sonic
Rookie Solder Flinger
Posts: 17
Likes: 0
|
Post by sonic on Feb 5, 2014 13:38:17 GMT -5
A friend has asked me too look at his guitar's wiring and I can't work it out. I'm hoping someone here will be able to answer this straightforward question before I demolish the entire wiring loom in a fit of frustration!
The neck pup is a humbucker, rating about 6.5K
The bridge pup is a traditional single, rating about 6.4K.
However, when wired to the 3-way switch the neck pup on its own has full power, but switch to both or to just the bridge and for some reason the output for both is 3.25K.
I don't get it. Any ideas to save an old man's sanity?? Please?
|
|
|
Post by JohnH on Feb 5, 2014 14:08:06 GMT -5
A friend has asked me too look at his guitar's wiring and I can't work it out. I'm hoping someone here will be able to answer this straightforward question before I demolish the entire wiring loom in a fit of frustration! The neck pup is a humbucker, rating about 6.5K The bridge pup is a traditional single, rating about 6.4K. However, when wired to the 3-way switch the neck pup on its own has full power, but switch to both or to just the bridge and for some reason the output for both is 3.25K. I don't get it. Any ideas to save an old man's sanity?? Please? No problem at all, those readings are fine. They are resistance readings, and do not relate directly to the strength of the output. in the middle position, both pickups are wired in parallel, side by side. If both had equal resistance, the combination would have half the resistance - which is roughly what you have here. The output will still be about the same.
|
|
sonic
Rookie Solder Flinger
Posts: 17
Likes: 0
|
Post by sonic on Feb 6, 2014 2:26:56 GMT -5
I agree that the readings are fine for the middle position in parallel, but why does that affect the bridge pup when it's on its own?
|
|
|
Post by newey on Feb 6, 2014 6:11:42 GMT -5
OK, several questions.
First, did you measure the pickups disconnected from the circuit?
Did your friend ask you to look at it because there was a change in the guitar's sound, particularly with the bridge pickup? What was the reason he asked you to look at it? Are you troubleshooting a problem or modifying it?
While a fault in the bridge pickup could cause it to read low compared the factory specs, that should also be reflected in the middle switch position where, as John noted, the parallel combo will reduce the overall resistance of the pair.
If you get 3.25K with the bridge alone, you can't also get 3.25K with the bridge in combo with the neck, unless the neck pickup is not in fact connected in that position. Any other explanation requires us to posit multiple independent faults, an unlikely scenario.
You can perform the "brain scan through a nostril" procedure to calculate resistances of the pickups while in circuit, but with a Tele it may just be easier to disconnect the bridge pickup to measure it. You should also perform the "screwdriver tap test" to be sure all three coils are operating as intended. I say "all three" since, if the neck HB is split in the middle position, that also changes the situation.
|
|
sonic
Rookie Solder Flinger
Posts: 17
Likes: 0
|
Post by sonic on Feb 6, 2014 7:14:07 GMT -5
Problem solved (I think!)
I was asked to look at the guitar because there was no difference between two positions on the switch - just the same sound on bridge and middle position. Thankfully the neck pickup wasn't split - but the wiring was a mess so I've neatened things up a bit.
If you get 3.25K with the bridge alone, you can't also get 3.25K with the bridge in combo with the neck, unless the neck pickup is not in fact connected in that position. Any other explanation requires us to posit multiple independent faults, an unlikely scenario.
It was doing the tap test that solved the problem - a test I should have done earlier: D'oh! The switch was faulty, connecting middle and bridge at all times!
Oh well, you live and learn. I just wish I could learn faster!
Thanks for all the help.
|
|