773 won't start

Electronic control. When I push start, it just gives one heavy clunk. Battery is brand new and fully charged. Replaced the starter/solenoid, so that's not it. Battery/starter connections are tight. The electronic control was replaced just a couple years ago and has maybe 100 hours of use on it. After about 50 tries it will eventually start like nothing was wrong, but when I shut it down and try to restart I'm back with the same problem.

Any ideas?

Sounds like a bad, (shaft bearing),
or misaligned, (improperly shimmed),
or wrong (tooth), starter to me.

It could be the contacts in the starter solenoid if it's a Nippon Denso. I had my starter rebuilt with OEM parts because it was very intermittent. Then with the rebuilt starter started having the same problem. Was going to take it back for warranty but took the cover off and saw the big copper contacts were black. Took it apart and cleaned with sand paper and fixed the problem. Have heard it's common on ND starters. It's acting up a bit again and I think a low battery contributes to it. Click, click, click a dozen times before it engages.

I don't have any clue, but you can make up some long test leads with some alligator clips and wire, then hook up to the solenoid signal wire, and one to the big cable going into the starter. Use a voltmeter in the cab while you click it, to see where the power is and isn't going. Then you can at least tell if it's the starter, or the "control" wiring.

have you checked/replaced the starter relay?
cleaned the battery cables?

most "no start" problems can be traced right back to the battery.

Battery cables are clean. I did not replace the relay though. Where is it located?

On a G Series it would be in the fuse box located between your legs when you're sitting in the seat. But to repeat what others have said, most of the time the problem you describe, hit start and "clunk", no crank, are related to the battery or cables. Not often, and maybe not your problem, but I have seen battery terminal connections that are clean and tight, but the problem was the cable connection to the battery lug terminal. When you press the start button and get that "clunk", do all the display functions go dark as well?

All the display functions stay lit.

I'll double-check the cable-to-terminal connections, but I recently replaced the battery and the cables felt solid. It's a brand new Interstate with a lot of CCA, so plenty for this application.

The directions for installing the starter also say to "check the neutral start switch, located on the transmission or at the end of the shift lever mechanism. This switch can also cause problems if it malfunctions." I have foot controls, so I suspect mine would be located on the transmission(?). I don't know if this could be the problem, what it looks like, or how to find it.

Not sure if it's related, but one other problem I've always had with this machine since buying it 3 years ago was that it sometimes didn't want to shut off. Eventually that sometimes turned into always. I would always have to open the back door and push the fuel shutoff solenoid shaft over. And recently now that I'm having problems starting it, I noticed that the fuel shutoff solenoid won't stay open (for run mode). I installed a brand new solenoid, but that didn't help. I had to jam a combination wrench into the bracket to hold the solenoid open. If I got it running, the new solenoid wouldn't stay open without the wrench in there. But even with the solenoid held open, I also still get the clunk with no start...until about the 50th try and then it will start.

sounds like corroded, rusty fuses and/or relays to me.
or if you installed a reman starter, it's a POS.
we dont sell ANY reman's, especially for service repairs, unless it's the ONLY alternative.

RichTech said:

, I also still get the clunk with no start...until about the 50th try and then it will start.

Click to expand...

What do you suppose the clunk is?
Starter gear trying to engage the flywheel?

First thing I'd do, is to loosen the starter, re-position it and bolt it tight.
Shimming might be required.

crewchief888 said:

sounds like corroded, rusty fuses and/or relays to me.

Click to expand...

Don't forget vermin damage to wiring as a possibility as well.

The clunk is definitely the starter engaging and then immediately disengaging.

I inspected all the battery cables, cleaned the contacts, and made sure they were tight. I inspected all the wires in the engine bay as deep as I could see, removed the interior pillar covers to check the control wiring, and removed the exterior side hatch covers between the wheels to inspect all the wiring underneath...no critter damage. The 7 relays were all the same, so I swapped them around to see if one might be bad for the starter. I pulled and checked all the fuses.

I have a feeling this could be the computer board. Second guess would be the neutral start switch. Third guess would be the right side control (although that was just replaced about 2 years ago). The reason I guess the computer is because the problems progressively got worse, and that I'm pretty sure the fuel shutoff solenoid is getting no input at this point.

there isnt a neutral safety switch on a bobcat...

by any chance did someone wire in a starter kill switch at some time?

Was at the Bobcat dealer today and they said those directions with the starter were generic and there's no neutral safety switch.

I'm out of options. I guess I'll have to bring it in and pay the $115/hr to have them figure out what it is.

willie59 said:

On a G Series it would be in the fuse box located between your legs when you're sitting in the seat. But to repeat what others have said, most of the time the problem you describe, hit start and "clunk", no crank, are related to the battery or cables. Not often, and maybe not your problem, but I have seen battery terminal connections that are clean and tight, but the problem was the cable connection to the battery lug terminal. When you press the start button and get that "clunk", do all the display functions go dark as well?

Click to expand...

What does it mean if all the lights go out mine will light up when I put the key in the start position then I try to start it and click everything goes out and its like the key was off

Izaak Madera said:

What does it mean if all the lights go out mine will light up when I put the key in the start position then I try to start it and click everything goes out and its like the key was of

Click to expand...

Bad battery cable connection is usually same symptoms