Yesterday, while stopped in daytime traffic in my '92 SSE */c, I pressed the window DOWN switch and held it for a couple of seconds while the window already happened to be all the way down. To my surprise, the engine idled a little more rough and the boost gage needle moved up a little bit (maybe 1/16") while the window switch was pressed. I released the switch and the engine idle and boost gage needle returned to their previous conditions. I repeated this test consistently using a window DOWN switch for a window that was already down, and the window UP switch for a window that was already up. This proves that the change in engine/boost behavior was no coincidence.

Have any of you ever noticed this before? Is it normal

It seems odd to me - maybe there'* a problem with an electrical ground somewhere, or maybe my alternator isn't regulating the voltage well enough? It'* an AutoZone DuraLast Gold alternator that'* not very old, and the battery isn't very old either.

I'll try this same test with my '93 SSEi and post the results as soon as I get a chance, but my wife drives that car.

That window motor pulls a substantial amount of current so the alternator had to keep up with the load which in turn took more engine power and that was reflected in the boost gage.

You are correct. Time to pull all battery cable connections at all ends and check/clean them thoroughly.

Well, to answer my own question, I tried the same test on my '93 SSEi, and the boost gage did the same thing (it moved up just a little), so either this is normal behavior, or both of my bonnies have the same problem.

It probably has to do with the extra load put on the electrical system and the engine compensating for it.

I did try it on my car. No change in engine.