Attention: TDR Forum Junkies 
SnoKing
TDR MEMBER
I want to start out by saying I am having a new love affair with my 2001.5 RAM! I recently had to rebuild the transmission at 110K even though I had a custom DTT transmission built in 2004 at 30K on the clock.
So with a fresh new transmission and a new triple disc torque converter I have been doing other maintenance chores on it. Servicing the diffs, adjusted the valves, removed the seats and installed some sound deading under the carpet, repainted the diffs black etc.
So today I tackled the heated mirrors that quit working a couple of years ago. Little back ground here! I was trained in the USCG as a electronics tech in 1965, worked at NCR as a field engineer on electronic equipment, and finished my working years as a network design engineer at BofA/EDS.
So I snapped the dash surround off and remove the four screws that hold AC/Heater/Mirror switch unit into the dash. There are three wiring harnesses that attach to it and a bundle of vacuum lines. The bottom small plug is the heated mirror connection. I checked for 12V with the key on at the Blue wire using the Bk/Or wire as ground. I found that there was 12V DC to the heated mirror switch. This is really a lot more than a simple switch. There is a relay and timer circuit also.
Looking at the whole unit there were three small bright screws and three tabs that held the black cover on the back of the lower section. I disconnected the three electrical plugs and then I removed the three screw and used my knife to pry the three areas of the black cover off the white tabs. What I saw inside was a small circuit board with the relay, a timer chip, some diodes, resistors and one capacitor. There is a white wheel that overlaps the circuit card which is the back end of the temperature control. I pulled on this wheel enough sliding it back to be able to remove the circuit card.
So you check the simple things first, right! Physical inspection showed no burnt up components, which was the first good sign. Relay or push button?? So I set my meter to beep on a closed circuit and touched the leads to the back of the circuit card mounted push button switch legs, and pushed the button!!!! No beep! I took a can of contact cleaner and flooded the switch a couple three times down the side of the little button. And cycled it a bunch. Hooking the meter up again I then got a beep when the button was pushed. Yeah Team Chris!
Putting it carefully all back together, I now again have working heated mirrors. If it acts up again I will replace the circuit card mounted little push button switch. Bank account is 178+ bucks to the good, as they only sell the complete unit. I was having to much fun to slow down and take pictures and it was a bit dark in the truck inside the garage. If I take it apart again, I will take pictures, I promise!
Chris
So with a fresh new transmission and a new triple disc torque converter I have been doing other maintenance chores on it. Servicing the diffs, adjusted the valves, removed the seats and installed some sound deading under the carpet, repainted the diffs black etc.
So today I tackled the heated mirrors that quit working a couple of years ago. Little back ground here! I was trained in the USCG as a electronics tech in 1965, worked at NCR as a field engineer on electronic equipment, and finished my working years as a network design engineer at BofA/EDS.
So I snapped the dash surround off and remove the four screws that hold AC/Heater/Mirror switch unit into the dash. There are three wiring harnesses that attach to it and a bundle of vacuum lines. The bottom small plug is the heated mirror connection. I checked for 12V with the key on at the Blue wire using the Bk/Or wire as ground. I found that there was 12V DC to the heated mirror switch. This is really a lot more than a simple switch. There is a relay and timer circuit also.
Looking at the whole unit there were three small bright screws and three tabs that held the black cover on the back of the lower section. I disconnected the three electrical plugs and then I removed the three screw and used my knife to pry the three areas of the black cover off the white tabs. What I saw inside was a small circuit board with the relay, a timer chip, some diodes, resistors and one capacitor. There is a white wheel that overlaps the circuit card which is the back end of the temperature control. I pulled on this wheel enough sliding it back to be able to remove the circuit card.
So you check the simple things first, right! Physical inspection showed no burnt up components, which was the first good sign. Relay or push button?? So I set my meter to beep on a closed circuit and touched the leads to the back of the circuit card mounted push button switch legs, and pushed the button!!!! No beep! I took a can of contact cleaner and flooded the switch a couple three times down the side of the little button. And cycled it a bunch. Hooking the meter up again I then got a beep when the button was pushed. Yeah Team Chris!
Putting it carefully all back together, I now again have working heated mirrors. If it acts up again I will replace the circuit card mounted little push button switch. Bank account is 178+ bucks to the good, as they only sell the complete unit. I was having to much fun to slow down and take pictures and it was a bit dark in the truck inside the garage. If I take it apart again, I will take pictures, I promise!
Chris
