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Grounds [message #295326] Tue, 09 February 2016 22:51 Go to next message
Hal StClair   United States
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
Senior Member
I've been struggling with a non operational cruise control ever since the diesel swap. It's about driven me nuts as everything seemed to be wired correctly but still no joy. I did manage to get it to engage once but I couldn't repeat the feat and have been àt a loss for the last month. After going over everything for the twentieth time I found a ground with about 3 ohms of resistance. Not enough to kill the function of the DRAC (digital ratio adaptor) as the trans shifted great or to set a trouble code but apparently enough to disrupt the cruise signal. Testing the ground with a voltmeter or test light checked out good but the PCM is only working on a five volt signal there and 3 ohms killed it. It's really ironic that a ground issue was the problem as my advice is normally to be sure and first check your GROUNDS. Too bad I wasn't a little more diligent and taken my own advice, it would have saved me countless hours of frustration.
Happy, happy now though.☺ Hal


"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane." 1977 Royale 101348, 1977 Royale 101586, Diesel powered, 1974 Eagle Bus 45',w/slideout, Rio Rancho, NM
Re: [GMCnet] Grounds [message #295328 is a reply to message #295326] Wed, 10 February 2016 00:06 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Hal,
You can relate to how frustrating it is for our shop as these small thing
constantly slow our production in our shop.
Since we are an authorized installer and dealer for for Blue Ox, we get in
40' pushers to wire up for towing, which tie up space and we need to get
them out quickly.
Unlike the GMC, we need to get wire diagrams from the manufactures and
there are sometimes over two hour wait before we can get help.

On Tue, Feb 9, 2016 at 8:51 PM, Hal StClair
wrote:

> I've been struggling with a non operational cruise control ever since the
> diesel swap. It's about driven me nuts as everything seemed to be wired
> correctly but still no joy. I did manage to get it to engage once but I
> couldn't repeat the feat and have been àt a loss for the last month. After
> going over everything for the twentieth time I found a ground with about 3
> ohms of resistance. Not enough to kill the function of the DRAC (digital
> ratio adaptor) as the trans shifted great or to set a trouble code but
> apparently enough to disrupt the cruise signal. Testing the ground with a
> voltmeter or test light checked out good but the PCM is only working on a
> five volt signal there and 3 ohms killed it. It's really ironic that a
> ground issue was the problem as my advice is normally to be sure and first
> check your GROUNDS. Too bad I wasn't a little more diligent and taken my
> own advice, it would have saved me countless hours of frustration.
> Happy, happy now though.☺ Hal
> --
> 1977 Royale 101348,
>
> 1977 Royale 101586,
>
> 1974 Eagle Bus 45',w/slideout
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Grounds [message #295330 is a reply to message #295328] Wed, 10 February 2016 03:41 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
Read here
http://gmcmotorhome.info/speed.html#drop

Erf

On Tuesday, February 9, 2016, Jim Kanomata wrote:

> Hal,
> You can relate to how frustrating it is for our shop as these small thing
> constantly slow our production in our shop.
> Since we are an authorized installer and dealer for for Blue Ox, we get in
> 40' pushers to wire up for towing, which tie up space and we need to get
> them out quickly.
> Unlike the GMC, we need to get wire diagrams from the manufactures and
> there are sometimes over two hour wait before we can get help.
>
> On Tue, Feb 9, 2016 at 8:51 PM, Hal StClair >
> wrote:
>
>> I've been struggling with a non operational cruise control ever since the
>> diesel swap. It's about driven me nuts as everything seemed to be wired
>> correctly but still no joy. I did manage to get it to engage once but I
>> couldn't repeat the feat and have been àt a loss for the last month.
> After
>> going over everything for the twentieth time I found a ground with about
> 3
>> ohms of resistance. Not enough to kill the function of the DRAC (digital
>> ratio adaptor) as the trans shifted great or to set a trouble code but
>> apparently enough to disrupt the cruise signal. Testing the ground with a
>> voltmeter or test light checked out good but the PCM is only working on a
>> five volt signal there and 3 ohms killed it. It's really ironic that a
>> ground issue was the problem as my advice is normally to be sure and
> first
>> check your GROUNDS. Too bad I wasn't a little more diligent and taken my
>> own advice, it would have saved me countless hours of frustration.
>> Happy, happy now though.☺ Hal
>> --
>> 1977 Royale 101348,
>>
>> 1977 Royale 101586,
>>
>> 1974 Eagle Bus 45',w/slideout
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Fremont,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>


--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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Re: [GMCnet] Grounds [message #295338 is a reply to message #295330] Wed, 10 February 2016 09:53 Go to previous messageGo to next message
Hal StClair   United States
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
Senior Member
I wish it would have been that simple Gene. I don't have led tail/directional lights but common fix for them would have been a load resistor. Using the dump switch looks like an easier approach to that problem though, thanks for the link. I don't know how you're able to pull up all the helpful information all the time, but thank you for your efforts.
Hal


"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane." 1977 Royale 101348, 1977 Royale 101586, Diesel powered, 1974 Eagle Bus 45',w/slideout, Rio Rancho, NM
Re: [GMCnet] Grounds [message #295370 is a reply to message #295338] Thu, 11 February 2016 00:57 Go to previous message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
I did that wiring change to my Rostra when I installed it years ago. I do not have LED brake lights but it is a more reliable way to wire up the Rostra CC.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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