Hello. I have an L48 and every once in awhile when I turn the key the engine tries to start right away. Normal operation is turn to the first stop on the key switch to warm the glow plugs, when the glow plug indicator light goes out then I turn the key to the next stop and the tractor will start. But sometimes it just tries to start and it won't because the plugs haven't warmed up. It just tries to turn over. I think it has to do with the foward/reverse pedal because if I press on the pedal while the key is turned it stops trying to turn over. But that's just a guess. Does anyone know what might cause this? Thank you.
L48 ignition bypassing glow plug
- Thread starter ejayb9
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fried1765
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I don't use my L48 in the 6 coldest months of the year, so have never even needed the glow plugs.
It starts easily without any glow plug assistance.
I don't know if my glow plugs actually work!
RickB
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Sounds more like a faulty key switch. The neutral safety switch on the hydro pedal linkage is doing its job just fine.
rbargeron
Elite Member
Are you saying that your starter turns when the key is only in the first position?
The L48 glow plug system has a controller & relay. With key ON, glow plugs run for the right time, based on temperature. Key at START runs the starter. My glow light was only brief & would come back on when running. Glow relay was not clicking in. A new controller 16415-65662 straightened mine out.
The L48 glow plug system has a controller & relay. With key ON, glow plugs run for the right time, based on temperature. Key at START runs the starter. My glow light was only brief & would come back on when running. Glow relay was not clicking in. A new controller 16415-65662 straightened mine out.
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Thank you everyone for responding. The problem went away overnight. But today when I went back to start, same thing happened.
@RickB I have a brand new, fresh out of the bag, OEM switch, I bought just because I thought the same thing. A key problem. I plugged in the new switch and it didn't fix it. Same behavior.
@rbargeron Yes. The starter is turning in the very first position. Normal behavior in the first position is for the glow light on the dash to light up for about half a second. Then after the dash light goes out, I turn the key to the second position and the tractor starts up. But it's skipping the glow plug in the first position and the starter just chugs away. Doesn't start. Nothing happens if I turn the key to the second position. No change from the starter. It just keeps on trying to turn over but won't do it.
There's a small solenoid looking thing under the tractor that retracts when I push on the pedal. It's got a wiring harness coming on the back of it. I was thinking of changing that to see if there is any affect.
@RickB I have a brand new, fresh out of the bag, OEM switch, I bought just because I thought the same thing. A key problem. I plugged in the new switch and it didn't fix it. Same behavior.
@rbargeron Yes. The starter is turning in the very first position. Normal behavior in the first position is for the glow light on the dash to light up for about half a second. Then after the dash light goes out, I turn the key to the second position and the tractor starts up. But it's skipping the glow plug in the first position and the starter just chugs away. Doesn't start. Nothing happens if I turn the key to the second position. No change from the starter. It just keeps on trying to turn over but won't do it.
There's a small solenoid looking thing under the tractor that retracts when I push on the pedal. It's got a wiring harness coming on the back of it. I was thinking of changing that to see if there is any affect.
rbargeron
Elite Member
Attached are pages from the L48 WSM with the start system wiring diagram and its functions.
The symptoms point to the glow relay and/or the controller. The controller is known to fail so I'd look there first. See post #4 for a link to new ones - several under $40. Please post back on what cures your rig. Dick B
The symptoms point to the glow relay and/or the controller. The controller is known to fail so I'd look there first. See post #4 for a link to new ones - several under $40. Please post back on what cures your rig. Dick B
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Thanks, somehow I missed post #4 when I had originally read the replies. I did order a controller off Amazon, and got that yesterday. Plugged it in and no change. I ordered a new glow plug relay this morning- FedEx ground shipping so might not see that until Friday.
I'll update once I get the part in, if that fixes the problem. Thank again!
FedEx delivered the new parts today.
16415-65600 (RELAY, GLOW PLUG)
37150-32240 (SWITCH, SAFETY)
35800-75070 (RELAY, STARTER)
16415-65662 (Controller) was changed on Wednesday. And I already changed the ignition switch.
STILL the same problem. The engine tries to turn over at the first position of the ignition switch. I took the battery out, cleaned the terminals and put it on a slow trickle charge for overnight. I'm headed to Tractor Supply tomorrow to get new terminal connectors and covers. Not that this has anything to do with it, but it will be good to cross it off the list. I'll also check all the fuses tomorrow.
Turn key first position, no glow plug light and tractor tries to turn over but never does. Only thing I can think of next is to change the glow plug.
16415-65600 (RELAY, GLOW PLUG)
37150-32240 (SWITCH, SAFETY)
35800-75070 (RELAY, STARTER)
16415-65662 (Controller) was changed on Wednesday. And I already changed the ignition switch.
STILL the same problem. The engine tries to turn over at the first position of the ignition switch. I took the battery out, cleaned the terminals and put it on a slow trickle charge for overnight. I'm headed to Tractor Supply tomorrow to get new terminal connectors and covers. Not that this has anything to do with it, but it will be good to cross it off the list. I'll also check all the fuses tomorrow.
Turn key first position, no glow plug light and tractor tries to turn over but never does. Only thing I can think of next is to change the glow plug.
RickB
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Keep throwing parts at it, something will cure it sooner or later.
rbargeron
Elite Member
The problem comes and goes, right? They're the toughest to isolate. The starting circuit is sometimes getting an unintended ground somewhere in the wiring. A long shot is corrosion or shorting wires inside the solenoid on the starter.
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rbargeron
Elite Member
Maybe try bypassing the built-in glow control system. Put one jumper cable on the battery + terminal, and carefully touch the other end to any one glow plug for a few seconds (they'll all run). Then turn the key....
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Yes, problem comes and goes, but this has been the worst stretch. Normally if I let it sit overnight it will work the next day, but it's been down for a week now.
I just went out and tried to start it. Key in first position was normal behavior. Glow plug light on dash lights up and then goes out. I turned key to next position to start engine, and it just tries to turn over but doesn't. I turned the key all the way off. Waited for about 20 seconds and turned key to first position and it tried to turn over right away. So the very first time I turned the key it was normal but the second time I tried to start it, the first position was messed up.
Battery is fully charged, I cleaned the terminals, and put in new connectors. All the relays in the dash are replaced. Tank is full and I added some treatment to it, just in case. I just got finished ordering new glow plugs, will take 5-7 to get those in.
I changed the starter, 2 summers ago. Hopefully that's not it. Will definitely be the last thing I replace.
I'm going to try this tomorrow.
I saw a couple of YouTube videos on how to check for resistance on the plugs. I'll try that too.
rbargeron
Elite Member
I've noticed you've described it a few times as.. "and it just tries to turn over but doesn't." Does this mean the starter turns the engine but it doesn't fire and run? Or does it mean the starter only clicks?
Sorry for the late response. I've been busy rewiring the entire thing. It's so incredibly irritating. I change something and think it's going to be fixed and still nothing. I'm getting ready to call the dealer and have them come out.
Anyway, to answer your question...the starter turns the engine but it doesn't fire and run. The engine is chugging away like normal if the key was in the start position but the key isn't in start its in the run position. So I'm thinking the plugs haven't had a chance to heat up and that's why it won't start. I changed the plugs, the bus bar across the plugs and the little nuts holding everything down. I wanted to eliminate any rust problems. So basically everything is nearly new. I've even changed out some of the wiring.
I did buy a shop manual from Ebay. So I'm trying to replace all wires from key switch to starter. I've changed every relay under the panel. Twice. Still the thing tries to turn over in first key position.
K5lwq
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When it turns over in the first position, what happens when you turn the key to second or start position?
My thought on why it will not start is the fuel cut off solenoid is not energized. That normally takes place when key is in start position.
My thought on why it will not start is the fuel cut off solenoid is not energized. That normally takes place when key is in start position.
rbargeron
Elite Member
Just noticed you're in VA - an L48 should start with no help from the glow system - sounds like fuel isn't flowing when it just cranks
Agree with K5lwq - the stop solenoid (part 190 on attached) has to be powered and working for fuel to flow. Try feeling the stop solenoid while somebody turns the key on-off - should be able to detect the click. (stop solenoid withdraws at key-on)
Agree with K5lwq - the stop solenoid (part 190 on attached) has to be powered and working for fuel to flow. Try feeling the stop solenoid while somebody turns the key on-off - should be able to detect the click. (stop solenoid withdraws at key-on)
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