L3901 safety switches

Timberlake580

New member
Aug 28, 2014
8
1
1
North Carolina
Hi all,
Once again, my L3901 is sitting out on the pasture and won't start. I know it is a safety switch somewhere not allowing the engine to even turn over. This has happened several times before. The first time it was when I was using a PHD and all of a sudden it wouldn't start after hours of flawless operation. After much frustration and internet searching, I found out that the PTO lever cable was kind of sticking and not triggering the little switch when it was disengaged. By simply pulling the handle back to trip the switch, wall-la! Fired right up. Fast forward a few months and again, for no apparent reason it would not start again. This time, I think it was the seat sensor not being pressed down enough. Now today, I was hauling firewood back and forth for several hours with no problems. I get off the tractor for awhile and go to move it again and...nothing. It's the same symptoms as before. Turn the key to the first stop and the pump starts, dash lights come on, etc. Go to start it and it doesn't even try to turn over. I know it's another d@***n safety switch somewhere not allowing it to start. I've checked fuses, tried rocking the treddle peddle back and forth, checked the PTO lever (wasn't even using it) and can't find the culprit. Does anyone have a comprehensive list of all the safety switches on this machine that could cause this so I can systematically go and check them all? I've already taken care of the seat sensor thing by physically tying the lever down so it's always "safe". I'm all for safety features, but this is getting rediculous! I've checked all the ones I know of, was hoping someone knew of others I could go out and check. Thanks a lot.
 

cn2redjeep

New member

Equipment
L3901, tiller, finish mower, pallet forks, rear blade
Mar 27, 2015
25
0
0
Illinois
I have been thru those safety switch problems myself.
The only thing that might be causing this:
If HST pedal isn't in exact neutral position
Or if that Bu:: S::t regeneration cycle isn't completed.


Sent from my iPhone using Tapatalk
 

Timberlake580

New member
Aug 28, 2014
8
1
1
North Carolina
Well, wouldn't you know it. I go out to double check the fuses and battery connection (even though i know that's not it cause the dash lights and pump comes on). Pulled the two fuses by the battery, they're both fine. Wiggled the battery connections, they didn't even budge. No corrosion. Tractor has 135 hours on it. Anyway, go to turn the key again and it fired right up!!! No idea what I did. I guess one of those fuses could have been loose, but as hard as they are to pull out, I would doubt it. Or maybe it just wanted me to look under the hood agian :). Anyway, I'd still like to know if anyone knows of other safety switches that can cause problems. I'd like to bypass them if possible. Or at least know where to look next time I'm stuck out in the woods and the tractor won't start!
And yes, redjeep, the regen thing is completely nonsensical to me. I sit there with the engine reved up to 3000 or whatever for 15 minutes the whole time burning more fuel than I would be by running my PHD or simple firewood stuff. I like how they say "no problem, just keep working while it does the regen". Well, try digging post hole at 3000rpm! No, I sit there and smell my $3.00 diesel burn away... ain't the EPA a bunch of smarties!??
 
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Timberlake580

New member
Aug 28, 2014
8
1
1
North Carolina
Also, on the HST peddle thing; where is the switch or sensor that knows when it's in neutral or not? I've looked under there and don't see anything that looks like a safety switch. That's the first thing I try now when it won't turn over, but I guess I've never tried to start it with the peddle pushed down in either direction. Maybe it's internal?
 

NS kubota

New member

Equipment
Kubota MX4800, Norse 350 logging winch, Hla 2042 pallet forks, Woods BSS60
Dec 21, 2014
62
1
0
Nova Scotia, Canada
Timber lake 580, we had the same tractor until trading this Aug for a Mx4800 and the only switch that gave us trouble was the seat safety switch when I lifted slightly off the seat which wearing the seatbelt cured. When you said the tractor would not start butafter sitting for a bit it started right up I am wondering if the hat peddle was not in the neutral position at the time and maybe sprung back into neutral over time ie. ( 1/2 hour to an hour). Like I said we had no trouble like this with our. L3901 however the machine was abit light for the work we do.
 

LMTractorGuy

Member

Equipment
L2501HST, LA525, RCR1260, BB1260, Titan 48" SS Forks, Stump Bucket
Sep 20, 2016
70
1
8
SC
Timberlake, I feel your pain. I have a similar post. Search "L2501 would not start today". I has only happened once to me at around 20 hours. I hope you can figure it out. Is PHD, post hole digger?
 

LMTractorGuy

Member

Equipment
L2501HST, LA525, RCR1260, BB1260, Titan 48" SS Forks, Stump Bucket
Sep 20, 2016
70
1
8
SC
Chim, thanks for the link. Does anyone have pictures of the HST safety switch and how to adjust it. Is it the same on all "L" model HST tractors?
 

lugbolt

Well-known member

Equipment
ZG127S-54
Oct 15, 2015
5,205
1,889
113
Mid, South, USA
I was going to offer you where and what each switch does, but when the word bypass got thrown out there, I'm out. You're on your own with that.

There's a way to test each switch on the L01 series without doing anything but pushing a button. You can figure it out by use of a WSM.
 

Takota

New member

Equipment
L3301
Jan 27, 2016
22
0
1
Sanford, Fl
I can start my L3301 standing next to it. I don't need to be on the seat. The seat switch does work if I try to press a pedal while off the seat, or if I stand to see where the forks are pointing out front. So, I don't believe the seat switch should affect it.
 

Timberlake580

New member
Aug 28, 2014
8
1
1
North Carolina
I was going to offer you where and what each switch does, but when the word bypass got thrown out there, I'm out. You're on your own with that.

There's a way to test each switch on the L01 series without doing anything but pushing a button. You can figure it out by use of a WSM.

Well, ok. Maybe bypass them is not my intention, but I would like to know where to check next time I go to turn the key and nothing happens. Especially when I'm out somewhere where I couldn't get a trailer or tow truck to it even if I had to! I do understand the reason for safety switches, but when they malfunction rendering my $25k machine utterly useless, I do get frustrated! PTO switch? Get it. I'm glad it's there and glad I know how to fix that one. I think this time it actually was the peddle position because it happened again after my second post. THis time I touched the peddle one way and it fired up. Seems like it's been something different every time. And yes, I did "bypass" the seat switch because digging post holes by myself, I find the need to move the tractor forward or backward an inch or two and to judge things more easilly, I need to be beside the tractor and push the peddle with my hand. But then I get back into a normal riding position to run the post hole digger. But thank you all for your input.
 

chim

Well-known member

Equipment
L4240HSTC with FEL, Ford 1210
Jan 19, 2013
2,111
1,225
113
Near Lancaster, PA, USA
Chim, thanks for the link. Does anyone have pictures of the HST safety switch and how to adjust it. Is it the same on all "L" model HST tractors?
Sorry it took so long to get back with pics. Our Thanksgiving will be tomorrow so all the kids can make it so I had a little breathing space today.

Here are two shots of my L3200's HST switch. Maybe yours is similar. The switch on mine is located in the center area below the dash. One picture will give you an idea of the location and the other shows the plunger that is actuated by a tab on the HST pedal and the locknuts. After making the adjustment last November I haven't had any trouble. Hope this helps.
 

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LMTractorGuy

Member

Equipment
L2501HST, LA525, RCR1260, BB1260, Titan 48" SS Forks, Stump Bucket
Sep 20, 2016
70
1
8
SC
Chim, I looked today and my L2501 seems to have the same switch under the dash. I have not adjusted it yet. Today several times when getting off the seat the tractor was cutting off. I moved the HST pedal to try to get it centered and I was able to get off the tractor and it stayed running. Would the HST switch adjustment be causing that as well. Thanks for the great pictures.
 

chim

Well-known member

Equipment
L4240HSTC with FEL, Ford 1210
Jan 19, 2013
2,111
1,225
113
Near Lancaster, PA, USA
I'd blame the switch as the cause. If the switch thinks the pedal isn't in a neutral position, it will want to shut down the tractor if the seat is unoccupied. It's been a while since I adjusted the switch on my L3200 but if I recall, it was easier if the wires were unplugged and the bracket was unbolted. You're on the right path.
 

LOGODUBYA

New member
Jun 19, 2017
1
0
0
murray,ky, usa
there is a wire that fits into a slot on your starter which is on the left hand side of your tractor pull that wire out and plug it back in just had to do this myself on mine now it starts no problem don't even have to be sitting on it
 

JG1358

New member

Equipment
Kubota L 3901 HST
Nov 8, 2022
2
0
1
Stahlstown PA
Also, on the HST peddle thing; where is the switch or sensor that knows when it's in neutral or not? I've looked under there and don't see anything that looks like a safety switch. That's the first thing I try now when it won't turn over, but I guess I've never tried to start it with the peddle pushed down in either direction. Maybe it's internal?
it is directly behind the plate that protects the brake lock lever. 3 10mm bolts and you can't miss it. Not sure what the function is exactly but have a question into JUST ANSWER mechanic and waiting to hear back!