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I have an early John Deere gt262, ser # 015314 that was running fine. I turned off the switch and when I went to restart it wont do anything. I have voltage on all three solenoid posts when the key is turned on and it increases when turned to start but nothing happens. I switched solenoid out with another working solenoid and same results. I can only find 2 safety switches, transmission and seat, and have jumped both of those. When i turn on ignition the dash lights come on dim. I disconnected the PTO switch and the dash lights get brighter, not sure why. Also both fuses are good. I'm stumped, thinking it is possibly Pto switch or ignition switch. Any ideas would be appreciated

What is the battery voltage with the key off, with the key on, and when in the start position.

Voltage ?

Increases ?

You should have battery voltage > 12 .5 v at one cable end, nothing any where else till you turn the key when you should get battery voltage at the spade terminal which closes the solenoid to give you battery voltage at the starter cable and cause the starter to crank.

If you have 12.5 at te starter cable & the starter is not ranking the engine then either the mounting bolts are loose so you are not getting a good ground connection or the starter is toast.
Not a young machine so time for new brushes in the starter at least.

voltage of battery is 12.47. I removed the starter and had it tested, it worked perfectly. battery connections are tight. The dash lights with the PTO switch connected are dim and get brighter when disconnected.

Battery voltage at rest 12.5
Battery Voltage with key on 12.5
Battery voltage in start position 12.5
Voltage at solenoid on lead and starter side is 8.5 volts with key on and 11.9 with key turned to start position

But no click and nothing happens

Sounds like the solenoid is deceased.

I actually replaced the solenoid and it did same thing, then i removed the starter and solenoid and took it to a rebuilder to have it tested. It worked perfectly. It has a kawasaki engine and the solenoid is mounted to the starter.

Without a wiring diagram to look at it is going to be hard to troubleshoot..But the solenoid trigger terminal should have no voltage on it except in the start position. Don't know if JD is using a remote starter relay or not without the diagram.

I thought so also, that is why I was thinking it was the ignition switch or PTO switch

Well since no one else willing to download the SM, I did.

Starting circuit consists of the PTO switch (off), neutral safety switch (engaged by the brake pedal being depressed), and the ignition switch (in start position)

If my understanding of the schematic is correct you appear to have a bad ground on connector X4 pin 4 of the A2 Interlock Module (circuit board with the relays and fuses). This would explain why there is a voltage on the PUR/WHT wire at the starter solenoid in run position of the ignition switch.

Here is a question. Where are you testing the voltage ground wise? At the battery or the engine? As it can be a bad frame ground point. Loose engine bolts or badly corroded battery cable are a couple examples.

Also the A2 interlock Module comes in two versions. operational the same. Early version had two separate relays and the later has a single dual relay.

I was using battery ground for testing

Just checked solenoid again using engine as ground and no voltage on spade terminal or starter post. Since the issue is in circuit board, which is connected to ignition switch, can it be repaired or am i looking at a new switch/board? Mine is the older board with a single relay.

I grounded battery to frame with jumper cable to ensure a good ground and tested solenoid. Now with key in start position, spade terminal on solenoid is 6.52 volts and nothing on starter terminal. Tried jumping battery (grabing at straws) and no change. I am going to check ground points.

Okay with the other lead of the jumper cable set go from battery positive to main post of the starter (ie the large cabled one) and then try. It is looking you have bad connections but finding them can be a challenge for the inexperienced. It is even for me and I have been doing it for over 40 yrs.

I had a few that all the voltages were there until the connections got loaded then they would drop out. It took me nearly 4 hrs to run it down.

As will see from the following the main post of the starter should have 12vdc all the time and the solenoid is the one switched.

Partial GT262 wiring diagram.

Just got off JD Parts. They only the switch as part of the module PN AM136679 which is nearly $200.

Now it gets crazy! Cleaned up some terminals and changed out battery for kicks and it started up an ran great. Turned it off and tried again and back to no start and 6.5 volts going to spade terminal on solenoid. Happened twice now and goes back to low voltage on spade terminal. Do you think its a bad ground somewhere or in the switch? I saw the price on the switch and it isnt cheap, want to make sure thats it before i drop 200.00

tried the jumper cable from battery to solenoid and no change

i have a working lx188, i wonder if it uses same switch? i could swap it out to make sure thats the issue

Look at the wiring diagram.
The S terminal on the starter gets is power via the key switch from terminal S2 on the key switch ( they are generally numbered )
S2 is powered from S1
S1 is powered from the brake switch
The brake switch gets it's power from the PTO switch and the PTO switch gets it's power from the Key switch via the fuse.
The most likely cause is a wire that is broken just at the terminal.
I trouble shoot by bypassing each of the switches, one at a time by pulling the plug and jumping across the plug with short wires fitted with a spade at each end.
It is a slow process but eventually the culprit will reveal itself

On the LX188 JD has a different PN so I tend to say it setup differently. Plus I have only the LX186 wiring diagram on hand but on it the switch assembly appear to be same except for missing diode.

But it does sounds like you are more likely chasing a bad connection problem. You going need to start tracing for a voltage drop between wiring points as it sound like you a have a connector that has a high internal resistance and when you was cleaning the connection it made a monetary contact allowing you to start the engine, This one of those hard to find gremlins that causes us techs to spend a lot time hunting down the culprit.

But either way are making a little progress forward just that it painfully hair pulling slow. I have been there before a lot times.

Now for some reason when it sits a while it will start, but if you turn it off it will not start again unless you wait several hours. Then it starts again, but only once, then you have to wait again. Also the Lx188 switch is different

I will try, but the wiring diagrams look like greek to me

I tested voltage on ignition switch, s1 had 13V and when turned to start S2 only had 6.5v. I assume that means a bad contact inside the switch?

Probably not, because s1 voltage drops to 6.5 also when in start mode

Found it!!!! One of the leads on the neutral switch plug. I had it jumped for testing but checking it for a voltage drop i noticed it was getting very warm. Twisted the wire and now starts everytime. Thank you for all your help. I would have just thrown parts at it not knowing it was a bad connection. I kept thinking it was a bad ignition switch, which would have been a $200.00 mistake

Glad you found it. Now you can see how a single bad connection really cause the DYIer to buy a lot of unnecessary parts replacing perfectly good ones and still have the same problem. NOw when you get a chance repair that twisted wire connection properly or you will have the same problem again later.

Check all of your ground wires & connections by hand making sure they are tight & secure & free from rust & corrosion.

Took the plug apart, cleaned it, re-crimped wires and applied dilectric grease. I have test started it over a dozen times and no issues. Weird that this particular mower has positive voltage to all the kill switches most i have dealt with in the past were grounding switches. Thanks again for pointing me in the right direction and saving a couple bucks.

JD, Toro, and a few others use positive safety lines to control relays. Murray, most MTD, and AYPs (Husqvarna) uses grounding circuits. Now some systems (this includes JD) actually use both. This is why wiring diagrams are important when troubleshooting problems.

Only if you know what you are looking at! I cant make much sense out of them

gwbrehm said:

Only if you know what you are looking at! I cant make much sense out of them

Click to expand...

Pinch the kids coloured pencils
Start at the starter motor then trace back colouring the wire.
Unless there is a solid dot or circle where wires cross, they are not connected.
Once you have finished highlighting the circuit you are working on you can then ignore everything else
Not too dissimilar to those maze games they print on the side of cereal packs for the kids

Great buy at this price, JD Technical Manuals are usually over $100, troubleshoot using manual & save.