Mirrors, heat/dimming
I have an '07 Sierra, and am not familiar with the '03s .... SO, I may be talking out of the back of my front here... but anyhow...
I am assuming you have the mirrors that more/less look like automotive mirrors, i.e. NOT the monstor trailer tow mirrors that are available now.
My '07 has only a driver's side dimming mirror only. I have the heated mirrors as well. They are BOTH heated.
I assume that the passenger side is supposed to heat, but, by design, does not have the auto dimming function.
I doubt it, but are the left and right mirrors fused
seperatly with respect to the heating function? If so, maybe simply a fuse.
Otherwise, it appears that the heating element in the RHS mirror may be out.
I know this is all supposition as I have an '07, but usually, GENERAL functionality remains pretty congruent over time.
IF the heating element in the mirror is out, I highly assume the only option is to replace the entire assembly.. any
Chevy OEM part from a dealer will not be a bargain.
On the other hand, I have seen ads from accessory houses in auto magazines that sell heated/LED turn signal mirrors, aftermarket, that look VERY MUCH like what is on my truck. Maybe worth a call to one of them to see if you can get a one-off piece. For a
Chevy Mirror try
www.gmpartsclub.com
If you have the owner's manual, it should, at least, tell you if the passenger side mirror is supposed to heat... as said, on my '07, it DOES heat up via a switch on the HVAC control panel.
I know this may not help MUCH, but I hope it does a little.