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Home » Public Forums » GMCnet » Re: [GMCnet] Electrical Short found but it wasn't easy
Re: [GMCnet] Electrical Short found but it wasn't easy [message #315041] Thu, 23 March 2017 11:35 Go to next message
THOMAS R WHITTON is currently offline  THOMAS R WHITTON   United States
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I'm re-posting this because for some reason it didn't appear after I first tried to post it a few days ago. 
Please thank Yahoo if you see question marks in strange places...
A sincere thanks for everyone's suggestions in helping to resolve this problem.
I finally found the short in the right tail light, brake and emergency flashers.  Call me "Speedy."  It only took a few hours most days for over two weeks to trace the short without success.  In the end, it turned out to be caused by a hidden crushed wire running between the body and frame.  It was a bad wiring job done by a local RV store soon after I bought the GMC in 2001.  Their work was both expensive and bad.  Anyway, I learned a long time ago not to use them but, unfortunately, their bad work has lived on.  The crushed wire ran between a 10-wire connector in the generator compartment to the trailer connection under the coach.  The good news is I learned how to trace shorts but I'm not going to come out of retirement and go into Electrical Short Tracing.  I took umpteen resistant readings from front to back and bought a cable tracer from Harbor Freight.  I also put together a light to plug into the fuse socket that lit when a short was present and did not lite when there was no short in the circuit.  These tools helped determine that the short was somewhere between the 10-point connector in the left rear and the right tail light.  Getting to the approximate vicinity was essential.  Checking wires and connections in the rear, I finally found the short by pulling wires.  I pulled fairly hard on one of the green wires.  It broke where it was hidden between the frame and the body.  The insulation was gone, the copper wires were crushed.  It was obviously shorting against the frame.  Case closed. 
My project for the next couple of days will be redoing all the wiring the local RV store installed.  You live and learn.
Thanks again for everyone's help.
All the best,Tom Whitton26 foot updated GMCPaducah, KY
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Re: [GMCnet] Electrical Short found but it wasn't easy [message #315044 is a reply to message #315041] Thu, 23 March 2017 12:06 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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THOMAS R WHITTON wrote on Thu, 23 March 2017 11:35
...I pulled fairly hard on one of the green wires.  It broke where it was hidden between the frame and the body.  The insulation was gone, the copper wires were crushed. ...
If the gap between the body and frame are so tight they crush a wire, you desperately need new body pads.
Re: [GMCnet] Electrical Short found but it wasn't easy [message #315067 is a reply to message #315041] Fri, 24 March 2017 11:28 Go to previous messageGo to next message
roy1 is currently offline  roy1   United States
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Registered: July 2004
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A good reason some of us old mechanics don't trust other folks to work on their stuff. A short story 2 months ago my brother brought his Motorhome to a tire shop as he lost a tire on the road. He wouldn't let the shop use their impact on the wheel so he torqued it himself then he checked the air pressure with his own gage. There was only 20 lbs air in the tire? He surely would have lost both duals if he continued on his trip in his SOB coach.

Roy Keen Minden,NV 76 X Glenbrook
Re: [GMCnet] Electrical Short found but it wasn't easy [message #315069 is a reply to message #315067] Fri, 24 March 2017 13:20 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
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Location: Americus, GA
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Then there's the tire shop that I frequent: One day I noticed the
mechanic, whom I've seen there for the past 13 years, putting a LOT of air
in one of my tires. I asked him how much, "40 psi, just like it says on
the side of the tire -- That's what I ALWAYS do."

Need less to say a had a conversation with the owner.

Ken H.


On Fri, Mar 24, 2017 at 12:28 PM, roy keen wrote:

> A good reason some of us old mechanics don't trust other folks to work on
> their stuff. A short story 2 months ago my brother brought his Motorhome to
> a tire shop as he lost a tire on the road. He wouldn't let the shop use
> their impact on the wheel so he torqued it himself then he checked the air
> pressure with his own gage. There was only 20 lbs air in the tire? He
> surely would have lost both duals if he continued on his trip in his SOB
> coach.
> --
> Roy Keen
> Minden,NV
> 76 X Glenbrook
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Electrical Short found but it wasn't easy [message #315077 is a reply to message #315041] Fri, 24 March 2017 16:55 Go to previous messageGo to next message
kingd is currently offline  kingd   Canada
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Ken, did you really mean what you typed??
I don't understand ?????


DAVE KING lurker, wannabe Toronto, Ontario, Canada
Re: [GMCnet] Electrical Short found but it wasn't easy [message #315078 is a reply to message #315077] Fri, 24 March 2017 17:53 Go to previous messageGo to next message
Steve Jess is currently offline  Steve Jess   United States
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I think he meant that the mechanic was filling his car tire to the MAXIMUM pressure listed on the side of the tire, instead of the recommended pressure.


Steve Jess - Tucson, AZ
Mid-day/PM newscaster
Arizona Public Media


________________________________
From: Gmclist on behalf of Dave King
Sent: Friday, March 24, 2017 2:55 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Electrical Short found but it wasn't easy

Ken, did you really mean what you typed??
I don't understand ?????
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada

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Re: [GMCnet] Electrical Short found but it wasn't easy [message #315085 is a reply to message #315078] Fri, 24 March 2017 21:19 Go to previous messageGo to next message
GMCWiperMan is currently offline  GMCWiperMan   United States
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Steve's correct -- he always filled tires to the sidewall maximum.

Ken H.


On Mar 24, 2017 17:54, "Steve Jess" wrote:

I think he meant that the mechanic was filling his car tire to the MAXIMUM
pressure listed on the side of the tire, instead of the recommended
pressure.


Steve Jess - Tucson, AZ
Mid-day/PM newscaster
Arizona Public Media


________________________________
From: Gmclist on behalf of Dave King <
kingd@sympatico.ca>
Sent: Friday, March 24, 2017 2:55 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Electrical Short found but it wasn't easy

Ken, did you really mean what you typed??
I don't understand ?????
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada

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Re: [GMCnet] Electrical Short found but it wasn't easy [message #315093 is a reply to message #315085] Sat, 25 March 2017 04:28 Go to previous messageGo to next message
Handyman is currently offline  Handyman   Netherlands
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GMCWiperMan wrote on Sat, 25 March 2017 03:19
Steve's correct -- he always filled tires to the sidewall maximum.

Ken H.

Doing that brought me a while ago in trouble, the mechanic filled the front tires at 83 PSI ... driving around corners became a vibrating, ratteling adventure!
Going straight went to searching where do we go to now ....

But before I discovered that .... it took a while. Back to the requierd pressure, all was normal again, smooth driving.
To low pressure is dangerous, but to much can also be.

Daniel


Daniel Jacobs, NL-USA 1977 GMC Eleganza II, Rebuild 455 (2019) 3.55 FD. FiTech and (Modified) FCC, Electric Pump, insulated GasTanks, 100A Alternator, APC, McDash, Schräder Valves + extern Fills, Ceramic Film, TPMS, FlexSteel Seats
Re: [GMCnet] Electrical Short found but it wasn't easy [message #315098 is a reply to message #315093] Sat, 25 March 2017 10:53 Go to previous message
A Hamilto is currently offline  A Hamilto   United States
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Registered: April 2011
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Handyman wrote on Sat, 25 March 2017 04:28
GMCWiperMan wrote on Sat, 25 March 2017 03:19
Steve's correct -- he always filled tires to the sidewall maximum.

Ken H.

Doing that brought me a while ago in trouble, the mechanic filled the front tires at 83 PSI ... driving around corners became a vibrating, ratteling adventure!
Going straight went to searching where do we go to now ....

But before I discovered that .... it took a while. Back to the requierd pressure, all was normal again, smooth driving.
To low pressure is dangerous, but to much can also be.

Daniel
Keeping the thread drift going, overinflating also shrinks the amount of tire area in contact with the pavement, and that increases stopping distance. Not to mention causing more wear in the center of the tread, which means that part will get bald sooner, and you have to replace tires more often. Underinflating results in sidewall degradation, which can mean a blowout, plus more wear on the tread sides, which causes you to buy tires more often.

Keep your tires in the sweet spot for the load on them: http://gmcmotorhome.info/tires.html#PSI
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