Middle position volume too low after pickup swap

[Orcane]

Hey there,

I let a local shop swap the SH-4 bridge pickup for a SH-5 and the volume regulation for the middle position is broken ever since, whereas the bridge and neck pickup work fine.
The problem is that whenever both pickups are on about the same volume level the middle position is about half as loud as the pickup positions and sounds a bit like there's a wah on it. When increasing or decreasing the volume of one pickup the middle position is finally as loud as the pickups, however sounds pretty much like the pickup that was affected by the volume change.

As the shop stated the electronics weren't changed when swapping the pickup.
So we're wondering if there's anything special that needs to be considered or checked. I wouldn't like to replace the electronics unless it is necessary, so I'd appreciate it if you can give me hints on what's wrong.

The guitar is a ESP LTD EC-401VF with a SH-1 in the neck position (stock). As stated the stock bridge pickup was the SH-4 and was replaced with a SH-5. There were no other modifications on the electronics so far.

Thanks in advance!

 

[allbutromeo]

Re: Middle position volume too low after pickup swap

Sounds like the pickup was wired out of phase.

 

[beaubrummels]

Re: Middle position volume too low after pickup swap

+1 if rolling one of the volumes improves it, you've got a phase problem

 

[uOpt]

Re: Middle position volume too low after pickup swap

+1. It's out of phase.

 

[Orcane]

Re: Middle position volume too low after pickup swap

Thanks so far!

Can anyone explain how to fix the phase?
When googling I've found a couple of solutions, like reversing the magnet in the pickup or changing wires, however I don't really know how to start. If possible I'd like to avoid having the shop tech fiddling with the magnet.The neck pickup is covered (and waxed I assume), the bridge is not.

 

[jeremy]

Re: Middle position volume too low after pickup swap

flip the black and green wires on the bridge pup and you should be good

 

[Orcane]

Re: Middle position volume too low after pickup swap

Thanks for the fast reply. I told the tech about the wires and hope that he'll attempt to fix it that way.