Anyone Replace an LS starter switch?

[alexpops]

Like the title says ... wondering what the common symptoms were, if any. Mine as follows:

Was doing grapple work without any problems, then noticed the hydraulics getting wonky (sticky/jerky movement, not smooth like usual), so I head towards the shed figuring I may need to top off Hydraulic fluid, though that seems strange, since it was fine a week earlier, & no transmission issues or noises. When I drove her closer to shed & put in neutral and idling, I also noticed a belt squeal, so figured that the alternator needed tightening as well ... yup. Hydraulics were fine, at levels of a week ago. Tightened the alternator belt & went to restart, nothing. OK, I figure, the battery was getting undercharged due to slipping belt (even though I never saw a dip in volts while running), battery reads right at 12V so since it was late, starting to rain & I was hungry, threw on the charger & let it go through its cycle overnight. Next morning, charger shows battery is fully charged, & after disconnecting charger, voltmeter shows 12.75 and load test comes out fine. Go to start ... nothing & the dash won't light up. OK, maybe I blew a fuse when I tried to start with a low battery & the amp draw got too high for one of the fuses. Nope, all fuses lit the test lamp on both legs. Grounds are clean & cables were replaced after Hurricane Ian along with the starter, so the cables & starter are good.

Go through a few rounds of trying to start, pulling/reinserting the key, jiggling the lock mechanism, & finally see lights in the dash. When I try to start again, starter clicks once & dash dies again. Open the panel & start checking the fuses again with multimeter this time & notice low volts (5V) on all fuses both legs. Recheck battery & it's 12.7 & load test comes up good again. So, take off other panel, remove the key switch & start testing the connections there ... getting 12.67V at the B+ position, then see 5V on both the ACC & Solenoid positions, but no heat detectable. I find it hard to believe anything inside the switch could be eating 7 volts with resistance & not generate heat that I could feel? I ordered a new key switch & will see if that fixes the problem when it gets here in the next 4-5 days.

Am I missing something? There isn't any thermal overload protection in the circuit that I could find (other than the Main fuses & the ones at the panel), but I will admit that I have always hated tracking down electrical gremlins. Is there something in the switch to protect the ECU that might drop key voltage (out) to 5 volts as a protection measure or is it like any normal key switch (12 in/12 out)?

 

[GS650GL]

There is nothing in the key switch to reduce voltage. 12 in, 12 out. I had the same problem when I would try to start, the dash lit up but starter clicked once and the dash lights all went out and lost all power. Cleaned battery terminals and found a loose connection where small wires connect to positive battery cable clamp. Also had to clean the connection where the negative battery cable grounded to the tractor frame. It was rusty and made intermittent ground connection. It would power the dash OK until extra load on the circuit when trying to crank the engine. Starter clicked once and lost all power. Also showed low voltage of 3 to 5 volts at fuses after that. Some models have a main fuse up by the + battery clamp and also in a small plastic box above the starter. The ones above the starter are Buss type fuses that have prongs that are connected to studs with nuts. The prongs can corrode and the nuts are sometimes loose. These fuses feed the fuse box under the dash which would explain low voltage there. The low voltage at your fuses is upstream from the key switch so the switch is not likely to be the problem although it's not impossible to have a bad switch. A few people have had to replace a key switch but the probability is low. Negative ground cable connection to frame and Buss fuses above starter are most likely. There are also ground connections on firewall behind engine on right side. You may get a S1485 F11 fault code because of low voltage to the dash. It might not go away when the problem is fixed. It sometimes takes awhile and after putting several hours on the tractor it will eventually go away. Good luck.

 

[Avenger]

You could bypass the switch with jumpers. See if that solves your problem. If not, then it's not your switch. They hydraulic issue is not related to this. Not sure if you were trying to solve for both?

I know you stated your checked the ground, but I would look at that again. Take the ground cable off the frame, clean it all very well, maybe sand any paint off the frame, and reinstall tight.

I have had this exact same problem. And after an hour or so of diagnosing, it was the connection. My friends tractor was the same problem too. Thought his battery was dead after it appeared it wouldn't take a charge. He didn't have a load tester, only a multimeter and it was showing over 12v. He assumed, due to lack of power or minimal clicking at the starter, that the battery was dead. Replaced it, and had the same issue. Thats when he called me. Took me 5 minutes to take the ground off, clean it, and replace it. Tractor was up and running.

That ground is the fault of many electrical problems on these tractors. Thats the first thing that gets checked these days.

 

[Mtnmnstr]

I had a switch issue. I could only crank it so the 3 cyl would cycle one time and stop. then I had to reset and do it again. maybe 5-6 time before it would start. I thought it was a new safety thing, kinda. When I took it in for a major recall I asked about it. The switch was not carrying all the amperage to start. Once it got hot the contact separated and stopped transferring power.