4AD Electrical - Positive or Negative

[tufsinger]

Howdy all!

Just acquired a '53 4AD Roadster (it's in transport so anxious to get it and take it for a drive). I'm having trouble finding info on the electrical system. Based on what I've seen in the forums and been able to read online it looks like the 4AD's are definitely 12v systems, but there seems to be mixed information on whether they are positive or negative ground. The motor-trader document appears to show a positive ground system. Can anyone confirm?

Many thanks and looking forward to being part of the family.

[Mark Thompson]

Definitely, positive ground!

Mark Thompson

[mikeyr]

absolutely positive that its positive ground

The confusion might be from the 1930's when Singer's were negative ground and I don't know when they switched to positive but the 4AD's are positive.

[tufsinger]

Fantastic. As I suspected. Will be a little tough putting a radio in it. May consider a negative ground conversion though I believe the vehicle has been restored 100% original (based on what the seller told me) and if that's the case I may need to figure out alternatives.

It was loaded on the truck today and set to arrive Saturday or Monday. Will let you all know and post picts.

Thank you!

[Mark Thompson]

No need for a radio. You will be singing a happy tune whenever you drive it!

Mark Thompson

[kabu]

Hi,

I agree with Mark; no need for a radio

However, if you do want one, I'd leave the car electrics and polarity original and acquire a radio that is compatible with positive ground (I believe they are available in the "retro" ranges of some manufacturers). Another option is using a voltage converter approach like described for instance here http://mgaguru.com/mgtech/electric/et207.htm


Regards,
Pekka