Bobcat 763 trouble

[Bobcatdaddy]

Got a 01 763G 2200 hrs I bought couple weeks ago I've ran it probably 9hrs started and shut it off a dozen or more times since I've got it. Went to get the machine from a little job I was doing the other day, turned the key over to start and nothing instrument panel wouldn't light up no beep nothing it was like it didn't have a battery on it. So I get out look at battery cable connections try again still nothing. After that i tried a new battery I had just to be certain it wasn't the battery, still no luck. So I get my test light and multimeter start checking fuses and stuff. Big fuse above battery is good, fuses in fuse block were good with test light, switched relays to check them still no luck. Not 100% sure on what wires to check on ignition panel, I borrow a friends ignition panel off another bobcat and mine still won't do anything. Not sure what wires do what so not sure exactly which ones to trace, I do know I've got 12volts on a red/white wire at ignition panel but doesn't seem like it's sending 12 volts out to light up instrument cluster, power to fuel shut off solenoid or anything else. I can hit the light button and it turns on and hour meter lights up but when I hold to get codes it doesn't do anything. Almost like computer is not talking to something but I'm not sure how all that works. I looked grounds over and all look good with the eye. Not sure if it's any correlation but after running the machine for first hour or 2 at random seat bar light would go off along with traction, lift tilt and then come back on and be fine for 5 or 10 min. So I checked a few things out after that and seen + battery cable was loose so I tightened and didn't have that problem again worked awesome rest of the time I used it. Got done turned it off and 2 or 3 days later when I went to get it I have the problem I have now. I know there's several guys on here with a wealth of knowledge on these machines and I'm just looking for other things to check. All input is appreciated. I'll list below what I've checked because I'm sure after this long post be hard to remember what I've even typed.

Problem-763G bobcat nothing happens when key is turned, like it doesn't even have a battery on it. When light button is pushed lights come on and hour meter lights up with hours displayed. Will not retrieve codes or say none when light button is held.

Things checked and tried
1.battery
2.put a good key switch panel in it (key style with warning lights above key)
3.big fuse above battery have 12v on both sides of fuse
4.fuses and relays in fuse box. Checked fuses with test light and switched relays with good one
5.inspected harness plug below cab that feeds cab for rubbed wires
6.checked in behind left right and center panel for rubbed wires
7.tried extra left hand panel had
8.have 12v on red/white wire going into key switch panel
9.visually looked at all grounds
10.cleaned battery post and and terminals on battery cables at battery side
11. I zip tided fuel shut off solenoid and crossed starter and it fired right up but still no power to instrument cluster or traction lock solenoid or hydraulic lock.

Looking for any advice on what to try, sorry for long post. Thanks in advance

 

[willie59]

A couple of questions Bcatdaddy, is this a standard control machine, no advanced hand control or selectable joysticks? Machine serial number?

 

[Bobcatdaddy]

Yes it's standard controls. Serial is #512258939

 

[willie59]

Thanks. It's near check out time for me, but I'll keep you in mind. Maybe crewchief will jump in here as well.

 

[Bobcatdaddy]

Thanks willie, all advice is greatly appreciated.

 

[crewchief888]

could be a bad LH panel.

check for power & ground at the LH panel harness connector.

common points in the harness to check are

cab harness behind the LH panel where it goes up over the panel mount
cab harness where it "bends" at the back of the cab
cab harness where it plugs into the main harness
main harness at the same connector.

when checking for power, dont use a seperate (known good ground), you may have a partially broken wire IN the harness.


:drinkup

 

[Bobcatdaddy]

Thanks for the reply crewchief! Forgot to mention that I tried a left hand panel I had and it didn't change anything. Do you know which wire should have power at Lh panel or should I just check all to see if one has 12v and should only 1 wire at Lh panel have 12v? I'll check the points you mentioned and get back with results. May be a couple days before I can get to it though. Should there be only 1 wire that feeds cab wiring harness with 12v constant? Probably stupid question on my part, but when you say don't use a known good ground, do u mean to use a ground wire in the harness that I'm checking? Thanks again for the replies, there greatly appreciated!!

 

[crewchief888]

Thanks for the reply crewchief! Forgot to mention that I tried a left hand panel I had and it didn't change anything. Do you know which wire should have power at Lh panel or should I just check all to see if one has 12v and should only 1 wire at Lh panel have 12v? I'll check the points you mentioned and get back with results. May be a couple days before I can get to it though. Should there be only 1 wire that feeds cab wiring harness with 12v constant? Probably stupid question on my part, but when you say don't use a known good ground, do u mean to use a ground wire in the harness that I'm checking? Thanks again for the replies, there greatly appreciated!!

@ the LH panel connector there should be 1 wire (red or red/white) that has 12v on it at all times. when testing use the ground in the harness ( black wire) not a seperate ground to the frame.

:drinkup

 

[Bobcatdaddy]

Didn't have a chance to check it today. I'll try to check it Monday weather permitting. Does the Lh panel send power to Rh panel? If I have good power and ground to those components, any idea on what to check after that? Thanks again for your time and help

 

[willie59]

Just offering some info to clarify. The left panel has a mini computer in it, it communicates with the main ECU in the lower frame that controls the machine. When you power up the machine with the right panel, that info goes through the computer in the left panel. When you hit start on the right panel, that info goes through the computer in the left panel. Everything that happens in the cab comes from or goes through the computer in the left panel because it communicates with the main ECU.

 

[Bobcatdaddy]

Thanks willie, I'll keep that in mind. Always easier working on or trouble shooting something when you have a better idea of how it works.

 

[Bobcatdaddy]

I checked for rubbed or torn wires in all places you mentioned, and also checked for good voltage. Wires look ok, and have 12v to and out of main harness under cab and also have 12v at Lh and Rh panels. Any idea on where to go from here? Thanks again for the help

 

[crewchief888]

I checked for rubbed or torn wires in all places you mentioned, and also checked for good voltage. Wires look ok, and have 12v to and out of main harness under cab and also have 12v at Lh and Rh panels. Any idea on where to go from here? Thanks again for the help

have you checked the connectors @ the main controller?

removed the switch power relay and check the contacts inside the fuse block.

right now i'm suspecting a bad controller. it's hard to tell without beig there and beig able to plug in with service software

:drinkup

 

[Bobcatdaddy]

have you checked the connectors @ the main controller?

removed the switch power relay and check the contacts inside the fuse block.

right now i'm suspecting a bad controller. it's hard to tell without beig there and beig able to plug in with service software

:drinkup

After last post I tried a Lh and Rh panel off a buddy's bobcat that are good with no change. By main controller are you meaning the main computer under cab? Haven't checked contacts inside fuse block, but have tried different relay.
Stupid question, but how do I check contacts inside fuse block? I really appreciate your time and help!!

 

[crewchief888]

After last post I tried a Lh and Rh panel off a buddy's bobcat that are good with no change. By main controller are you meaning the main computer under cab? Haven't checked contacts inside fuse block, but have tried different relay.
Stupid question, but how do I check contacts inside fuse block? I really appreciate your time and help!!

main cotroller, it should have 4 multi pin connectors on it.

unplug the fuses/relay and look inside where they make contact with the relay spades.
if they are burned /corroded/ damaged you'll be able to see
a really bright LED flashlight helps.

:drinkup

 

[Bobcatdaddy]

I will check this stuff tomorrow and get back with results. Any way to check main controller? If I end up needing a new one will this be something the dealer will have to reflash?

 

[crewchief888]

I will check this stuff tomorrow and get back with results. Any way to check main controller? If I end up needing a new one will this be something the dealer will have to reflash?

no way to check it without (dealer only) service software. and it's only a way to try to see whats going on looking at stored fault codes, and monitoring the system.

dealer has to program the controller on the machine.


:drinkup

 

[Bobcatdaddy]

Ill check connectors at controller and contacts at fuse block tomorrow if all that checks out good bout have to be a controller doesn't it?

 

[Bobcatdaddy]

Connectors and contacts at fuse block look ok, not sure if it matters but Alt& kits fuse doesn't have power and fuse is good. Does this have any correlation to my problem? Called bobcat it'll cost me $300 just for them to show up and then $102 per hour to look at machine:spaz So I guess I'll try and do a little more trouble shooting. Any more ideas?

 

[Bobcatdaddy]

Not sure I done it, but messing around with the light button trying to get a code or something I got it to say "input". Does this shed any light on the issue?