Fender MIJ P-Lyte - PUPS, Pre-Amp and Wiring

[Mentor Bass]

Dear All, have read several posts on here, dating back centuries...
Not quite found what I need.
I recently acquired a 1991, Tobacco-Burst P-Lyte, verrrry nice. Sounds like it should, feels great, weighs not much.
But... it seems to eat batteries.... and currently has a touchy input jack. Works for days without an issue, then decides to crackle crackle.
Anyway, long story short, thought I would pull the back cover off, pull out the electronics and wire it up fresh - and that is where we strike problems.
I haven't been able to find any wiring diagram of the same thing. It has a small pre-amp, P-J Pups and 4 knobs, Vol-Blend-Bass-Treble and a 9v battery.
If anyone out there has the same and could take the time to draw out the way it should be wired I would be very thankful.
I would also be VERY interested in any one else's experience on the P-Lyte Bass, in changing it to fully passive, or alternative PUP/Pre-Amp combinations.
Thanks to all - cheers

 

[Crater]

I haven't been able to find any wiring diagram of the same thing. It has a small pre-amp, P-J Pups and 4 knobs, Vol-Blend-Bass-Treble and a 9v battery.

That is actually a pretty common setup for active basses. Most likely it is wired like this:

The bass & treble controls are connected directly to the preamp and aren't shown in this schematic. Volume pot should be 25 kΩ or 50 kΩ.

"Eating batteries" is typically caused by a mis-wired output jack, or neglecting to unplug the lead from the bass when you're not playing, or it could be a short between the negative battery lead and ground. Crackling can be caused by a worn-out output jack, 'barrel' type jacks in particular are known for failing this way, when they do it's time to replace them. Removing the electronics from your bass was probably unnecessary and you've made some extra work for yourself.

 

[Mentor Bass]

Thanks Crater, Will have a look at it today and see if it follows that pattern. Just to confirm, I haven't actually pulled anything out yet, just pulled the cover off, took a look and thought "need a diagram"
I learnt years ago that the lead needs to be out when not in use, so that isn't the problem. Am leaning towards either a mis-wired or worn output jack.

 

[Mentor Bass]

Did a thorough check. Seems to be wired s per your diagram, hard to tell with the ribbons between the pre-amps. Another problem I forgot to mention is that compared to all (even passive) other Basses, it is very quiet. I have a Yamaha Mixing desk, and most basses are set around the 3 mark, whereas I need to push this to 9 to get similar volume, which leads to a kind of pfft sound too. Anyway, am starting to think that part of the system is dud. Started looking around for a similar harness, VOL/Blend/Bass/Treble but can't seem to find one. Lots of Vol/Vol/Tone out there... may have to leave one knob as a 'nothing'.

 

[Crater]

The blend control typically isn't included with a preamp, although some EMGs can be ordered with one. Most preamps have a single input, there are a few with buffered blending (I know Cort has one) but those are the exception. Almost any 2-band (bass/treble) preamp should be able to work.