Yep, I started selling cb radios and business band stuff in 1972.  A few 
farm tractors also had reverse polarity.  One of the strangest things I 
hooked up using a little converter box and isolating stuff was I put a 
12 v cb radio in my old 1947 ford which was 6 v positive ground.
73
Butch Bussen
wa0vjr
open Node 3148
Las Vegas


On Fri, 
3 Oct 2008, Colin McDonald wrote:

> not sure if you were installing radios in the 70's, but i think it was
> either freightliner or peterbuilt that had reversed polarity as a standard
> in their tractors for years.
> It kept repare shops in business for quite a while until someone had the
> good sence to make the polarity and wiring scheme more standard.
> Now they put in 22 dollar relays to save 30 sent parts in electronics in
> most vehicles.
> 73
> Colin, V A6BKX
> ----- Original Message -----
> From: "Butch Bussen" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, October 03, 2008 9:39 AM
> Subject: Re: correctly wiring power cable for TW1
>
>
>>
>> Speaking of smoke, I blew up a brand new cb radio once.  I sold radios and
>> the local fire district wanted me to install a radio in their fire truck.
>> Was an old military duce and a half.  I hooked up the radio and turned it
>> on and the smoke roled!!!.  I grabbed my volt meter to check polarity.
>> Polarity was right, but the thing ran on 24 volts.  That cost me a new
>> radio and I found the batteries under the seat and hooked to 12 v.
>> 73
>> Butch Bussen
>> wa0vjr
>> open Node 3148
>> Las Vegas
>>
>>
>> --
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> 8:18 AM
>>
>>
>
>