Model J pickup wiring help

[redielg]

Hey everyone I have a 2006 MIM standard Jazz. About 3-4 years ago I got some Model J's installed by some a guitar shop owner in Miami Beach. Recently, my girlfriend bought some parts to put in my bass since she knew I've wanted to buy them. I got some CTS audio pots, a switchcraft jack, cloth wire and a orange drop capacitor.

I bought a soldering kit and I looked up some wiring diagrams on DiMarzio's website. Problem is, the wiring on my bass doesn't seem to match up with their wiring schematics and honestly looks quite fugly. I wish I had looked at the job sooner to be honest.

anyways, is the wiring on my bass correct? or should I follow the wiring diagram from DiMarzio's website when I solder these new parts in? Am I correct in thinking this was a shoddy soldering job? I'm no expert but I feel as if I've seen better work, especially on these forums.

Once money permits, I'll be buying some single coil Nordstrand Jazz pickups, some shielding tape and a Push/pull pot for series/parallel switching. But for now I just want to put the new pots in. HELP.

[joelb79]

That looks fine redielg, all except for the slightly cold solder joint on your bridge pickup volume pot. The one lead that is grounded to the backside of the pot is the cold culprit. Doesn't look solid to me, but I'm sure it makes a connection. Colors are correct, tone pot seems fine from the picture angles. I'd just add some more heat and solder to that bridge pickup pot ground.

[joelb79]

Holy crap I can't believe I missed this but your jack is not wired correctly. There is no ground running to the backside of a pot. this is why you have problems if your having them. I'd double check that jack big time, as it's missing a wire.

/smacks forhead cant believe I missed that on the first look.

[redielg]

yeah every now and then i get a scratchy sound or a strange hum, i figured a ground was loose. but something missing? eek. ill take a look.

[joelb79]

well specifically this picture, I can see the black wire coming from the tone pot into outer space instead of running to the jack. perhaps you took the picture before attaching it?

[darius8]

I have seen a 2004 Fender Am Jazz bass without the ground terminal on the jack soldered.

[Carey]

The ground is through the metal pot cases through the plate to the jack. It should be perfectly fine this way, but we never let a bass go out like that. I prefer to run wires to the pot cases and the jack. This gives us a redundancy factor in case the pots or jack ever come loose.

[Cadfael]

Originally Posted by joelb79

Holy crap I can't believe I missed this but your jack is not wired correctly. There is no ground running to the backside of a pot ...

Hi joelb79,

this is correct!!!
The ground to housing works via the control plate.
This is the "standard non-wiring" for "real Fender basses"!

So, your first comment was correct!
Everything is okay with this wiring and it is 100% "Fender standard".

The changes through the years (including a dotted line for the "ground via control plate") can be studied in my wiring compendium ...

@ redielg:
There are more than 10 ways to wire a Jazz Bass the same - but it looks different! Very complicated for a Newbie ...

You can use the Duncan wiring or use the wiring as it is now.

My compendium is in German - but easy to understand!
Your wiring original wiring is shown in schematic 1.1.45 (page 32 at the moment).
If you like to have a look: http://161589.homepagemodules.de/t29...-E-Baesse.html
(scroll down, click the "Bassschaltungen390.pdf" at the bottom, wait until it is loaded - 6.3MB mit more than 400 pages, store it on your HD)

[redielg]

Alright I'll take a look, thanks guys.

[Cadfael]

The left black wire goes to the bridge.
The right black wire goes to the body grounding (paint).
That's correct ...

If you have a hum/buzzing problem, you can solder a wire from the jack ground to the housings (in line). The buzzing might come from a not 100% connection via control plate.
The wiring of the jack ground is not neccessary but it makes the wiring more secure.

[redielg]

Alright guys help me out. On Sunday I was swapped out the old pots with the new ones and soldered everything with my cousin. I wired it the same as before. Tested it out. Everything turned out great no grounding issues. However, my girlfriend is a total tech junkie and wanted to do it herself. I disconnected everything and let her follow the same wiring diagram. However, something funky happened when she soldered.

When I turn down both volume knobs, I still have sound. Why is this happening? the volumes work otherwise, the volume goes down as I turn the knob, but I reach the end and then there's sound again. This happens with both volume knobs.

[JoeWPgh]

I suspect she has a bad solder joint from one of the pot lugs to it's casing.

[SGD Lutherie]

Originally Posted by Carey

The ground is through the metal pot cases through the plate to the jack. It should be perfectly fine this way, but we never let a bass go out like that. I prefer to run wires to the pot cases and the jack. This gives us a redundancy factor in case the pots or jack ever come loose.

+100

[redielg]

fixed it! I'm a happy happy camper. I also soldered a ground to the jack like you guys said. thanks for the help guys!

I'll probably be asking for help again once I order the new pups, copper shielding and push/pull pot.