Due to the way GM decided to do the control of the heaters in the seats. It's what's called bang-bang control. The control system turns on the seat heaters and when the desired temp is reached, turns it off. This is very hard on the heaters. Bet you'll find the seat side of the heater open. Best solution, I believe, is to replace with an aftermarket seat heater.
Do you have dual control thermostats?
behind fusebox drivers side
On the upper left side of the drivers side floor pan.
To replace the drivers side mirror on a 1966 Impala, remove the screws with a Philips head screwdriver. Remove the mirror , there will 2 5/16" bolts retaining the baseplate.
On the drivers side in front of the rear wheel.
Drivers side, above the kick panel vent
the egr valve on a 2004 impala should be on the drivers side of the engine. It is located at the rear towards the firewall.
drivers side valve cover, towards the back
look on the drivers side door at the specifications tag.
it is located under the rear door, drivers side
Look on the drivers side door at the specs decal.
look under the front fender under the hood on the drivers side.