I have some all lipstick Jerry Jones guitars (12-string, Guitarlin, Longhorn Bass6 and guit/bari double neck).
I'm not sure if I like that all of them are wired in series. So my question is: Is it possible to rewire them to be in parallel instead? Especially the 12-string, which features three pickups. It would be nice to hear that one on parallel in the 2 and 4 position. It sound very hard now, to my ears.
Yes, it is certainly possible to rewire for parallel. Before we can tell you exactly how to do that, we'll need to know how each of these is wired. Probably best to pick one to do first.
Since most guitars are wired in parallel, you can probably find a wiring diagram from some other guitar to use. For example, if your three-pickup guitar has a regular Strat-type 5-way switch, you can use any standard Strat wiring diagram.
While you can certainly permanently rewire these to parallel, you may want to consider the possibility of keeping some or all of the series options by using a switch (or switches) to switch between series and parallel, thereby letting you keep both options available.