Jazzmaster shenanigans

[galaxy08]

A funny thing occurred yesterday when I changed the pickguard on my Fender Classic 60s Jazzmaster. Everything went smoothly, but when I plugged it back it to give it a whirl, the toggle switch worked fine for the bridge pickup position, but the middle and neck positions seems to be activating the rhythm position, while the rhythm switch seemed to be activating the neck or middle pickup. What the heck??!! I barely moved the wires while I made the pickguard swap, but something obviously got knocked out of whack. This was the first time I'd ever changed a pickguard, so I'm sure it's ignorance on my end, but I have no idea what I could've done, and don't want to futz with it again until I have a better sense of what the problem likely is and how to fix it.

Any insight, advice or guidance would be much appreciated!

[AztecGold]

Are there bare wires anywhere, wires that are touching that weren't before, solder joints that are touching on the switches (especially that slider switch, or things that are getting grounded or shorted in a way that they weren't before? Sometimes the wiring is a bit sloppy in those MIMs and unless you somehow damaged a switch (sounds unlikely) it may be worth taking it off again, making sure wiring is all routed as it should be, and putting it back together.

[smjenkins]

Whenever I hit an issue like this changing a pickguard, it's always been that I ended getting a wire out of the route path it was in and stuck / smashed somewhere it shouldn't be and it grounds something out as galaxy08 suggested.

To address this, remove all the screws and nuts to free up the pickguard and then lift everything up to make sure nothing is getting smashed under the guard. Then plug the output jack into an amp and use a screwdriver (or anything metal) to drag across the pickups to make sure they work. You can use this method to test the pu switching, volume and tone knobs too. If everything works fine when unscrewed and lifted, carefully make sure that all the wires are where they should be under the guard when you put it back together. This can be tricky to make sure everything sits flush under the guard without extra pressure.

Once you have everything sitting in the right place, test all the pickups and switches again with the screwdriver. If it still works, you can then start screwing everything back down. I'd check that everything is still working with the screwdriver after the first few screws and again after your finished.

Best of luck with debugging

[galaxy08]

Thanks for the replies! I’ll remove the pickguard and give it another go. Thanks for the helpful info!