270 A alternator ground cable repair

[hexspeed]

The lug on the 2/0 ground cable to the back of my M380 alternator snapped. It looks like it has been replaced before, so I have no slack to put a new lug on. It travels down, under the engine, then back up to a chassis ground stud above and forward of the chassis batteries -- estimate 15 feet.

Alternative 1: Cut all the wire ties around and under the engine that bind it and all the hydraulic hoses into a huge bundle to see if I could gain a couple of inches -- really a PIA to do that and uncertain whether I would get enough slack.

Alternative 2: I have a spool of 1/0 welding cable I could use for a new run. According to which chart I read, 1/0 is either OK or at the margin for 270 amp over the length I need. BUT, the 270 amp rating is peak -- probably doesn't ever run at that level for any length of time, so probably adequate.

Alternative 3: Get a short section of 2/0 and use a 2/0 copper crimp splice with a new lug. Know that splices are never optimal, but would solve the problem.

Alternative 4: Run all new 2/0. Probably $100 - $150 for a new cable depending on whether I build it.

I'm leaning towards #3 -- hangup is having to buy a bigger crimper (I've seen all the recent posts about which one to buy).

If it were your bus, what would you do?

Thanks
Jim

[Russ Beardsley]

Jim,

Why does the alternator need to be grounded 15 feet away? Isn't there are closer location? Also, remember folks I'm a Nurse not an electrician.

[Dieselbird01]

Originally Posted by hexspeed

The lug on the 2/0 ground cable to the back of my M380 alternator snapped. It looks like it has been replaced before, so I have no slack to put a new lug on. It travels down, under the engine, then back up to a chassis ground stud above and forward of the chassis batteries -- estimate 15 feet.

Alternative 1: Cut all the wire ties around and under the engine that bind it and all the hydraulic hoses into a huge bundle to see if I could gain a couple of inches -- really a PIA to do that and uncertain whether I would get enough slack.

Alternative 2: I have a spool of 1/0 welding cable I could use for a new run. According to which chart I read, 1/0 is either OK or at the margin for 270 amp over the length I need. BUT, the 270 amp rating is peak -- probably doesn't ever run at that level for any length of time, so probably adequate.

Alternative 3: Get a short section of 2/0 and use a 2/0 copper crimp splice with a new lug. Know that splices are never optimal, but would solve the problem.

Alternative 4: Run all new 2/0. Probably $100 - $150 for a new cable depending on whether I build it.

I'm leaning towards #3 -- hangup is having to buy a bigger crimper (I've seen all the recent posts about which one to buy).

If it were your bus, what would you do?

Thanks
Jim

Hi Jim,

It’s bothersome that it appears to have happened more than once! That needs to be looked into..

A well done splice (covered with good waterproof heat shrink) would most likely be acceptable… however, your conscience will probably keep nagging you until you put in a new cable.

[sfedeli]

Jim, Happy to make you a cable with tinned lugs. You just need to let me know the size of the hole in the eyelet(s). I can use 4/0 or 2/0 with adhesive lined shrink tubing if you desire it. I use a Greenlee 1990 hydraulic crimper and coat the wire ends with Kopr Shield prior to crimping. Won't be anywhere near $100 for a short cable. Figure around $10 a foot for 4/0 and $4 per lug plus shipping.

[hexspeed]

Originally Posted by Russ Beardsley

Jim,
Why does the alternator need to be grounded 15 feet away? Isn't there are closer location? Also, remember folks I'm a Nurse not an electrician.

Good question -- came from factory that way. The ground stud it goes to also connects directly to the battery ground and a couple of other heavy ground cables that feed other systems. Best guess it is designed this way to eliminate any "bad ground" problems that seem to be the source of many Wanderlodge electrical issues. It would certainly be simpler to add another ground stud to the frame that's about a foot from the alternator, but I'm not sure I want to risk any issues that might create.

[hexspeed]

Originally Posted by Dieselbird01

Hi Jim,

It’s bothersome that it appears to have happened more than once! That needs to be looked into..

A well done splice (covered with good waterproof heat shrink) would most likely be acceptable… however, your conscience will probably keep nagging you until you put in a new cable.

I think this time, the guys I had helping me reinstall the CAC, radiator, fan, hydraulics and coolant maze may have snagged it. I didn't find it until last week when I was under the engine cleaning up some wire ties from the radiator job - no clue how long it's been dangling. I tried pulling it back up to the alternator and it was a VERY tight fit. I think adding some slack to take tension off the lug would be the solution.

And, you're right, a splice would bother me no matter how well done it was!

[hexspeed]

Originally Posted by sfedeli

Jim, Happy to make you a cable with tinned lugs. You just need to let me know the size of the hole in the eyelet(s). I can use 4/0 or 2/0 with adhesive lined shrink tubing if you desire it. I use a Greenlee 1990 hydraulic crimper and coat the wire ends with Kopr Shield prior to crimping. Won't be anywhere near $100 for a short cable. Figure around $10 a foot for 4/0 and $4 per lug plus shipping.

Shane: Attractive offer! Cable is about 15 feet of 2/0 -- still need to measure (it may be closer to 12' after just taking a better look). Lugs are 3/8" eyelets. Not sure how much that would be with shipping to Columbus, OH, but probably getting close to my earlier estimate with all that weight.

Thanks
Jim

[Shawnthegrasshopper]

Put Shane to Work!
He’s looking for Something to Do!

[sfedeli]

I just do not see how 15' of cable is needed. Surely there is a frame member or chassis brace closer than that. When I re-plumbed my engine compartment with new hoses a few years ago, I removed close to 12' of hose. BB had some "issues" with "less than efficient" use of materials- except when it came to wiring; then they often used cable that was far too small for the application. I just re-made a cable for an owner with a '99 LXi. Thieir 50DN alternator only had what appeared to be a 6 or even 8 gauge wire from the alternator to the engine battery stud- but it was 3' long! The new one is about 18" long and 2/0 gauge.

[hexspeed]

Shane: here’s a pic. If I follow the factory install, cable goes down 2’ from alternator to the big bundle of hoses that cross 3’ under the engine to other side, then forward along the frame rail ~3’, then up 3’ to the ground stud above the battery bank. So total 11-12’ — need to crawl under to be more precise. These cables are definitely not undersized!