I have 2 strats, one with Am std pickups and another with CS 54's.
With the Cs 54's there's volume loss on positions 2 and 4 of the pickup selector, this doesn't happen with the strat with Am std's.
Are they incorrectly wired or something?

There isn't a significant difference
The neck pickup is the one with the lowest vol, then the middle, and the bridge is the loudest, but it's a minimal difference.

I don't know , a technician did it. I called him to report this and he told me it's part of the "vintage vibe" or something. Is he wack?

could anyone else give me some help plz?

Why do I get a slightly lower volume when I run both pickups at once?

Some slight drop in volume, drive, and bass is normal when you have two pickups on at the same time and they are wired in parallel which is how most guitars are wired , when the two pickups are wired in series—somewhat unusual—the pickups will get slightly louder than a single pickup and you'll get more drive and bass. Resistance is cut in half when you wire two pickups in parallel and inductance drops—this makes output and bass decrease, resistance doubles when two pickups are wired in series and inductance rises.

^From the Lollar pickup site. Cs 54s are identical to each other in terms of DC Resistance, etc., the only difference is the positions they are in. When you are in 2 and 4, the pickups run out of phase, meaning some of the frequencies cancel each other out. Since output is identical between all 3 pickups, it gives you a slightly lower volume (cuz of the lack of certain frequencies you had before). As for the American Standard pickups, I assume (correct me if I'm wrong) the neck/mid/bridge pickups are not identical to each other in design, which means less frequency interference and less volume loss. (Please feel free to correct me on this, I'm not Martian >_>)

_________________
I traded my car in for a microphone.

If the volume drop is really that significant, chances are your middle pickup is wired backwards. Additionally, if you get a rather hollow, nasally sound with little bass and a lot of treble in positions 2 and 4, this is an indicator of same.

_________________
You dig?

It's not a huge volume and gain drop for sure... it's just a little but I can notice.

But you play me on TV! LOL

When two pickups are wired in series with each other, you simply add the resistance of both the pickups. The perceived output/tonality is louder/beefier than either by itself.

When two pickups are wired in parallel with each other, you add the resistance of both pickups and divide by 4. The perceived output/tonality is weaker/crisper than either by itself.

In either case, if the pickups are out of phase with each other, even though the above resistance rules still apply, the output/tonality traits would be even more weaker and rather nasally and devoid of most bass frequencies in comparison.

_________________
You dig?

Then you are fine as this is indeed, normal.

_________________
You dig?

Well, I read that stuff from Lollar and I'd say that just because people make pickups doesn't mean they understand them.

That's said, with three identical pickups the bridge pickup on a Stratocaster is usually the weakest in volume. That is because it doesn't see the low frequency harmonics that increase as you move toward the center of the string. And that is why people do things like put a metal plate under the bridge pickup a la Fralin, or pull the single coil pickup and replace it with a humbucker.

And guess what. If two pickups are in phase some of the signals cancel each other out, because the two pickups aren't in the same physical positions.

No, you should see a little drop in volume in positions 2 and 4 because, as discussed above, the two pickups are in parallel.

Occam's razor, here. The simplest and most obvious explanation is usually right.

_________________
James Burton Upgrade Telecaster
Hot Rodded Am Fat Strat Texas Special (now featuring Kinman Traditional II pickups)
Fender Blues Jr.
SWR California Blonde
Pedals Pedals Pedals