753 locking up and stopping

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daytona701

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Nov 26, 2019
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753 with 1100 hours works well except controls and engine lock up and stop about every 12 to 15 minutes. Will start and run normal until it happens again. Not sure if it's in the instrument panel or inside the machine. Any advice will be greatly appreciated.
 

Tazza

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What happens if you press and hold the lights button, do you get any error codes?
When it locks up and shuts down, do the panels stay on?
 
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daytona701

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Nov 26, 2019
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What happens if you press and hold the lights button, do you get any error codes?
When it locks up and shuts down, do the panels stay on?
Tazza, the traction light on the overhead goes out. I'm rolling and the wheels lock up and stalls the engine. Turn key off and restart and work some and it happens again.
 

Mlewis

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Feb 26, 2022
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Not sure if it's the same but look at my previous post it's under 753 c problem and go through all of that but after over a year of trouble shooting it ended up being the BICS controller itself. I have replace it about 2 weeks ago been running great ever since. Hope this helps
 

koko

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Jan 30, 2022
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Sounds like you have an issue with the solenoid that locks the front axle. Tilt the cab, locate & remove the solenoid & mechanism that locks into the front drive axle & see if you still have the same issue. My 863 did that intermittently & I removed, & replaced with a cover so dirt does't get inside. You will have no lock & the machine will roll when on a grade & shut off.
 

bullrake

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Mar 6, 2007
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Had what may be the same problem with my 763-F. System would suddenly lockout which, if moving in forward or reverse, would force a an abrupt stop and lockout all of the hydraulics. In my case root cause was a bad ground connection in the BICS loop. The location of that connection on my machine was to the top of the front shield that is under the seat. You have to lift the cap to get at it.
 

Daveb68

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Oct 17, 2018
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Sounds like you have an issue with the solenoid that locks the front axle. Tilt the cab, locate & remove the solenoid & mechanism that locks into the front drive axle & see if you still have the same issue. My 863 did that intermittently & I removed, & replaced with a cover so dirt does't get inside. You will have no lock & the machine will roll when on a grade & shut off.
I did that to my S250 and even after removing the magnet spring mechanism it somehow still intermittently locked up on me?
How could that be possible? Any suggestions would be great.
Daveb68
 

koko

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I believe the spring will "force" the pin into the slot, so if you still have the pin in there, that needs to be removed.
 

Daveb68

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I believe the spring will "force" the pin into the slot, so if you still have the pin in there, that needs to be removed.
I removed the spring and the magnetic pin and unplugged the solenoid were it goes into the harness and re-installed the cover to keep any debris from getting into that area.
I'm wondering if I needed to do anything with that end of the plug from the wiring harness we're it is supposed to plug into the solenoid.
Now that I think of it, I'm pretty sure that I plugged them back together, because the wiring connector plug from the solenoid is still there even after you remove that magnet and spring mechanism on the top piece that you bolt back onto the machine we're that solenoid was to keep any debris out.
Im not with the machine now but I will look it over when I get back to my shop tomorrow and shoot a few pictures. I will be looking around for any breaks in the wiring harness in that area and check all grounds to be sure they are all good.

Thank you for responding, I definitely appreciate the input.
I will repost when I pin point the problem.
I did replace the solenoid so it has to be a bad ground or wiring issue, that's the only thing that makes sense.
Again Thank You,.
 

Daveb68

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Oct 17, 2018
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32
Not sure if it's the same but look at my previous post it's under 753 c problem and go through all of that but after over a year of trouble shooting it ended up being the BICS controller itself. I have replace it about 2 weeks ago been running great ever since. Hope this helps
Thank you i will test that tomorrow.
 
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daytona701

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Nov 26, 2019
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31
I removed the spring and the magnetic pin and unplugged the solenoid were it goes into the harness and re-installed the cover to keep any debris from getting into that area.
I'm wondering if I needed to do anything with that end of the plug from the wiring harness we're it is supposed to plug into the solenoid.
Now that I think of it, I'm pretty sure that I plugged them back together, because the wiring connector plug from the solenoid is still there even after you remove that magnet and spring mechanism on the top piece that you bolt back onto the machine we're that solenoid was to keep any debris out.
Im not with the machine now but I will look it over when I get back to my shop tomorrow and shoot a few pictures. I will be looking around for any breaks in the wiring harness in that area and check all grounds to be sure they are all good.

Thank you for responding, I definitely appreciate the input.
I will repost when I pin point the problem.
I did replace the solenoid so it has to be a bad ground or wiring issue, that's the only thing that makes sense.
Again Thank You,.
 
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daytona701

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Nov 26, 2019
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Yesterday working machine it locks up in forward or reverse. There are no codes on overhead. The traction control light goes out. What does traction control do and what is BICS? I will tilt cab and check grounds. I've found in the past bad grounds cause a lot of problems. Thanks to everyone for the replies.
 

Daveb68

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Oct 17, 2018
Messages
32
753 with 1100 hours works well except controls and engine lock up and stop about every 12 to 15 minutes. Will start and run normal until it happens again. Not sure if it's in the instrument panel or inside the machine. Any advice will be greatly appreciated.
I read somewhere that if your not getting a constant 12 volts on your battery it could cause your brake system to lock up and that was about how long my S250 was running for before it also locked up the brakes.
if it does happen and you really need to move it right away then throw a quick jump on the battery bringi it up to 12 volts and then figure out we're your draw is coming from. I started by installing positive & negative new Bobcat factory terminals. The negative has two grounds, one to the steel panel underneath the engine right next to the battery & another ground that goes directly to the engine block. The positive goes from the terminal over to your solenoid & then directly to your starter.
i recommend the top post terminals because all of the heavy gauge wiring comes right out of the sealed led terminals and everything is nice and tight like it was from the factory. If yours are good then leave them, maybe just take the bottom ground off & grind any rust or other unwanted debris off and re install then clean up any other crap that looks like it could use a cleaning and make sure all of the bolts & nuts are tightened up good.
The new factory terminals with new wiring isn't cheap so if you can avoid replacing them then do so and spend the money trouble shooting looking around for faulty wiring and give your fuse panel a good look through. I've seen corroded fuses snapped off and stuck in the panel so look for that & then make sure all the right size fuses are in the proper spot then look over your relays, you know all of the obvious stuff and hopefully that will solve your problem. It appears to be one of the more common issues I've seen in this forum. Oh, make sure you check your brake switch & that the red light inside the switch is on when brake is activated & also make sure when the machine is running & you disengage your brake switch that all four round lights on the Bics panel are lit up because depending on what those lights are doing when your brakes lock up can give you some hints as to what the problem could be too. Check all your wires under your seat when you lift up the cab are good especially the ones coming directly out of the back of your fuse panel.
 

Daveb68

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Oct 17, 2018
Messages
32
Yesterday working machine it locks up in forward or reverse. There are no codes on overhead. The traction control light goes out. What does traction control do and what is BICS? I will tilt cab and check grounds. I've found in the past bad grounds cause a lot of problems. Thanks to everyone for the replies.
Traction control is for the brake solenoid & the Bucs is the panel on the left we're the 4 round circle lights light up after you put the seat bar down, disengage your brake switch & when you hit the green press to operate button. Under each circle it explains what each light is for and if one of the lights is not on or blinking with the seat bar down & the brake switch disengaged that's usually a good starting point to what's wrong but as I mentioned before a bad ground can cause a similar problem so troubleshoot before you go out & purchase expensive parts from Bobcat.
 
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daytona701

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Nov 26, 2019
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Hi, have not had a chance yet to work on the machine. May have time this week. Will start at the battery to check voltage and ground/positive connections. Then lift cab to check grounds around front axle/solenoid. If the seat sensor is faulty will that cause the parking solenoid to engage while the machine is being operated?
 
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daytona701

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Nov 26, 2019
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Hi, have not had a chance yet to work on the machine. May have time this week. Will start at the battery to check voltage and ground/positive connections. Then lift cab to check grounds around front axle/solenoid. If the seat sensor is faulty will that cause the parking solenoid to engage while the machine is being operated?
 
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daytona701

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Nov 26, 2019
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Running the machine it would lockup. Turn the key and would start and run then lock up again after a while. The traction lock light would go out when this happened. Then the seat bar light started blinking on/off and the machine would stop but the engine kept running. Figured it was a ground common to both the seat bar sensor and traction lock circuits.
Removed the single bolt that secures ground wire and access cover on left side of cab at shoulder height which is a poor design. Also removed bolt on frame just behind cab on left side at shoulder height that secures another ground wire. Cleaned connections and made a new ground wire cable to connect both grounds and reassembled.
Also removed the 30 amp fuse and relay for the traction lock, cleaned the terminals and doused the electrical panel with WD-40. The machine now works without locking up or stopping.
 

brdgbldr

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Jun 1, 2012
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Great to hear you got it fixed.

Thank you for posting your fix. Many people will find this info useful.
 
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