wiring new harness in HSS strat - neck tone issues

[tomjonesrocks]

Wild stab - looking for wiring help. I am attempting to replace a harness in a HSS Squier 7 String Strat. I'm having tone control issues.

All 3 pickups "work". The humbucker (Seymour Duncan JB) and middle sound good - the neck pickup sounds like the tone is all the way off/down and neither of the 2 controls have an effect. The bottom tone control turns down the tone of the middle pickup and bridge humbucker. The tone knob in the middle does nothing. The volume knob works properly with all 3 pickups. In the diagram I was sent it seems like the bottom tone knob should affect the bridge and the middle tone knob should affect the neck and middle. The 5-way pickup switch selects the pickups as I'd want (all the way down is the bridge, in the middle is the middle, and up is the neck).

The harness specs are - Oak-Grigby 5 way Blade Switch / CTS 500 K Ohm Volume Control with Orange Drop Treble Bled Mod / 2 CTS 250 K Ohm Tone Controls with 1 "MOD" .047 Oil Filled Tone Capacitor (wired so that the tone capacitor works on both tone controls)

Unsure what else to mention. All of the pickup grounds are soldered to the back of the volume knob. The jack ground is soldered to the bottom tone and the jack positive is soldered to volume. On the Seymour Duncan humbucker, the white and red wires are soldered together and taped off - the black goes to the switch and the green goes to ground.

Trying to attach pics but unsure what to offer -

 

[GuitarStv]

Sounds like the neck tone is going directly to the capacitor. Could be a bad pot that's not providing any resistance, or something funny going on with the wiring there . . . but that's where I'd start debugging with my multimeter.

 

[tomjonesrocks]

Sounds like the neck tone is going directly to the capacitor. Could be a bad pot that's not providing any resistance, or something funny going on with the wiring there . . . but that's where I'd start debugging with my multimeter.

So I do have a multimeter - but am new to this kind of troubleshooting and don't really know what to do with it. What would I be checking specifically?

Editing as I Google guitar+multimeter...am not at all sure what this tells me...
Testing with a multimeter on the outer poles of the tone knobs:
- Lower Tone - .276
- Middle Town - .257

Testing with a multimeter and guitar lead
- JB at Bridge reads 19.5 on the multimeter
- Middle Single coil reads 6.59
- Neck Single coil reads 6.52

How do people learn this stuff? Is there a good resource to start with? Thanks!

 

[GuitarStv]

On the tone pot that's malfunctioning, you have a hot wire going in to one lug, and you have a lug that's going to ground. Put one probe on each lug, and set your multimeter to 500K (or a value slightly higher, maybe 1M?). You should see that when the tone pot is turned all the way in one direction it reads zero (or pretty close to it) and all the way in the other direction it reads about the value of the pot (a 500k pot will read 400 - 600k, a 250k pot will read 200 - 300k). If that's the case, then your tone pot is working properly. If you're only getting zero reading no matter where it's set you either have a bad pot, or you've accidentally bridged between the two which is causing an always on tone sound.

 

[GuitarDoc]

The harness specs are - Oak-Grigby 5 way Blade Switch / CTS 500 K Ohm Volume Control with Orange Drop Treble Bled Mod / 2 CTS 250 K Ohm Tone Controls with 1 "MOD" .047 Oil Filled Tone Capacitor (wired so that the tone capacitor works on both tone controls)

That description doesn't match your picture...picture looks like the Oak Grigsby 3 way, no tone pot for bridge pup, separate tone pots for middle and neck, 2 MOD tone caps (one for each tone pot), and it appears that the switch is wired incorrectly (more picks that show the wires to the switch more clearly would help). What's up with that?

 

[GuitarDoc]

Do a quick test for me...
With the selector switch in the bridge position tap on the poles of each pickup and see which is louder. Then in the middle position tap again, and again in the neck position.

Is the JB (bridge pup) loudest when the switch is in position 1 (bridge position)?
Is the middle pup loudest in middle position?
Is neck pup loudest in neck position?

 

[GuitarDoc]

Hey, tomjonesrocks, you there? Any results, comments?

 

[tomjonesrocks]

Thanks so much for all of your replies here! I discovered that the capacitor on the middle pickup was wired to the same lug as the wire - moving the wire to the far right lug at least allowed the guitar to function.

How it works now is the middle tone controls the tone for the bridge and middle pickups - and the lower tone controls only the neck. Again this doesn't seem all that common a setup - but at least all 3 pickups work and sound good (to me) regardless of the weird tone knob mapping. May look into the latter issue more closely based on the posts above - Thanks again!

 

[eclecticsynergy]

Yah, it's more common - and perhaps more useful - to have one tone for the neck & middle and one for just the bridge.

 

[GuitarDoc]

Yeah, it certainly makes more sense to me to have a separate tone just for the bridge pup. IMO it would be a more useful arrangement for a 3 pup 2 tone pot guitar.