Chrysler Repair: Power Seats and Infinity Amplifier 1989 New Yorker, yorker landau, infinity radio

Question
Hi - I am the original owner of an 1989 New Yorker landau with 80,000 original miles.

Recently, many of the electrical items have gone out and I have been busy at the wrecking yard.

I had to replace both front window motors, the signal/stop light control module and light harnesses and other electrical problems.

Now, my drivers side power seat control is not working, but, the seat memory continues to work so that I know that the motor works.  I have replaced the drivers side seat control unit with others that work on the passenger side but do not work on the drivers side.  There is no electrical current jump or flicker when I depress any of the buttons so I do not think that any current is passing from the control unit to the seat motor.  Is there a module that controls power seat signals?

My second question deals with the Infinity radio system.  I only have the two small dash speakers working.  The door and rear speakers do not work.  I replaced my current radio with another and the results were the same.  My guess is that thre is a second amplifier under the dash somewhere that is malfunctioning.  Do you know the location>  

Answer
The power seat problem sounds like a ground issue. The switches operate like the window switches, in one position, the pos. is on the left pin, in the other pos, it;s on the right. Since there is no dimming of the domelight, it must be the ground. Using a test light, hold the motor button down and test the leads on both sides of the motor. If both sides light up, start tracing the ground wire back and repair the fault to body connection.

For the radio, as far as I know, there is no secondary amp. Drop in to autozone or parts source and ask for the wiring diagrams for your sound system. They usually will print it out for you for free.