Grrrr.. new P90s

[KaiserSoze]

Okay.  Sorry in advance for my frustration.  I've re-wired a les paul copy with two P90s EXACTLY like the attached diagram and have only the bridge pickup working.  No neck pickup at all or middle position.  I've triple checked the solders and where everything goes.

If I have a standard Les Paul type setup what is the probable culprit if only the bridge pickup works?  Bad pot?  Bad pickup? 

 

[Updown]

:icon_scratch:  Isn't the ground and live the wrong way around on the Toggle switch.
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=2h_2v_2t_3w

http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=p90

 

[pabloman]

That's 2 different switches being represented. They are both correct. I don't think I've ever seen a switch like the first one. Either way though the two tabs joined together will be the output.

 

[Cagey]

The switch depicted in the OPs diagram is foreign to me. Using the typical switch, that wouldn't work.

This is why wiring diagrams suck. Without a schematic, we don't know how that switch works.

 

[KaiserSoze]

Switch is the original and wired the same way it was before I replaced the pickups, so I cant imagine that changed.

Oh. And when bridge volume is down or the toggle is in the middle or neck position I can hear a radio station.  I can't think a pickup would be bad but could a bad pot make it do these things?  If I'm hearing a radio station, is that a ground issue.

I realize this is prob impossible to diagnose with the info given.  I'm just trying to avoid the pain of replacing that pot just to see.  Thx

 

[Cagey]

Follow the diagram at the link Updown posted.

 

[KaiserSoze]

Can someone just go to my house and get it done for me so when I get home from work this afternoon I dont have to screw with it anymore.....anyone??  Beuler??

 

[Alfang]

Over the years we've had MANY posts just like this, where the OP says I wired it just like this diagram,

Only to discover later after many back and forths and pics that he indeed missed something in his efforts.

So having said that: do you have a continuity tester? If not get a cheap one and start checking. You should be able to follow your signal from one point to another and also ensure that your pups aren't "open"  keep in mind that a continuity tester will read through a pickup, so use your switches to isolate in or out your pups.

Study your diagram and figure out before you check, what kind of continuity result you should see, then when it differs, figure out why.

Or rip it apart and start over. One last thing, I didn't check, make sure you find the needed diagram from seymour duncan.com

 

[leo12.]

Do the P90s have a metal braided wire & 2 other wires? Is the braided wire grounded?
If you pick up some  mini crocodile clips & some wire you could do some checks.

 

[KaiserSoze]

Hi.  P90s have three wires.  I confirmed which is hot and the other two go to ground.  I also re-did all the wiring in a two-volume, master tone configuration from the Seymour Duncan site.  I installed a new swithcraft toggle with the traditional wiring. 

Still have the same problem of the bridge pickup sounds great while the neck and bridge settings have a tiny whisper of sound. 

I have a multimeter.  Can I just test the signal path between each solder while the guitar is fully wired and look for something weird ?  Also, can I take a reading between the input and output of each pot while it is wired?  If so, what should I get for ohm readings?

Is a reading between the ground and hot of each pickup accurate if it is taken while they are wired?

Any suggestions for a book where I can learn this stuff so I dont have to come back here sounding like an idiot?

 

[Cagey]

Your neck/bridge pickups may be out of phase. That would cause the symptoms you describe to appear. Swap the hot/ground on either one of them (not both), and see how that works.

 

[leo12.]

Neck position should work like bridge regardless of phase, its when both are selected it would be out of phase. Do you have croc leads? You will  have to unsolder the neck pu so you can check it with the meter, set the meter to Ohms touch the braid & earth to one probe the
hot to the other, it should read close to the specs of the manufacturer. If it does connect
the neck pu straight to the output jack,(hot & ground)  link a croc cable to the bridge ground (no controls) you'll know if the neck pu is working.
Then you can check the pots etc.
You could unfasten all the controls & mount them on a piece of card with the same alignment
as the guitar, might be easier to work on & less frustrating.

 

[KaiserSoze]

Not out of phase but that was a good idea.  I think I might see if I can get it to work if I grab some lighter fluid and do a Hendrix on it.  or I'll just pretend its a Les Paul Jr.  Thanks

Leo.. I'll try that, thanks  :icon_biggrin:

 

[Patrick from Davis]

For the same sort of check that Leo mentioned, but simpler for me, I check the resistance across the leads.  It should be a number of K-ohms but nothing over 25K.  If it is an open circuit, well, there is a problem.
Patrick

 

[-CB-]

P90s have two wires.  They have hot and braid.  A knockoff P90 may have three... hot, return, and braid.

I suspect not an open coil, but a shorted coil.  The short would effectively ground out the bridge pickup whenever the neck pickup was in the circuit.

Unsolder the neck pickup... see if it works in "both" position of the switch.

 

[Cagey]

Speaking of braid...

The outer braid on that type of wire is also ground, so care has to be taken when installing the pickguard or covers, etc. that the braid doesn't touch any signal-carrying conductors or terminals on the switches/pots. That'll short things out so you get no output.