Restoring 70s STRAT low pickup volume

[brunobliss]

Hey guys, finally convinced my father that his old strat would be better off in my hands

Noted problems:

Neck and Middle pickup are barely present (very low volume)
Volume POT needs to be turned nearly all the way up to a 10 to get any decent sound from the guitar (anything below a 9 e is barely listenable)

Surprisingly the bridge pickup is the loudest (?) i'm wondering where i should start to look first? You guys think warming the soldier on the pickups would have any effect?

thanks in advance!

[The Dude]

Check the pickups with a meter to see if they are in reasonable spec. I doubt the pickups are the problem. They usually work or they don't. I'd start by cleaning the pots, jack, and pickup selector switch. You might just have connection issues. What are you plugging it into for testing? If your test rig is expecting a line level input, of course volume will be low.

[brunobliss]

I'm comparing it to my 2018 strat plugged into AMP and audio interface, volume is really low on the neck and middle (vintage strat)

I'll start by checking the pots and switch as you said, question, is it OK to spray these with contact spray?

[Leo_Gnardo]

Check the pickups with a meter to see if they are in reasonable spec.

Good advice there. You can get a good idea what the pickup resistances are without having to take the guitar apart. Dial volume full up. Plug a guitar cable into the jack, with an ohm meter measure shaft to tip with the selector set to bridge, mid, neck. Should see somewhere between 5k and 10k ohms. If you see a measurement like 250K then that's the volume control itself, and either the pickup has gone open circuit, or let's hope there's a bad connection in the selector switch or maybe a pickup wire broken loose from it.

Also - good to check if there's been any modification done. A strat recently showed up here with the mid pickup totally disconnected, on purpose. Also one of the tone controls. A mod done for the owner who was trying to emulate tele tones. 3 way switch was wired bridge / both / neck. Go figure. It had my head spinning for a little while.

[The Dude]

......is it OK to spray these with contact spray?

Yes. Deoxit or similar is what I'd use.

[olddawg]

Honestly.. if you are not familiar with this type of work, what types of solvents/cleaners to use, don’t have soldering skills, or how to check things and where to start.... a vintage Strat is the wrong thing to learn/practice on. Spend $125 and have a good shop (not GC or similar) straighten it out and do a setup. It’s money well spent. Practice repair mod/skills on $100 beaters. More than likely it’s a dirty selector switch if it isn’t simply pickup height. Also pickup magnets can degauss over time.

[Mick Bailey]

+1.

I get a lot of instruments where a new owner has attempted work and it's gone wrong, devaluing the instrument and costing more to put right. I have an expression -"Picking up a turd is one thing, picking one up that someone has trodden in is something else..."

One killer is contact cleaner - there are many products that will render a pot unusable either right away or after a few days or weeks. There's every chance that the problem is minor and an easy fix for someone experienced. At the same time it can have a setup to bring it into full playing condition. I advise against getting anywhere near the pickups with a soldering iron and you say "warming" which suggests inexperience in this area. You have to diagnose what's wrong through measurement, observation and deduction before taking any action.

If you insist on proceeding yourself, then the best course of action is to do this interactively here, a step at a time and post pictures.

[brunobliss]

Good advice there. You can get a good idea what the pickup resistances are without having to take the guitar apart. Dial volume full up. Plug a guitar cable into the jack, with an ohm meter measure shaft to tip with the selector set to bridge, mid, neck. Should see somewhere between 5k and 10k ohms. If you see a measurement like 250K then that's the volume control itself, and either the pickup has gone open circuit, or let's hope there's a bad connection in the selector switch or maybe a pickup wire broken loose from it.

Also - good to check if there's been any modification done. A strat recently showed up here with the mid pickup totally disconnected, on purpose. Also one of the tone controls. A mod done for the owner who was trying to emulate tele tones. 3 way switch was wired bridge / both / neck. Go figure. It had my head spinning for a little while.

Great tip indeed, after spraying with switch (without removing the scratchplate), all pots maxed out, multimeter set to 20k readings:

neck: no reading
neck\middle: no reading
middle: no reading
middle\bridge 7.30k
bridge: 7.30k

Honestly.. if you are not familiar with this type of work, what types of solvents/cleaners to use, don’t have soldering skills, or how to check things and where to start.... a vintage Strat is the wrong thing to learn/practice on. Spend $125 and have a good shop (not GC or similar) straighten it out and do a setup. It’s money well spent. Practice repair mod/skills on $100 beaters. More than likely it’s a dirty selector switch if it isn’t simply pickup height. Also pickup magnets can degauss over time.

I'm not entirely an electronics rookie and i been doing the setups for all my guitars but nonetheless would never venture into something i'm not 100% comfortable doing will probably only try the non evasive stuff.

[olddawg]

Great tip indeed, after spraying with switch (without removing the scratchplate), all pots maxed out, multimeter set to 20k readings:

neck: no reading
neck\middle: no reading
middle: no reading
middle\bridge 7.30k
bridge: 7.30k
I'm not entirely an electronics rookie and i been doing the setups for all my guitars but nonetheless would never venture into something i'm not 100% comfortable doing will probably only try the non evasive stuff.

Just be really careful with sprays and solvents. They tend to creep and degrade plastics like pick guards and soak into exposed wood. A tiny spot of Caig Deoxit is all you need. Be very careful with the pickups. They are valuable by themselves. If open they may be repairable without rewinding. Many times the problem is where the coil wires meet the lead wires. But you really need to know what you are doing not to cause more harm than good.

[Leo_Gnardo]

It looks like the pickguard will have to come off for a closer look. It's time to think about finding a guitar tech you can trust, and maybe even watch if he'll permit it. Personally I'd have no problem but others might not want someone looking over their shoulder. If the wiring is intact and switch OK then the pickup resistances can be measured at the "button" solder connections on the back of each one. Should be done very carefully to avoid breaking hair thin winding wires attached to them, and hit helps to have needle sharp points on the meter probes.

[brunobliss]

Well i took a peak and found a loose wire, looks like it detached from the ground wire screwed to the body

[The Dude]

So did that fix it?

Here's a strat wiring diagram if you need to figure out where the wire goes.

https://www.kobra.hr/Schematics/GUIT...ter%2070-s.jpg

[Helmholtz]

Well i took a peak and found a loose wire, looks like it detached from the ground wire screwed to the body

Where does the other end of that wire connect (not clear from the pictures)?

[brunobliss]

So did that fix it?

Here's a strat wiring diagram if you need to figure out where the wire goes.

https://www.kobra.hr/Schematics/GUIT...ter%2070-s.jpg

Well i did connect that loose wire to the part that screws to the body and sprayed the switch with contact spray. It's now too late to properly test it without upsetting the neighbors but the neck and middle are now noticeably louder! Still not as loud as the bridge which is from my experience the "thinnest" sounding pickup on strats (at least on my other two).

Where does the other end of that wire connect (not clear from the pictures)?

The wire with the screw goes to the output jack cavity where it connects to another screw equally attached to the body, so it was basically doing nothing. The claw is connected to the volume pot and continuity checks out.

I'll leave this gem as is and get it professionally setup ASAP

thank you guys for the help!

[The Dude]

I'm curios as to what your pickup DCR readings are with the wire reconnected. Can you remeasure and post them for each pickup as you did in post #8?