What would cause reduced pickup resistance reading?

[rmackowsky]

Testing wiring with multimeter before I install into guitar. Neck pickup should be 7K, but reading not quite 5K. Middle and bridge reading correctly (7K, 15K). Ive tested at the pickup, as well as the switch and output wires to jack. Switch was in correct position when testing. Ground connections all reading good. What would cause this?

To clarify - all pots were turned up to max, and everything is connected including the pick ups. I measured the pick ups before installing- the neck and middle matched the specs which is 7K. The bridge also matched spec which is 15 K. My main concern is that I screwed something up with the wiring causing the reduced resistance in the neck pick up. I did slip a bit with the soldering iron and managed to melt part of the insulation around the middle pick up wires, but that’s not the one giving me the issue.

Here's the wiring diagram (cap is actually .033):

 

[freefrog]

Which pickups in which guitar with which pots?

EDIT: just seen your schematic, posted while I was writing this.

A (low reading) 25k tone pot instead of a 250k could do that in a Strat and such mistakes happen - I've mounted once a 50k pot instead of a 500k although I'm accustomed to guitar circuits.

EDIT - Blade switches are not always reliable and can cause "bleeding" between pickups, FWIW.


Oh, and... damaged coils rather tend to give "infinite resistance" readings (open circuit) than reduced DCR.

 

[pjd3]

I just cranked out some math and 250k in parallel with 7k is about 6.8K. If there was a 25K pot in full parallel it would be around 5.4K which is very close to what you are reading on your multimeter. Its always an iffy thing measuring resistances inside a circuit unless your sure exactly what is going in parallel with that resistance.

DCR is pretty much a static value based upon the amount of copper or conductor between the 2 points that are being measured. Unless there was a big mistake in the amount of windings/wire length in the pickup, I would never expect that huge of a mistake being made in the making of the pickup. A short inside a coil could do that but, usually that's only if there was an over-current that melted the pickup wire insulation. Not likely in that case.

Best,
Phil Donovan