Dangerous Electrical Problem

[JackConrad]

     Recently, I read a post about a dangerous electrical problem that occurred when the insulation on a heavy cable in the engine compartment of an MCI wore through causing a short and nearly an engine fire.  
    When I recently had our engine/transmission out for a transmission repair, I decided to inspct the cable that runs through the engine cradle. I think this configuration is used on most, if not all, MC 5, 7, 8, and 9s. The cable enters the cradle near ther starter and exits near the rear of the cradle (towards the front of the bus). I found the insulation worn through at the point that the cable exits the rear of the cradle. Forunately, I did not see evidence of arcing, but I consider myself extremely lucky. My new cable does not run through the cradle, but is secured to the outside of the cradle.  
      If you own one of these model MCIs, I would highly recommend you check this cable.  Should it short out the only way to remove the power from it is the OEM battery disconnect switch in the battery compartment.  Jack

[robertglines1]

No matter what brand of coach you have if its old its likely to be cracked (insulation) shorts cause fires..can do in expensive batteries,,,and not least   leave us on the side when we would like to be going...I know your post was MCI intended but reminds us all of a potential prob..thanks  Bob

[Busted Knuckle]

Jack & Bob,
That's great advice. And FWIW that cable set up was also used on the 96 & 102 A's ! I can't vouch for the B's, C's or D's. But my guess is yes there also!
  BK 

[cody]

Another spot that should be checked is on iggles where the cables go thru the wall by the start batteries next to the a/c compartment, there is a potential chaff point there if the grommet that protects them is gone and the metal sides of the hole is exposed.

[Ed Hackenbruch]

Sigh,.......one more thing to add to my list.

[Tom Y]

I removed my cable from the cradle also. I also got some 3/8 thick nylon and put holes in for battery cables thru a compartment. No metal if it does rub thru.  Tom Y

[edvanland]

Thanks for the info. When I put a electrical cable through a metal bulkhead I use a old piece of garden hose. Works great and cheap.  I get a new supply of old garden hoses each spring when I have to replace my old ones.
ED
MCI 7

[belfert]

I had some pretty bad corrosion issues with the wires to my starting batteries when I wasn't keeping them charged over the winter.  I had to have a new end put on one cable and I had to get a replacment made for another.  The lugs were eaten right through.  I hope this spring I won't have issues with the Battery Tender hooked up now.

Ed, if you need new garden hoses every year you must buy some cheap ones.  I bought some with lifetime guarantees and they look good as new five or six years later.

[compedgemarine]

on my Eagle I didnt have any chaffing problems but on more than half of the cables had the insulation cracked so bad I could pull it off by hand. I replaced all the cables from the batteries to the alternator to the starter and all the switches. $400 plus of cable, ends, shrink wrap etc. but I doubt I will ever need to change it again while I own it.
steve

[Ed Hackenbruch]

Brian,  he lives in Az. The sun is hard on garden hoses, especially if you are there year around.  One summer is about the same as 5-6 elsewhere.

[FloridaCliff]

Just to add to what Jack said about the MCI issue.

For all the GMC folks,  While working in the old A/C compartment fitting my new generator in. I found that the insulation was cracking on the 0000 cable running from the start batteries to the engine compartment.  I had been advised that others had found this upon doing a complete inspection.

Mine looked good until I went to move the cables and they cracked and chunks of insulation fell off.

I took this opportunity to move the start batteries back to the old compressor space and ran new 00 cable up front for my house batteries.

Cliff 

[Nick Badame Refrig/ACC]

Hi Jack,

Real good advice! Thanks..

Hay, I don't have my glasses with me. Did you snap a picture of one of those Florida black snakes again?

Nick-

[PCC]

My Prevost, the seller reconnected the batteries with the 12v lead leaving the batteries in the wrong direction. The wire headed directly toward the chassis, and then turned back to the exit opening.

As I closed the drawer, one day, I heard an electrical miss, so I shut everything down and when I opened the drawer, the insulation on the 12 v wire was burning. I was able to put the fire out and remain thankful that it was not as bad as it cold have been.

This was not a new problem, because I found a 2" hole burned into the bus frame where the wire had been touching, probably while I had been driving.

Could have burned the coach, or exploded the batteries. I feel so blessed that nothing actually happened.

I have so much to be thankful for.

I have installed warnings to monitor that there are no wires to ground that should not be.