2006 Cat 277B Electrical Problems

[BradinTX]

I bought this machine about 2 months ago and it ran great. About 2 weeks ago I got into it to do some work and it was dead. I hooked my truck up to the battery and the power and guages came on but it just clicked when I tried to start it so I assumed the battery was totally dead.

Went ahead and put in a new battery and it cranked right up. I drove down to where I was going to work and all of the electrical gauges went out. Machine was still running fine so I worked with it for about 20 minutes and started smelling plastic burning. Turned off the machine and got out to check the engine compartment and sure enough the negative post on the battery was melted and the top of the battery had ruptured.

I put in another new battery but the gauges still didn't work this time. Machine ran fine. Worked with it for about an hour checking the battery on occasion and it never was warm. Ran it for about another 10 minutes and started smelling the same burning so immediately turned off the machine went back and checked and the battery was extremely hot but luckily hadn't melted yet.

Started researching what could be causing the problem. I checked all the fuses and the gauges fuse was blown. I replaced the gauges fuse and cranked it up and everything came back on for about 5 seconds and then it blew the fuse again and the guages panel started smoking.

Can anyone point me towards what would be causing this. Obviously something is shorted out somewhere or grounded incorrectly. I have no clue.

 

[92U 3406]

From what I remember the wiring on those older Cat skid steers isn't the greatest. Seem to always have issues where the harness runs from the cab down along the plastic hydraulic tank.

 

[BradinTX]

Okay. Looking through the forums I downloaded the wire schematic someone had posted, so it looks like I'm just going to have to trace down the problem. Just not sure where to start. This is is my first machine, so I'm learning as I go. Haha.

Was hoping someone could confirm that what's happening sounded like a short or what.

 

[92U 3406]

To smoke the battery like that it'd have to be pulling some major amps. A short to ground on a branch circuit like worklights or radio would burn that circuit up long before you'd cook a battery I would think.

 

[BradinTX]

That's what's throwing me for a loop. What would kep roasting batteries like that. Haven't seen that in my 43 years in any other vehicles or equipment. But something is definitely drawing power because when I went to work with it again this weekend the new battery was dead too.

 

[heymccall]

My money is on a defective battery negative cable. If it's melting the battery at the cable connection, the wire to lug crimp integrity is questionable.