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MrWhite
Joined: 09 May 2017 Posts: 105
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Posted: Mon Oct 23, 2017 12:56 pm Post subject: Positive earth radio in a Negtive earth car. |
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I have a car which was originally positive earth but has been changed to negative. Everything works, the Amp metre works in reverse but the radio and clock will be a positive earth and so don't work. Is there a way of getting them to work or do I need to replace them, which seems a shame as they are both fairly original to the car. I have to say I have managed to avoid the positive negative earth thing all my life so far, so I don't think I really understand Positive earth, my realisation of this came when someone mentioned fitting and ignition cut out (Old school security) and I then realised I wouldn't know how to do it. |
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Penman
Joined: 23 Nov 2007 Posts: 4755 Location: Swindon, Wilts.
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Posted: Mon Oct 23, 2017 1:11 pm Post subject: |
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Hi
With the clock and radio can't you just swap the wires over?
Put the positive wire to the negative terminal. _________________ Bristols should always come in pairs.
Any 2 from:-
Straight 6
V8 V10 |
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47Jag
Joined: 26 Jun 2008 Posts: 1480 Location: Bothwell, Scotland
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Posted: Mon Oct 23, 2017 2:34 pm Post subject: |
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Some older radios had a polarity switching plug which you moved to suit the car earth. Have a look for that. Otherwise it's easy enough to switch your car's polarity if it has a dynamo. It's a simple job to re-flash the field coils. If you reverse the leads as Penman suggests you will create a short circuit with the aerial wire. The clock I'm not sure about.
Art |
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47Jag
Joined: 26 Jun 2008 Posts: 1480 Location: Bothwell, Scotland
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Posted: Mon Oct 23, 2017 3:46 pm Post subject: |
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If the radio is in any way transistorised it will more than likely be for negative earth. Some older radios had a polarity switching plug which you moved to suit the car earth. Have a look for that. Otherwise it's easy enough to switch your car's polarity if it has a dynamo. It's a simple job to re-flash the field coils.
Art |
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peter scott
Joined: 18 Dec 2007 Posts: 7118 Location: Edinburgh
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Posted: Mon Oct 23, 2017 5:16 pm Post subject: |
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Penman wrote: | Hi
With the clock and radio can't you just swap the wires over?
Put the positive wire to the negative terminal. |
Unfortunately the case is normally the earth connection in radios.
It's very easy to change your car's earthing to suit the radio. The only minor complication is that you need to swap the connectors on the battery leads if you have circular posts as they are slightly different diameters.
Peter _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon |
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DM
Joined: 21 Dec 2008 Posts: 212 Location: North Cornwall
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Bitumen Boy
Joined: 26 Jan 2012 Posts: 1735 Location: Above the snow line in old Monmouthshire
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Posted: Mon Oct 23, 2017 8:00 pm Post subject: |
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I'd be surprised if a radio old enough to be positive earth would still work satisfactorily nowadays. TBH I'd think it likely to be ripe for replacement or conversion to modern internals. |
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ukdave2002
Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire
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Posted: Mon Oct 23, 2017 9:09 pm Post subject: |
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Unless there is any reason to stay as negative earth.; simply convert it back
Dave |
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lowdrag
Joined: 10 Apr 2009 Posts: 1585 Location: Le Mans
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Posted: Tue Oct 24, 2017 8:07 am Post subject: |
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Bitumen Boy wrote: | I'd be surprised if a radio old enough to be positive earth would still work satisfactorily nowadays. TBH I'd think it likely to be ripe for replacement or conversion to modern internals. |
I had my Radiomobile converted to modern FM internals by Tadpole radios. A total waste of money and it is never used. I see that the Becker Mexico modern version is back in production but last time it was £700 and now is over £3,000! Be good to have inbuilt GPS, Bluetooth and USB and iPlayer features but not at that cost. A total rip-off.
http://www.ebay.co.uk/itm/BECKER-MEXICO-RETRO-Vintage-GPS-BT-Navigation-Radio-Classic-Car-7942-7948-NEW-/201394591783 |
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Riley Blue
Joined: 18 Jun 2008 Posts: 1750 Location: Derbyshire
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Posted: Tue Oct 24, 2017 9:32 am Post subject: |
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lowdrag wrote: | Bitumen Boy wrote: | I'd be surprised if a radio old enough to be positive earth would still work satisfactorily nowadays. TBH I'd think it likely to be ripe for replacement or conversion to modern internals. |
I had my Radiomobile converted to modern FM internals by Tadpole radios. A total waste of money and it is never used. I see that the Becker Mexico modern version is back in production but last time it was £700 and now is over £3,000! Be good to have inbuilt GPS, Bluetooth and USB and iPlayer features but not at that cost. A total rip-off.
http://www.ebay.co.uk/itm/BECKER-MEXICO-RETRO-Vintage-GPS-BT-Navigation-Radio-Classic-Car-7942-7948-NEW-/201394591783 |
Good grief - that's more than I paid for my Riley!!
I never listen to the radio or music when I'm driving, I'm not even sure how to load the six disc changer in the Audi that I've owned for several years and radio in the Riley just seems pointless. _________________ David
1963 Riley 1.5
1965 Riley 1.5 |
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Paul fairall
Joined: 17 Nov 2016 Posts: 429 Location: North west Kent
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Posted: Tue Oct 24, 2017 12:56 pm Post subject: |
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Me neither, if I want to listen to music I have a dedicated music room in the garden. Listening in a car with tyre noise etc is not my idea of enjoyment. _________________ 1957 ford popular |
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Bitumen Boy
Joined: 26 Jan 2012 Posts: 1735 Location: Above the snow line in old Monmouthshire
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Posted: Tue Oct 24, 2017 3:04 pm Post subject: |
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Paul fairall wrote: | Me neither, if I want to listen to music I have a dedicated music room in the garden... |
Nice if you have the time. For many people they only time they get to listen unmolested to their own choice of music is the otherwise wasted time spent driving to or from somewhere they don't particularly want to be in the first place. |
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Paul fairall
Joined: 17 Nov 2016 Posts: 429 Location: North west Kent
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Posted: Tue Oct 24, 2017 6:35 pm Post subject: |
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For many years I sat in traffic jams going into London, I guess those that still endure that have time for listening then. Everyone should make time for relaxing or doing what they love otherwise what is the point of living. _________________ 1957 ford popular |
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kevin2306
Joined: 01 Jul 2013 Posts: 1359 Location: nr Llangollen, north wales
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Posted: Tue Oct 24, 2017 8:08 pm Post subject: |
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When I bought the restored Motorola 828 for my singer, I had a lead fitted so I can use it with my iPod. Love music when driving,more so in my modern.
Kevin |
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MrWhite
Joined: 09 May 2017 Posts: 105
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Posted: Wed Oct 25, 2017 10:14 pm Post subject: |
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Thanks for your replies, lots of ideas, so that's good. I am not sure what happened with the car as we didn't have it for a while and it was positive earth when we had it before but now negative earth and the advive we were given was to leave it as it is. I should maybe have asked more questions about this but at the time I just thought Negative earth is more what I am used to, so it should make things easier, less likelyhood of connecting anything up the wrong way. I will have a look at the items and see if there are any switches, that almost seems too easy. I did read about "Flashing" but I have no idea how you do this (electrically of course) or what it actually means, so I wouldn't mind an explination of what to do or a pointer in the right direction. I think I probably still prefer to keep the car Negative earth, the more modern radio or the converter box are great ideas but I think just a wee bit on the expensive side. I doubt I will listen to the radio much but I do like music in the car (modern car usually), mainly I just don't like having things that don't work |
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