Tracking ground issue on new pickup install

[skiltrip]

I just put in a MojoTone wiring harness and a set of SD pickups... JB bridge and Jazz neck.

I think I did most of it right, sounds right, but there is a definitely grounding issue.
I soldered the ground wire to the tone pot as per the SD wiring diagram. But there is a buzz. It goes away when I touch the guitar cable, or touch the toggle switch, or pickups, but doesn't go away when I touch the bridge or strings.

I figure either I didn't solder it properly to the tone pot, or maybe it disconnected on the bridge end of the cable. I'm open to suggestions based on what I said, but also curious, where does the ground wire typically connect to the bridge on an SG?

Hoping to get this straightened out soon. Thanks!

 

[shadowfire90]

Re: Tracking ground issue on new pickup install

I make all my own wiring from scratch so I'm not too familiar with mojotone. What wiring do you have.

With ground think of it like a security patrol.

string ground
pot to pot in a straight line , no over lapping or going back and forth - with a les paul you make a C with a tele or strat just straight down
to the input jacks sleeve

Also be sure that your pickups color codes are correct. Series out of phase which occurs when you do not install the pickups with the right color code can happen

As a reminder the color code with SD pickups is
black - hot lead
red / white - solder together - put tape over (coil split)
green / bare - solder to the back of a volume or tone pot

 

[skiltrip]

Re: Tracking ground issue on new pickup install

The wiring harness is basically this.
I soldered the ground wire to the back of the tone pot on the bottom left.
I also did solder red and white together, taped them off, for both pickups
Green and bare are soldered together and are soldered to the ground point at each respective volume pot.
Black on each pickup is going to the appropriate connector on each volume pot as per the SD wiring diagram.
Mojotone wiring:

 

[Gtrjunior]

Tracking ground issue on new pickup install

Did you ground it the output jack too?

Edit: just saw that it is part of the harness.

 

[skiltrip]

Re: Tracking ground issue on new pickup install

Thanks, yes, most of the work is done on this harness. Wish I'd taken a picture of the wiring in my guitar cavity but I will add it later today.

 

[Ayrton]

Re: Tracking ground issue on new pickup install

You can take a separate piece of wire and test your grounds. You could just have a cold joint.

You can also solder your grounds directly to the bus wire connecting the pots. This makes a little easier on you and removes the risk of cooking the pot.

 

[shadowfire90]

Re: Tracking ground issue on new pickup install

this is the approach. I like Ayrton's suggestion as well about cold solder joints. Regardless of how the capacitors are hooked up this is how I do les paul wiring grounding.

Remember with input jacks my dumb way to remember it is "SG" like a Gibson... sleeve, ground - sleeve is metal all the way to the base
tip is non-conductive at the base

View attachment 102184

 

[skiltrip]

Re: Tracking ground issue on new pickup install

I think I found the issue. The U shaped ground line was broken off on the lower left tone pot. Might be some cold solder stuff happening too. Will attack it tonight. Thanks everyone.

 

[VinceT]

Re: Tracking ground issue on new pickup install

I think I found the issue. The U shaped ground line was broken off on the lower left tone pot. Might be some cold solder stuff happening too. Will attack it tonight. Thanks everyone.

Make sure you check bridge continuity while you’re in there - if you have a multimeter, check for 0 Ohms resistance between the bridge itself and the wire emerging into your control cavity. I had that wire break on one of my guitars a while back.


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[skiltrip]

Re: Tracking ground issue on new pickup install

Yeah. All good. I fixed it. I checked continuity with my multimeter and that's how I located the disconnect on that ground wire going pot to pot. It was raised ever so slightly and I had to look really close to see that it was disconnected. The separation was just about thin as a piece of paper. Guitar is nice and quiet now though. Thanks everyone!