#170002  by wpmartin1979
 
Hello, I need some help figuring this out. I am doing a pickup swap on this Carvin DC135. The guitar has a Single (neck) Single (middle) Humbucker (bridge) configuration.

Instead of a 5 way switch the guitar has three DPDT switches (one for each pickup). I have replaced all the switches with brand new switches, the old switches were exactly the same but a bit warn out.

The problem is with the neck pickup. The middle and bridge pickup are working fine. The neck pickup does not work when wired the way that the guitar was previously wired (see diagram). The pickup has been tested and is fully functional.

When the switch for the neck pickup is engaged no sound comes through and both of the other pickups are muted as well. When the switch is disengaged both the middle and bridge pickup function perfectly.

The neck pickup DOES work when I put the hot lead on the same connector (upper left) where the wire from the volume pot is attached, however the pickup remains permanently on and the switch has no effect. The other two pickups also function this way, but the neck pickup doesn’t turn off.

The neck pickup does not work at all if I touch the hot wire to any other connector on the switch.

I have attached pics and a diagram for reference.

Can anybody help me figure this out?!?!? I am stumped! The guitar was working fine with the stock pickups when it was wired this same way.

Thank you in advance for any thoughts!

Pickups: DiMarzio SD1 (neck), DGN JG Single (middle), DiMarzio Super 2 (bridge)

BTW the extra wires and switches you see are for an OBEL that I am installing and a kill switch for the bridge. The OBEL is completely bypassed right now while I figure this out so it’s having no effect on the signal path.

The kill switch is only connected to the bridge and is functioning properly.

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Upside down

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Last edited by wpmartin1979 on Sat Feb 20, 2021 4:40 pm, edited 3 times in total.
 #170009  by lbpesq
 
My initial impression is that it’s either a bad switch or a grounding issue. I would try to isolate the problem. You might try swapping the neck PU switch with one of the other two switches and see if the problem follows the switch of remains on the neck PU. If it follows, you’ve got a bad switch. If it stays on the neck PU, you have a wiring issue. Hope this helps.

Bill, tgo
 #170011  by mkaufman
 
With this wiring approach, the bridge and middle hot signals run through the neck pickup switch. Since engaging the neck pickup switch cuts out the other pickups, I suspect their input to that switch is being connected to ground, or just losing continuity to the switch hot output lead.

I would look at the following:

- is the neck pickup switch the same as the others (ie: on/on).
- is the neck pickup wired backwards or just wrong. It appears that the neck pickup is different from the middle pickup.
- use a meter to verify the neck pickup switch behaves as expected and that signal is passed properly through the switch.

ace

Last year I rewired a guitar and one new switch was malfunctioning. I confirmed via a meter and obtained a replacement which resolved the issue.

ace
 #170012  by mkaufman
 
One more recommendation: I would cover the exposed ground wires to ensure they don't come in contact with anything else. I have found with tight control cavities, this can happen when stuffing everything in and covering the cavity, although, more so with front-loaded guitars (ie: Strats).

Electrical tape will work, however, I find that painters tape is easier to deal with, especially if you need to remove the tape.

ace
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 #170013  by wpmartin1979
 
mkaufman wrote: Sat Feb 20, 2021 11:19 am With this wiring approach, the bridge and middle hot signals run through the neck pickup switch. Since engaging the neck pickup switch cuts out the other pickups, I suspect their input to that switch is being connected to ground, or just losing continuity to the switch hot output lead.

I would look at the following:

- is the neck pickup switch the same as the others (ie: on/on).
- is the neck pickup wired backwards or just wrong. It appears that the neck pickup is different from the middle pickup.
- use a meter to verify the neck pickup switch behaves as expected and that signal is passed properly through the switch.

ace

Last year I rewired a guitar and one new switch was malfunctioning. I confirmed via a meter and obtained a replacement which resolved the issue.

ace
Thank you so much for the suggestions!

The problem initially was occurring with the stock switch. I thought it could be a bad switch, so I put a new switch in ...same problem. While I was at it, I decided to replace all three switches, they are all the same type of switches.

The neck pickup has only two wires, a white and a black. I’ve tried switching them around but it doesn’t work. I’ve also tried putting them together, it works with noise as the pickup is essentially in grounded.

I suppose I need to look more closely at this grounding issue. You say that “their input to that switch may be losing continuity.” Would that be the wire from the volume pot to the neck switch? As far as I can tell it runs directly to the switch without interference.

Is there anywhere else where the neck switch could be grounding out?

BTW I do plan on covering the bare wires, I just have everything in trial/error test mode right now to try and figure this out!
 #170014  by wpmartin1979
 
lbpesq wrote: Sat Feb 20, 2021 10:37 am My initial impression is that it’s either a bad switch or a grounding issue. I would try to isolate the problem. You might try swapping the neck PU switch with one of the other two switches and see if the problem follows the switch of remains on the neck PU. If it follows, you’ve got a bad switch. If it stays on the neck PU, you have a wiring issue. Hope this helps.

Bill, tgo
Bill thanks for the suggestions! This is the second switch with the same issue. The first switch was the stock switch that I then replaced with a new switch, same problem. Looking at the diagram, do you see any place where I may specifically be having a grounding issue?

Thanks again?
 #170016  by lbpesq
 
While I’m not a wiring guru - I can follow a wiring diagram and am comfortable with a soldering iron, but I don’t pretend to understand it all - if the original switch was doing the same thing, and the new switch didn’t fix anything, I suspect the switch isn’t the problem.

I see you are using DPDT switches. With one position being “on” and one being “off”, what is happening in the third position? It seems to me (again with a big “if”) from the diagram that you are using them as a single throw switch. One thing I would try is moving the wire coming from the volume from the upper left lug on the neck switch to the middle lug, just below it where the wire from the other two switches is connected and see if that works better.

Bill, tgo
 #170017  by TI4-1009
 
I would try to follow the signal with a meter or continuity tester.
 #170018  by space
 
Try this:
1 Leave all ur hot pu connections to the switches as u hav them
2 wire the middle lugs of all your switches to the V pot right lug (as ur looking at it from the bottom) the cntr lug (V pot) wire to the jack
3 left lug V pot to ground
4 wire all your H pre-switch to the left lug T pot
5 from the middle T pot lug attach ur cap
6 other side of cap goes to ground

http://www.1728.org/guitar.htm

Similar to the strat example w/o the second T pot
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 #170019  by wpmartin1979
 
lbpesq wrote: Sat Feb 20, 2021 2:38 pm While I’m not a wiring guru - I can follow a wiring diagram and am comfortable with a soldering iron, but I don’t pretend to understand it all - if the original switch was doing the same thing, and the new switch didn’t fix anything, I suspect the switch isn’t the problem.

One thing I would try is moving the wire coming from the volume from the upper left lug on the neck switch to the middle lug, just below it where the wire from the other two switches is connected and see if that works better.

Bill, tgo
Bill, once again you are a genius! This worked ... problem solved! I feel stupid, but I guess I’ve put a lot of cloudy stuff in brain over the years :rasta:
Thanks again!!! Thanks
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 #170020  by wpmartin1979
 
space wrote: Sat Feb 20, 2021 3:52 pm Try this:
1 Leave all ur hot pu connections to the switches as u hav them
2 wire the middle lugs of all your switches to the V pot right lug (as ur looking at it from the bottom) the cntr lug (V pot) wire to the jack

http://www.1728.org/guitar.htm

Similar to the strat example w/o the second T pot
This worked thanks!!!!
 #170022  by lbpesq
 
wpmartin1979 wrote: Sat Feb 20, 2021 4:26 pmBill, once again you are a genius! This worked ... problem solved! I feel stupid, but I guess I’ve put a lot of cloudy stuff in brain over the years :rasta:
Thanks again!!! Thanks

Sorry, but that excuse won’t work with me. When it comes to the “cloudly stuff”, as a former member of the BOD of national NORML, a current member of the BOD and state legal coordinator for California NORML, and a co-author of California’s Prop 215 (nation’s first medical cannabis law), I’ve had as big a share of “cloudy stuff” as anyone!

hehehehe

Glad I could be of assistance in getting you back up and running.

Bill, tgo
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