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#95062 03/13/2006 1:31 PM | Joined: Dec 2005 Posts: 7 Junior Member | | Junior Member Joined: Dec 2005 Posts: 7 | 55 GMC 12volt Ign coil is marked that it doesn't need a resistor. But I think that you would still need to install a resistor to the original gas guage. Am I right or wrong ?
Phxamigo
Phxamigo
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#95063 03/13/2006 1:59 PM | Joined: Sep 2003 Posts: 343 Member | | Member Joined: Sep 2003 Posts: 343 | If your truck was originally a 6 volt truck and you still have your original 6 volt gauge, then you will need the resistor for the gauge. The reason 12V coil does not need a resistor is because the resistor is built into it.
Jim
1954 GMC 1/2-ton Longbed
1971 Pontiac LeMans Sport
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#95064 03/16/2006 10:17 PM | Joined: Dec 2005 Posts: 324 Member | | Member Joined: Dec 2005 Posts: 324 | When did GMC change over to 12 volt system? i thought it was 55, but could be wrong.
"It ain't a truck if you can't hose out the cab."
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#95065 03/16/2006 10:44 PM | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | amigo - the ignition resistor required for a coil has nothing to do with the dropping resistor required for using a 6volt gauge on 12volts, so yes, you still need that as Jim sez
Chester, I think GMC was a year behind Chev and used 6volt in 55, 12volt in 56
Bill | | |
#95066 03/17/2006 4:39 PM | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | I am not sure about this and hope that someone who is certain will correct me. American GMCs used 6v positive ground on 6 cylinder engines through 1955-2nd series and used 12v negative ground on V-8s on 1955-2nd series trucks (as standard equipment - some models had optional voltages). | | |
#95067 03/19/2006 12:25 AM | Joined: Dec 2005 Posts: 324 Member | | Member Joined: Dec 2005 Posts: 324 | I am not in a place i can check the referances. but my 39 chevy 6 has 6 volt neg ground.
"It ain't a truck if you can't hose out the cab."
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#95068 03/19/2006 12:34 AM | Joined: Feb 2002 Posts: 12,029 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Feb 2002 Posts: 12,029 | yes Chester, but GMC used positive ground for years back then
Bill | | |
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