Replace car cigarette lighter adaptor! Help

[ih]

Hi need to help retired neighbour on replacement of the adaptor which is linked to tyre inflator
While pulling out from the socket it broke worst is both wires are black to replace
I need to know which one on is positive & negative is there anybody out there
Who can identify from the photo??? If not I do have multi meter but will need
Idiots guide to use & identify thanking in advance for help/advise
Regards
Ih

 

[freddiemercurystwin]

 

[ih]

@freddiemercurystwin
Thank you for your help my problem is I need to identify positive & negative in my black wires! Unless I have misunderstood
You & you mean positive on the black wire is wire soldered to the metal and negative is the clip wire? Clarification will be
Appreciated thanks

 

[freddiemercurystwin]

 

[ih]

@freddiemercurystwin
Many thanks for clarification you are top man this inflator is also handy as neighbour hood kids come with
Bycles for pressure