcomed.

 

[bertsmobile1]

Sounds like a duff relay.
Most of the relays JD use are std 30A auto relays
See if the "little grey box" pulls out of a socket

 

[gsim]

If you use jumper cable and put positive battery directly on starter terminal., will id crank? If so, try replacing that relay that is buzzing. They are supposed to either make or break congacts inside, but never buzz. Lo volage to a relay can make it buzz. If you have voltmeter, can look to see if you are getting full 12V DC to that relay when starter switch is turned. Also try to get hold of a copy of wiring diagram.s It'll help you run down the trouble.

 

[Chuck M]

Update. Battery has 13.4v, The positive terminal on the solenoid has 12v. The ignition wire at the solenoid has 12v when the key is turned. The solenoid terminal that goes directly to the starter has no voltage even when the key is turned. Took the solenoid off and went to JD store. Gave them all the info and they tested the solenoid and said it was bad. I paid $93 for a new starter solenoid, installed it and still have a lawn mower that wont start and only buzzes on one of the relays when the key is turned. Unfortunately the relay is soldered to the circuit board.
When I put a jumper wire from the positive solenoid terminal to the starter terminal I get a spark but the starter doesn't turn. JD is trying to find a more useful wiring diagram for me. The one the parts rep was using didn't show the circuit board with any detail.

 

[bertsmobile1]

If you post your full model & serial number I will see if I can find the circuit diagram for you.
The electrical section of the service manual over 100 pages long so too big to post here in full
OTOH you could buy the LX manual from JD which tells you where everything is , how to test it and what the results mean.
Well worth every cent

 

[gsim]

Update. Battery has 13.4v, The positive terminal on the solenoid has 12v. The ignition wire at the solenoid has 12v when the key is turned. The solenoid terminal that goes directly to the starter has no voltage even when the key is turned. Took the solenoid off and went to JD store. Gave them all the info and they tested the solenoid and said it was bad. I paid $93 for a new starter solenoid, installed it and still have a lawn mower that wont start and only buzzes on one of the relays when the key is turned. Unfortunately the relay is soldered to the circuit board.
When I put a jumper wire from the positive solenoid terminal to the starter terminal I get a spark but the starter doesn't turn. JD is trying to find a more useful wiring diagram for me. The one the parts rep was using didn't show the circuit board with any detail.

Zowie! $98 for a starter solenoid? I think at this point, I'd just go to NAPA and buy a 30 amp push button switch. Run a 12 ga wire to it from the battery, run another 12 ga wire frm button switch to solenoid. This way, you can just turn ign switch to 'ON' and pubh button to start your mower. I rigged my old International track loader that wey when the 'START' portion of the starter switch died. Been using it for 20 yrs that way.

 

[gsim]

Update. Battery has 13.4v, The positive terminal on the solenoid has 12v. The ignition wire at the solenoid has 12v when the key is turned. The solenoid terminal that goes directly to the starter has no voltage even when the key is turned. Took the solenoid off and went to JD store. Gave them all the info and they tested the solenoid and said it was bad. I paid $93 for a new starter solenoid, installed it and still have a lawn mower that wont start and only buzzes on one of the relays when the key is turned. Unfortunately the relay is soldered to the circuit board.
When I put a jumper wire from the positive solenoid terminal to the starter terminal I get a spark but the starter doesn't turn. JD is trying to find a more useful wiring diagram for me. The one the parts rep was using didn't show the circuit board with any detail.

Being as that relay is soldered to a circuit board, very likely entire assembly might have to be replaced. Doubt seriously JD would allow dealers to replace indiviidual comopnents in a circuit pack assembly. I shudder to think of their price for that thing if they charged $93 for a solenoid.

 

[Hammermechanicman]

The circuit board is fairly simple. It just contains 2 relays a couple relays and some diodes. I would inspect the solder joints for a cracked solder joint. I have seen quite a few JD machines with cracked solder joints from vibration. Especially look at the solder joints of the wire connections. Does it buzz when you turn the key to run or when you turn it start?