I have an old Teisco "gold foil" pickup with a red, a green and a black wire.
I want to connect it to an existing harness with a volume and jack already connected; the harness has a red, a white, and what appears to be an unshielded wire.
Which pickup wires "twist up" with which harness wires?
I'll attempt a photo if this is not a straightforward question.
Replies
Lots of variations on those pickups, but the common with the colors you mention would be: Green - pickup chassis ground, Black coil return to ground or -, Red is coil positive/hot or +.
Wire the Red wire to a switch and then to volume or straight to volume, wire the Green and Black to the back of the volume pot. All Pots, jack negative and bridge should be grounded.
Tried to take pics but they sucked. So:
At the pickup, the green wire is soldered to the metal "ear" and the black and red appear to be attached to the copper windings of the pickup (hard to tell exactly though).
I presume that the green is indeed the ground and attaches to the unisulated wire, then red to red and black to white.
To be thourough, the connections at the jack are: white is soldered to the pot at position 1, a red wire is soldered to position 2 and another red is soldered to position 3.
One of the two remaining wires on your harness is probably connected to the uninsulated one... you can trace that back from the case on one of the pots. (probably white)
If we presume the red wire is the signal wire (I'd say your 90% right - not 50/50) then the corresponding red wire on your harness will go to one outer pin on the volume pot. The opposite pin on the volume pot is ground. The center of the volume pot should go to output jack tip...
The other remaining wire on both sides should connect to ground and the ring on the output jack.
Sounds like you have it right to me.
The trick here is two wires on both sides should be ground... one is for shielding the wire and pickup ...
I hope this makes sense.
Pics would help... you can't break anything by wiring it wrong.
Thanks for the reply. My electrician brother insists that green is ground and goes to the uninsulated wire. Nevertheless, red goes to red and I've now increased my odds to 50/50. Probably/maybe.
I'm okay behind the business end of a drill or a hand saw, but I'm totally useless with wires and solder and schematics and preventing death by electrocution.
Signal ground (common) and chassis ground (earth) are different, but almost always wired together. much like a 3 prong 110VAC outlet has a hot, common, and ground, but back in the panel the common and ground are wired together.
A pickup will "warble" juice back and forth like a see-saw with each wave of the vibration going up, then down, and we arbitrarily pick one wire and call it signal and the other as common/reference/ground. If you are counting how many see-saws your kids do, you can count how many times Billy goes up, or how many times Sally goes up, its the same. With a single pickup it doesn't matter which end is which. It only matters when you have multiple pickups and you need to make sure the see-saws are going together and not opposite each other.
Chassis ground is the strings/bridge/cookie-tin/volume-tone-pot-body/stuff that picks up noise from the fluorescent lights overhead and connecting signal ground and chassis ground to each other makes the noise get lesser.