Practically Classics Forum

I have a Rover P6 1964 with positive earth. Short of reversing the polarity is it safe to use SatNav, tyre inflator through the cigar socket ? Thes are designed I assume for modern negative earth and I don't want to damage them or blow fuses in my Rover.
Roy Payne

Quick answer is no!
but Tyre inflater could be ok, but Sat Nav is no

I'd say yes to the SatNav, so long as you a) connect the correct polarity wire to the feed to the device and b) make sure that no metal par of the device can possibly come into contact with any metal part of the car - if it does, it will blow the cigar lighter fuse as this will make the circuit a dedad short. However, the casing of SatNavs is mainly plastic, and where you would want to mount it it mainly plastic and glass, so you'd probably get away with it.

The same goes for the tyre inflator but might be a bit more risky in terms of it never coming into contact with the body of the car.

Or you could convert the car to Neg earth which is quite easy!

Cheers

Yep, switch the wires around on the Sat nav. As long as it gets the + on it's + connector, it couldn't care less whether the + came from your chassis or from your battery/alternator.

You could add a second cigar socket that is wired the negative earth way and is isolated from the car's body and seperately fused. That way you can use any modern accessory you want - SatNav, iPod, Phone Chargers etc.

The new socket could be hidden under the dash so it doesn't alter the look of your dash.

Malpin/Maplin or whatever you call it electronic stores should have the easy to mount plastic cased type like this: Cheers,
Brett.

Many thanks guys or gals. I have now conveerted car to negative earth for safety
Roy