Positive Ground Radio Trouble

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=124662
Printed Date: May 20, 2024 at 9:18 PM

Topic: Positive Ground Radio Trouble

Posted By: reaper88
Subject: Positive Ground Radio Trouble
Date Posted: November 25, 2010 at 7:54 PM

okay so im trying to install a radio on a Positive Ground vehicle.

im having problems getting it work when i go directly to the battery.

my idea is to use a couple relays to convert the Positive ground to a Negative ground and convert the power to Positive.

Can it be done and if so please, please i really need an explinatinon.

Thanks so much!

Replies:

Posted By: i am an idiot
Date Posted: November 25, 2010 at 8:17 PM

You do not need any relays. You do need to know that the metal case of the radio and the shield conductor of the antenna wire are connected to the black wire of the radio. You can not let the chassis of the radio, or the mounting portion of the antenna contact the chassis of the vehicle. You will probably need to put a switch between the chassis of the vehicle and the red wire of the radio. The yellow wire of the radio can be connected directly to the chassis of the vehicle. The ground wire of the radio needs to be run to the negative terminal of the battery.

Posted By: howie ll
Date Posted: November 26, 2010 at 3:05 AM

Oh the memories of changing polarity on pre 1970 vehicles! Providing this is one of those and has a dynamo rather than alternator and the rev counter if present is mechanical (old MGB, etc.) it's easier to take that route.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Posted By: t&t tech
Date Posted: November 29, 2010 at 5:06 PM

Positive ground? Do you mean the body of the vehicle is positive? @ Howard and IAAI

Posted By: howie ll
Date Posted: November 29, 2010 at 5:33 PM

Yes, many countries mostly the UK used pos ground until the 1960s. They changed to neg with the advent of alternators instead of generators or dynamos and the fact that for some reason there was less corrosion with neg ground.
Ford UK, Vauxhall (GM) and Standard Triumph, Jag Rover and Rolls Royce changed over by 1966. Austin/Morris Riley, Wolsely and MG, 1970.
Early Lotus Elans with pos ground wiring were great fun.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.