Wiring help needed - Strat with series blender

[Anonymous]

I hope one of you clever people out there can help me with this one, because it's beaten me! I'm trying to wire up a Strat using this diagram.

I'm sure I've connected everything up OK, but it doesn't seem to work properly. There's probably something blindingly obvious to one of you, but not to me, I'm afraid.

With the blender pot turned anti-clockwise, the series wiring seems to work. The problem is in the normal position with the blender fully clockwise - the only position that works is the middle position, which selects the middle pickup.

Can anyone please work out what the problem is here? Is there a fault with the diagram? Have I read it wrongly? I'm baffled here, so all help will be gratefully accepted.
Thanks.

Mike

 

[AlanN]

Any shots of your actual wiring, Mike?

 

[mirrorboy]

Diagram looks OK to me. Have you connected ground wires from 'series' and tone pots to the volume pot?

 

[Anonymous]

Diagram looks OK to me. Have you connected ground wires from 'series' and tone pots to the volume pot?

Yes

 

[Anonymous]

Any shots of your actual wiring, Mike?

All new pots Alpha 250 B volume, Alpha 250 A master tone, Fender 250 no-load blender pot. .022 cap courtesy of JohnA.

 

[mirrorboy]

I think you have a connection missing from the unused tone pot terminal to ground. Shouldn't there be another connection on the volume pot, from the casing to the ground lug?

 

[AlanN]

Hmm, possibly. The diagram does say that the 2nd output from that pot should go to ground, but I can't see why with it being the master tone pot. Try it anyway - I'll keep looking.

Edit: hmm, no it doesn't - there's no black blob indicating a solder point on that outside leg.

Looks fine to me... time to start tracing for continuity!

 

[Anonymous]

I'm not sure I follow you. Here's the volume & master tone pot from a Goldie on which I replaced the volume pot a couple of days ago, & which works fine. It's the same as on the one which isn't working properly, isn't it?

I assumed that the problem would be with the switch?

 

[Anonymous]

Looks fine to me... time to start tracing for continuity!

How does one do that? :-?

 

[AlanN]

Your special friend, the multi-meter!

Switch it to ohms (resistivity) on its most sensitive and check that it's working - a value of "1" means an open circuit; touch the two probes together and it should drop to (near) zero to show that both sides are linked in a circuit.

Now you'll have to check every link in your wiring chain - start from the pickup outputs down to the hot tip on the jack. If there's continuity along there, then check the grounds for the same pickup. If there's no hot continuity, start breaking that journey down into little steps until you find where the break is - it'll give you a much better idea of which joints to check or which parts to replace.


Edit: in less general terms:

Switch to parallel mode on the blender.

Switch to position 1 (bridge only). Make sure vol and tone are on full.

Put one probe on the hot lead from the bridge pickup. Plug a 1/4'' guitar lead into your output (makes measuring a bit easier) and touch the other probe to the tip of that lead. If your meter still says 1, then there's no hot signal.

Now take the probe lead you used on the guitar lead tip and put it on switch terminal 3 (where the hot signal from the bridge pickup comes in) and on terminal 4 (where the hot signal from the switch is output). Should definitely see continuity (reading approx. 0). Keep "hopping" along each wire on this chain.

 

[Anonymous]

By the way, my middle pickup (Seymour Duncan 5-2) is RW/RP. Is that relevant?

 

[Anonymous]

Switch it to ohms (resistivity) on its most sensitive and check that it's working - a value of "1" means an open circuit; touch the two probes together and it should drop to (near) zero to show that both sides are linked in a circuit.

Edit: in less general terms:

Switch to parallel mode on the blender.

Switch to position 1 (bridge only). Make sure vol and tone are on full.

Put one probe on the hot lead from the bridge pickup. Plug a 1/4'' guitar lead into your output (makes measuring a bit easier) and touch the other probe to the tip of that lead. If your meter still says 1, then there's no hot signal.

Now take the probe lead you used on the guitar lead tip and put it on switch terminal 3 (where the hot signal from the bridge pickup comes in) and on terminal 4 (where the hot signal from the switch is output). Should definitely see continuity (reading approx. 0). Keep "hopping" along each wire on this chain.

Maybe I'm just failing to grasp this completely. My multimeter's sensitivity is set automatically.

When I do this:

Put one probe on the hot lead from the bridge pickup. Plug a 1/4'' guitar lead into your output (makes measuring a bit easier) and touch the other probe to the tip of that lead. If your meter still says 1, then there's no hot signal.


I get a reading that fluctuates around 03.6 ohms. What does that tell me?

:-?

 

[JohnA]

3.6 ohms is close to zero, (you should get a similar reading if you touch the two probes together) that means there is a good connection, or continuity, between the two points.

 

[Anonymous]

3.6 ohms is close to zero, (you should get a similar reading if you touch the two probes together) that means there is a good connection, or continuity, between the two points.

Is that good or bad?

When I touch both probes together I get 00.0

 

[JohnA]

take a piece or wire, or a guitar lead and check from one end to the other, is that about 3-4 ohms, if so then it's close enough to zero.

If you are checking for continuity, i.e. a good connection then it's good

 

[Anonymous]

I've given up! I think there is something fundamentally wrong with that series blender wiring diagram, though I can't work out what. I just cant be bothered to waste any more time on it.

I've just wired it up using the parallel blender wiring.....

.......& it works fine.

I would still like to try the series blender at some future date, but only if somebody can make sense of the diagram for me. I'm convinced there must be a flaw or a misprint in it somewhere.

 

[AlanN]

What happened as you blended between the two, Mike? I'm wondering if it's the right type of blend pot...

 

[AlanN]

Ah, shame you changed it really as we could have talked you through troubleshooting it. Might have taken a while but still!

 

[Anonymous]

Ah, shame you changed it really as we could have talked you through troubleshooting it. Might have taken a while but still!

Well I waited & waited.....

As I said before, when the blender was turned to switch in the series wiring, it seemed to work. The problem was in the "normal" position - the only pickup that worked was the middle - nothing from the other 4 positions.

And as for it being the wrong blender, it's a Fender 250 no-load pot. And it works fine with the parallel blender diagram, so that surely rules that out?

 

[AlanN]

Well, yes, but we're working too...!

What I mean is - as you turned the blender from one extreme to the other, what happened? Just everything dropping out (ie. getting quieter), or did it all just cut out at once?