Positive earth classic car

[crankedup]

I would like to keep the positive earth system on my classic car but need to use my sat nav and other items. Has anybody any links to a good auto electrician who can fit a negative earth
adapter (ciggi lighter ?) whilst retaining my positive earth system?
Also I need a audio bleeper to work for my soon to be installed tow bar, I cannot find a supplier of positive earth bleepers?
East Anglia region preferred.
Thank you.

Edited by crankedup on Wednesday 21st March 11:32

[jkh112]

I may be being a bit dense and opening myself up for some ridicule but I am going to post anyway.

If the lighter socket you want to fit has positive and negative supply wires then do you not just connect the positive wire to the chassis and the negative side back to the battery? The items you then plug into the socket don’t care how the positive and negative sides are connected back to the battery.
(Obviously this doesn’t apply to items such as alternators, starter motors etc which are bolted to the chassis or to radios where the chassis is their earth.)

[crankedup]

I know SFA about auto electrics, in the absense of any poster contradicting your advise I will go with that. Thanks for posting.

[jkh112]

I know not much more than SFA about it. If you do take my advice then please do not try anything expensive in the socket the first time you use it.

[PositronicRay]

Just fit something like this somewhere unobtrusive,

https://www.amazon.co.uk/Waterproof-Cigarette-Ligh...

[Riley Blue]

Here' s some advice from someone who has done it:

http://www.mossmotoring.com/negative-ground-lighte...

[davepoth]

crankedup said:

I would like to keep the positive earth system on my classic car but need to use my sat nav and other items. Has anybody any links to a good auto electrician who can fit a negative earth
adapter (ciggi lighter ?) whilst retaining my positive earth system?
Also I need a audio bleeper to work for my soon to be installed tow bar, I cannot find a supplier of positive earth bleepers?
East Anglia region preferred.
Thank you.

Edited by crankedup on Wednesday 21st March 11:32

Depending on the car, a negative earth conversion is probably much easier (and less intrusive) than doing what you want to do. In many cases it will involve turning the battery 180 degrees and swapping the wires on the coil, rev counter, ammeter and dynamo (although this would be a good time to bolt in an alternator).

In most cases this is completely reversible if you ever wanted to revert to positive earth, and would allow you to use modern accessories.

[David Beer]

The only problem would be anything that has an earth, ie aerial. A head unit does not see it’s a positive earth, until you connect an aerial that is earthed. There are ways around that. So providing the chassis of the radio is not directly bolted to the earth of the car, no problem. Same for any device you need . I have been in car audio for 25 years,see profile.

[Fastpedeller]

jkh112 said:

I may be being a bit dense and opening myself up for some ridicule but I am going to post anyway.

If the lighter socket you want to fit has positive and negative supply wires then do you not just connect the positive wire to the chassis and the negative side back to the battery? The items you then plug into the socket don’t care how the positive and negative sides are connected back to the battery.
(Obviously this doesn’t apply to items such as alternators, starter motors etc which are bolted to the chassis or to radios where the chassis is their earth.)

You beat me to it..... by several days

[crankedup]

Thanks chaps for the advise and links.

Can I push it further, I am about to tow my old caravan will the wiring on the caravan be OK with the new tow bar electrics being positive earth?