Bad 4-way rotary switch?

[fender3x]

I am working on a guitar with dual humbuckers. It has a four way switch to go between humbucking and single coil modes. Setting 1 is HH, setting 2 is SH, setting 3 is HS and setting four is SS.

All the settings work fine...sort of. Going from 1 to 4 everything works perfectly. However when I go from 4 to 1, on 1 the neck pickup cuts out. If I tap the knob, it comes back in. This does not happen at all on setting 3 which is also neck humbucking, or on settings 3 or 4 which are neck single-coil.

After a bit more fiddling with it, I noticed that when the knob is on setting 1 if I try to turn it a little counter-clockwise it cuts out. But if I turn it clockwise a little without clicking it, the pup comes back in. This is very reliable. In setting one jiggling to the left turns the pup off. Jiggling to the right turns it back on.

All settings work fine with the bridge pickup. This is a four-way, three gang switch. I am using gang 1 for the neck pickup, and gang 2 for the bridge pickup. I did not use gang 3.

I think the problem may be a wiggly contact on setting 1, gang 1. Gang 2 seems fine. Assuming gang three is OK, I am thinking I could jump the common lug from gang 1 to gang 3, and jump the the lugs for setting 1 on gang 1 to the setting 1 lug on gang 3. Assuming that gang 3 works properly, this should solve the problem, right?

Can't think of anything else to do other than to replace the switch. Since it was a pain to wire up, I'd rather not do that if I don't have to...

[JimC]

So duplicate gang 1 to gang 3. Got to be worth trying.

[Simon Barden]

You may possibly have damaged it by getting it too hot. Or it may just be a bad switch. I'd be very tempted to replace it and also duplicate as many contacts as you can when soldering the new switch.

[fender3x]

Bit of experimenting this morning... I tried the work around, and it seemed to work. Since everything on gang 1 was working except position 1, I just jumped common G1 to common G3 and jumped the lead going to G1P1 to G3P1. Did not rewire everything to G3.

Once I had done that the the neck pickup dropped out completely. Everything looked good on the switch...so I decided it must be their was a break in one of the pup leads, or a bad solder connection. Re-tinned and re-soldered the wire, and tested for continuity...all good.

This is when I noticed that the ground wire for the pup had come loose. Re-soldered that and everything went deadly quite...no hum...nothing. I thought I had killed it.

But it turns out that once properly grounded, the humbuckers just seem to be quiet. Tap tests worked on both pickups in all positions of the pickup selector switch as well as the 4-way. I tried to jiggle it in the ways that had been disconnecting the pup, the connection appears now to be solid.

So was it the switch? Or was it the faulty ground? Or was it the pup wire that may have had a cold solder problem? I am no longer sure.

However, I am grateful for the advice! Not much to loose trying it, as JimC says...and because if it failed once it can fail again as Simon implied...I am ordering another 4 way, so I'll have it on hand if the switch turns out to be more defective than it appears.

Gracias señores!