I searched the forums first for this problem.

2007 LT. Power mirror switch went bad. I replaced it about 5-6 weeks ago. Also, turn signal/headlight switch was replaced couple of weeks after the mirror switch (would not auto-cancel).
It was parked for a while, couple of weeks
Battery was dead!!! I thought a bad cell, it was, and replaced under warranty.
Charged up new battery. A week later it was really low again.
I lowered all windows, took key out, turned all lights off in HHR and in the garage (just to check all interior lights) and saw the light on on the mirror switch.
It also worked and powered the mirrors...with the key out and all light switches off inside HHR.
I pull fuse # 21, 5 amp, in engine fuse box and of course no power and no light on, and battery does NOT drain anymore.
I found the relay that powers the 5 amp # 21 fuse, then marked all same type relays and then switched the "same type" relays around. And still same problem (and then I put all back in original position).
Key switch was replaced under recall around 5 years ago.
Question I have is, what powers/sends the voltage to the switch to operate that can cause this (and power and light should operate separately, right)?
Tks much in advance...
bp

 

The courtesy lights are supposed to dim out in a few minutes after the driver door is closed.

Fuse #21 is for the outside mirror switch. No relay involved. The light is on a different circuit fuse #27 on the BCM and a non accessible relay.
Maybe you got a couple of wires crossed on the new switch? Maybe they changed pin positions on the connector. The gray is for the light, red/wht is for the switch.
Maybe your dimmer switch got turned to the far left "on" position?

 

Yes double check the dimmer switch

 

Thanks much for replies!
fyi...I did already check the dash light dimmer switch, it had no effect. I kinda lean to the "new" switch being bad "internally" as plug looks fine (I already ordered a new one).
But what throws me is the mirror switch "still" has power with key off and out, all doors shut and after the light delay shuts all lights down.
I don't think it should have power with key out. It only loses power when the 5 amp fuse is pulled.
I will post fix if I can figure it out!

 

The switch should have power always, the light only with key on. A wire must be crossed internally or externally. They are on separate circuits with a common ground, so maybe the polarity is backwards.

 

Hmm. My mirror switch has power all the time.(key in, key out) Pretty sure that's how it's designed. It won't draw any power unless you are using it and adjusting the mirrors.
Now, the accent light on the switch staying on .........that's from another circuit. Or should be.

 

Do both mirrors work perfectly with the new switch?

I recently had trouble with the mirror switch; a few of the contacts were bad so I removed it for replacement.

I then discovered I could take the switch apart and clean the contacts.

It's not impossible that the new switch is defective. You could try re-installing the old switch, with or with fixing it first.

While you're at it, look for damage to the wires from yanking them around during r&r.