Telecaster – pots shorting on control plate

545454

Swapped out a pickup last night (neck humbucker, 4 wire with middle 2 taped off) – nothing complicated and have done it plenty of times before. However wasn’t getting any signal from either pickup.

Connections all look fine and was getting continuity between pickup > switch > volume > output. So wondered if I’d damaged a pot – unscrewed them to try swapping them and the signal started coming through fine. Turns out the signal is shorting when the pot is attached to the control plate (either pot shaft or upper edge when I tighten the washer).

Can anyone smarter than me suggest what might have gone wrong?? I can’t see anything that looks out of place and it’s really frustrating. (Sorry didn’t take any pics). Cavities have copper shielding but problem exists when plate is outside the body. Same switch, same pots, same everything except for the pickup leads, but it’s possible I’ve damaged something when squashing all the wires back inside. I subsequently swapped the pots, but same problem. Am I just crap at soldering?

ICBM

Hard to say without a pic, but firstly, if you’re having to ‘squash’ the wires into the cavity then you have far too much excess wire. A Tele circuit is quite neat and should fit very easily.

If there’s a short between the pot and the plate which kills the output then either the pot casing or the plate is shorted to hot. Where does the ground wire from the jack go to - volume or tone pot casing? If it goes to the volume then the short is to the plate somewhere, if it goes to the tone then the problem is the pot.

545454

Thanks @ICBM - jack ground is going to volume pot, so will have a look at the plate tonight. Might just start from scratch and trim the excess pickup wire to tidy things up - it is a bit of a rat's nest at the mo...

Funkfingers

545454 said:

I subsequently swapped the pots but same problem.

Have you changed the selector switch? 

Does the signal pass when the selector switch is fastened to the control plate but the pots are not?

What sort of selector switch are you using? Sprung CRL, unsprung, Oak Grigsby, basic (eight contacts in line) PCB, complex PCB (Schaller, OTAX, Freeway et cetera). Some of these designs include a grounding tag on the PCB side. 

This is the sort of information that would be conveyed by two or three clear photographs.

545454

It's still the same selector switch (basic 8 in-line type), and yes the signal passes with the switch fastened but pots loose.
Was getting so fed up with it I just put some electrical tape around the mounting holes and put it all back together. If not luck after a rewire later I'll take some close up pics 

ICBM

I think it's more likely to be at the tone control. If it works with the volume pot off the plate and the ground wire from the jack goes to the volume pot, the problem is that the plate is in contact with the hot somewhere, so when they're brought together it shorts the output.

Funkfingers

+1 The problem could be a solder blob or the exposed end of a wire, bridging to the plate.

How is the tone control connected to the rest of the circuit? Does it still roll off treble when not attached to the control plate?

Photographs would help.

545454

Found it! One of the switch lugs was had bent out of alignment and the jumper wire was touching the casing - having a look in daylight made it much easier.
Thanks for the advice chaps.