T770 electrical issue

[conconinc]

I have a 2015 T770 bobcat that has an electrical issue with the hydraulic release on the bob tach. It keeps blowing fuses and does it even if your not using it. I have taken it to the dealer and they changed the wiring harness that goes under the engine but did not solve the problem. They said it is probably in the main wiring harness somewhere and no way of locating where so I would have to replace the whole harness which isn't very cheap. They already charged me $600.00 dollars for swapping out something that didn't fix the problem. Just wondering if anyone else has had this issue and may have a solution or where in the harness it might be there are no nicks in the harness anywhere and all of the hard casing is still intact.

 

[flyerdan]

You might have a nose about in the manual thread, the first link has some Bobcat electrical diagrams. There is also a book for an A770, but it's in a .rar that appears to be corrupted; at least that's what my winrar says, and it extracted another file right afterward so it's working ok.

I'm wondering if it might be in the component itself rather than the wiring going to it. Especially since everything looks intact and undamaged; a bad toaster will trip a breaker even if all the cords and outlet is good.

 

[Tazza]

You might have a nose about in the manual thread, the first link has some Bobcat electrical diagrams. There is also a book for an A770, but it's in a .rar that appears to be corrupted; at least that's what my winrar says, and it extracted another file right afterward so it's working ok.

I'm wondering if it might be in the component itself rather than the wiring going to it. Especially since everything looks intact and undamaged; a bad toaster will trip a breaker even if all the cords and outlet is good.

I have to disagree with their "no way of locating it" there is always a way, it's just not a way they wish to spend time on looking for a short.
It puzzles me when you say it blows fuses even when not running, i'd have thought no power would be there till it's turned on.
I'd check your fuse/relay box to start off with, look for water entry. Then start checking around at any point that the harness touches the frame, these are possible chafing points that the insulation could be worn through and short out.

 

[conconinc]

I have to disagree with their "no way of locating it" there is always a way, it's just not a way they wish to spend time on looking for a short.
It puzzles me when you say it blows fuses even when not running, i'd have thought no power would be there till it's turned on.
I'd check your fuse/relay box to start off with, look for water entry. Then start checking around at any point that the harness touches the frame, these are possible chafing points that the insulation could be worn through and short out.

Sorry Tazza I should of said when you are not operating the bobtach release the machine is running when it happens it only happens when you are moving the machine and not operating the bobtach release. If you replace the fuse and just sit still it works fine and may work after using the machine for awhile then it will just blow a fuse. It usually doesn't take long to blow a fuse ten minutes or sometimes even less it seems like the movement makes blow the fuse. We have checked all the wiring for chafing and the fuse box shows no sign of moisture loss. Well your right the dealer would've kept looking but they said they weren't sure how much time they would have into it and couldn't give me a price and that I may have to change the main wiring harness. That's expensive I was hoping I might find someone that had the same issue and give me a clue where it might be in the harness. Thanks for your response when we have time between jobs we will keep looking for it.

 

[conconinc]

Sorry Tazza I should of said when you are not operating the bobtach release the machine is running when it happens it only happens when you are moving the machine and not operating the bobtach release. If you replace the fuse and just sit still it works fine and may work after using the machine for awhile then it will just blow a fuse. It usually doesn't take long to blow a fuse ten minutes or sometimes even less it seems like the movement makes blow the fuse. We have checked all the wiring for chafing and the fuse box shows no sign of moisture loss. Well your right the dealer would've kept looking but they said they weren't sure how much time they would have into it and couldn't give me a price and that I may have to change the main wiring harness. That's expensive I was hoping I might find someone that had the same issue and give me a clue where it might be in the harness. Thanks for your response when we have time between jobs we will keep looking for it.

https://www.heavyequipmentforums.com/attachments/bobcat-t770-wiring-diagram-pdf.202361/ I couldn't figure out how to upload the wiring diagram on here so i am putting a link where I posted it on another forum if this would help anybody

 

[Tazza]

https://www.heavyequipmentforums.com/attachments/bobcat-t770-wiring-diagram-pdf.202361/ I couldn't figure out how to upload the wiring diagram on here so i am putting a link where I posted it on another forum if this would help anybody

It has to be a wire touching the frame, when you move it contacts and blows, sadly you will need to look at all the places the harness touches the frame, see if there is a wire that has worn insulation.
I have an S250 that has a gremlin too, i need to get time to sit down and inspect my entire harness, not looking forward to that one bit.

 

[foton]

It has to be a wire touching the frame, when you move it contacts and blows, sadly you will need to look at all the places the harness touches the frame, see if there is a wire that has worn insulation.
I have an S250 that has a gremlin too, i need to get time to sit down and inspect my entire harness, not looking forward to that one bit.

maybe you could open everything up and turn the lights out and connect the fuse that is blowing and look for a spark or put a volt meter set to ohms to ground and the other lead to the dead fuse position and move the harness around and look when the meter changes readings.

 

[Tazza]

maybe you could open everything up and turn the lights out and connect the fuse that is blowing and look for a spark or put a volt meter set to ohms to ground and the other lead to the dead fuse position and move the harness around and look when the meter changes readings.

That's not a bad idea at all.

 

[ozarkag]

That's not a bad idea at all.

Or invest in a Power Probe ECT. Pays for itself on the first job. Plug into fuse that blows, receiver will trace the wire through harnesses. Shake and move harness, the transmitter will tone if short to ground changes.

 

[Tazza]

Or invest in a Power Probe ECT. Pays for itself on the first job. Plug into fuse that blows, receiver will trace the wire through harnesses. Shake and move harness, the transmitter will tone if short to ground changes.

I have never used a power probe, yet a mad mate did buy one. Are they really that good at finding issues? i have a gremlin that takes all power out on my S250, if i grab the harness and shake it, it works. I need to get time to actually trace the cables and find the issue...