Fire

P

patrick flowers

New member
Sep 19, 1997
1,460
0
0
>
> My question is this: this is a long run of very heavy wire. I replaced
> it with 2/0 and conduit. How big of a fuse do I need to put back
> at the house battery to allow it to start the engine yet have it
> blow when things aren't cool.

Jim B. and I had this conversation at Marion. I think he said 100amp
breaker. Hopefully he'll check his email and correct me if I got it
wrong. Proper sizing is important as these breakers are often "one
shot" deals due to the large amount of DC current they must overcome.
The resultant arcing toasts the contact surfaces.

> I thought this thing was not hot unless I was in the "Boost" mode.

Nope - "Boost" mode just ties the two cables together at the relay in
the engine compartment. The cable from the rear is hot all the time.

Patrick
- --
Patrick Flowers
Mailto:patri63

The GMC Motorhome Page
http://www.gmcmotorhome.com
 
>GMCers
>
>I have a sad tale to tell. I just bought some cabinets from a guy who
>has a burnt out GMC. The ad was in the latest GMCMHMP.
>The coach caught fire when the cable from the house bat that runs
>down the driverside of the rig to the isolator rubbed through the
>insulation------shorted out and caught fire. The fire burned up the
>cockpit drivers seat side wall and end cap in cockpit. There is a
>service bulletin on this problem. You are supposed to put the
>cable in the plastic conduit. Well, after talking to him I decided to
>take a look at my lady. It was easy because everything is out anyway.
>The cable where it crosses over the frame in the front was dry and
>hard.
>When you pulled on it cracked and poped. Then I went inside.
>Just behind the drivers seat where the cable begins to travel down
>the sidewall there it was. The conduit and wire had worn through.
>There was green crud where the copper had been exposed. No
>signs of arcing or anything just bare wire. Then I found a place
>where mice had eaten through everything.
>
>My question is this: this is a long run of very heavy wire. I
>replaced
>it with 2/0 and conduit. How big of a fuse do I need to put back
>at the house battery to allow it to start the engine yet have it
>blow when things aren't cool. I thought this thing was not hot
>unless I was in the "Boost" mode. Somebody talk to me.
>
>Take Care
>Arch 76 GB IL
>
This is kind of scary, Arch! I guess we should definately be looking but
it won't be so easy for most of us. I acn't help with fusing but surely
others can.

Is it possible to get the data on this burned coach for the Registry?

Thanks for the heads up!

Dave Greenberg
GMC Motorhome Registry
200 MacFarlane Dr PH4
Delray Beach, FL 33483-6829
 
It appears that the house battery cable on some coaches from 1974 to
1977 serial 1456 had an abrasion problem. This was noted in dealer
service bulletin #77-TM-4. This is also noted in GMC Motorhomes
International Newsletter Issue 24 where the "fix" proceedure is
described. My coach falls in thes era --- going to check it out PDQ.
Gary '77 Kingsley North Bend, Oregon Coast
 
Please post what the fix is. I replace part of the cable this summer,
but I do not know the routing when it leaves the left side of the engine
compartment.

Eric Tipton
etipton

-----Original Message-----
From: Gary Miller [mailto:grizzly]
Sent: Tuesday, November 03, 1998 2:39 PM
To: GMC Motorhomes
Subject: GMC: FIRE

It appears that the house battery cable on some coaches
from 1974 to
1977 serial 1456 had an abrasion problem. This was
noted in dealer
service bulletin #77-TM-4. This is also noted in GMC
Motorhomes
International Newsletter Issue 24 where the "fix"
proceedure is
described. My coach falls in thes era --- going to
check it out PDQ.
Gary '77 Kingsley North Bend, Oregon Coast
 
Another good place to check for any type of wear (Chaffing from vibration)
on that cable is right as it comes off the solenoid and goes down to the
cross member in front of the radiator. If you have one / two batteries in
the front the first one closest to the grill may (I say May) chafe the
cable if the plastic conduit is not covering it all the way up to the
solenoid. I tied the cable off with a tie strap to the oil fill tube so
as to ensure this would not happen. That electronic cleaner does a good
job on the terminals too. Chuck

> It appears that the house battery cable on some coaches from 1974 to
> 1977 serial 1456 had an abrasion problem. This was noted in dealer
> service bulletin #77-TM-4. This is also noted in GMC Motorhomes
> International Newsletter Issue 24 where the "fix" proceedure is
> described. My coach falls in thes era --- going to check it out PDQ.
> Gary '77 Kingsley North Bend, Oregon Coast
 
As I recall it is a 100 amp breaker that sits inside the battery
compartment, just above the batteries. It is used when you throw the
booster on to let you have enought to start engine.

Al Chernoff

> >
> > My question is this: this is a long run of very heavy wire. I replaced
> > it with 2/0 and conduit. How big of a fuse do I need to put back
> > at the house battery to allow it to start the engine yet have it
> > blow when things aren't cool.
>
> Jim B. and I had this conversation at Marion. I think he said 100amp
> breaker. Hopefully he'll check his email and correct me if I got it
> wrong. Proper sizing is important as these breakers are often "one
> shot" deals due to the large amount of DC current they must overcome.
> The resultant arcing toasts the contact surfaces.
>
> > I thought this thing was not hot unless I was in the "Boost" mode.
>
> Nope - "Boost" mode just ties the two cables together at the relay in
> the engine compartment. The cable from the rear is hot all the time.
>
> Patrick
> --
> Patrick Flowers
> Mailto:patri63
>
> The GMC Motorhome Page
> http://www.gmcmotorhome.com
 
Disregard my last... it was a 60 amp breaker. In my coach, I have installed
a 100 amp breaker because I use the 100 amps to run my inverter when it is
using the microwave, and the 60 amp would kick it off. The sixty is fine for
most jobs but when you are running a 1500/2000 watt inverter, you need all
the juice you can get. Even then, the 100+ amps in the batteries will only
run that load for about 30-40 min max. So, I use it sparingly when I don't
want to run the generator, and when the wife wants to run the computer and
other small stuff.

Al chernoff

> As I recall it is a 100 amp breaker that sits inside the battery
> compartment, just above the batteries. It is used when you throw the
> booster on to let you have enought to start engine.
>
> Al Chernoff
>

>

> > >
> > > My question is this: this is a long run of very heavy wire. I replaced
> > > it with 2/0 and conduit. How big of a fuse do I need to put back
> > > at the house battery to allow it to start the engine yet have it
> > > blow when things aren't cool.
> >
> > Jim B. and I had this conversation at Marion. I think he said 100amp
> > breaker. Hopefully he'll check his email and correct me if I got it
> > wrong. Proper sizing is important as these breakers are often "one
> > shot" deals due to the large amount of DC current they must overcome.
> > The resultant arcing toasts the contact surfaces.
> >
> > > I thought this thing was not hot unless I was in the "Boost" mode.
> >
> > Nope - "Boost" mode just ties the two cables together at the relay in
> > the engine compartment. The cable from the rear is hot all the time.
> >
> > Patrick
> > --
> > Patrick Flowers
> > Mailto:patri63
> >
> > The GMC Motorhome Page
> > http://www.gmcmotorhome.com
 
Arch, is this cable INSIDE thecoach or does it run outside and underneath??

Thanks for the warning

ALAN
78 Royale

> GMCers
>
> I have a sad tale to tell. I just bought some cabinets from a guy who
> has a burnt out GMC. The ad was in the latest GMCMHMP.
> The coach caught fire when the cable from the house bat that runs
> down the driverside of the rig to the isolator rubbed through the
> insulation------shorted out and caught fire. The fire burned up the
> cockpit drivers seat side wall and end cap in cockpit. There is a
> service bulletin on this problem. You are supposed to put the
> cable in the plastic conduit. Well, after talking to him I decided to
> take a look at my lady. It was easy because everything is out anyway.
> The cable where it crosses over the frame in the front was dry and hard.
> When you pulled on it cracked and poped. Then I went inside.
> Just behind the drivers seat where the cable begins to travel down
> the sidewall there it was. The conduit and wire had worn through.
> There was green crud where the copper had been exposed. No
> signs of arcing or anything just bare wire. Then I found a place
> where mice had eaten through everything.
>
> My question is this: this is a long run of very heavy wire. I replaced
> it with 2/0 and conduit. How big of a fuse do I need to put back
> at the house battery to allow it to start the engine yet have it
> blow when things aren't cool. I thought this thing was not hot
> unless I was in the "Boost" mode. Somebody talk to me.
>
> Take Care
> Arch 76 GB IL
 
Alan

I have a 78 Royale, side bath and am just reinstalling the cabinets and
countertop behind the drivers seat. I also had to redo some of the paneling
and did not see any battery cables in this area. Possibly the transmode has a
different wiring layout.

Phil
78 Royale
 
Patrick,
Please unsubscribe me as I'll be gone for a couple of months I hope. Back @
xmas good Lord willing and the creeks don't rise.
Best regards,
Sam Pickens
 
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