Fender Precision Plus. E and A strings cut out on P-Bass p/u in parallel. Normal?

Hi All,
I recently obtained a 1990 Fender Precision Plus. P/J pickups, 3-way selector switch, series parallel switch, 1 volume, 1 TBX tone control. It's a quirky bass in several ways (especially compared to my other. more traditional, P-Basses). It's very cool and a keeper. There's just one thing I'm confused about and haven't come across this issue in my searches ...

Although I will likely always have the bass in series mode for a fuller / beefier tone, the parallel mode is not bad - not as ballsy, but still sounds like a bass guitar. More focused. And I don't notice the big volume drops that others have described when in parallel mode with both pickups activated. With both the P&J pickups on, both series and parallel work as they should. Same thing with the J pickup solo'd.

However, if I just have the P pickup on and switch to series, the E and A strings cut out. As first I thought this was normal since the P pickup is split. However, in searching for info to confirm this, I'm not finding anyone else who has had half the pickup cut out completely in parallel.

Basically I'm wondering if this is normal or not. If not, does it make sense that both P coils would work in parallel in series with the J pickup?

If pics of the wiring would help with the answer, I'm happy to look under the pickguard and take pics of the wiring to post here.

Thanks in advance for any info!

Cheers!

1990 Fender Precision Plus by CPplaysBASS posted Jul 29, 2016 at 11:01 AM

 

Thanks LTB! I was reluctant to take out the actual pickup as I tend to create more problems whenever I'm near my basses while holding a screwdriver!

From what I can tell, there is a green and orange wire connecting the two PBass coils. The rest if the wiring is the mess seen in the pics. Left to right is 3-way selector, volume, series / parallel switch, and the TBX tone.

I also found what I think is the proper wiring diagram. I'll attempt to follow the diagram compared to what I see with my bass.

Cheers!

 

Pulled out the pickup. Pic attached.