Aftermarket radio install problems
atlasate
04-09-2008, 02:26 AM
I am posting this question again since the previous thread (over 2 years ago) did not answer it.
I have a 1996 olds LSS and after installing a aftermarket radio I found that the steering wheel controls did not work, nor would the AC/heating display dim at night or respond to the instrument panel dimmer control.
Curious about this, I looked up the wiring diagrams for my car at alldata and found out the following:
The steering wheel controls are converted from an analog to a digital output in the original factory radio. Quote: "The steering wheel switches are actually a ladder network consisting of the switches and a series of resistors. This ladder network is constructed so that each switch has a different resistance. This arrangement supplies a different voltage output to the radio for each of the switches, when pressed. The radio converts the different HVAC switch selections to serial digital data messages, which are then broadcast to the HVAC system over the E&C serial data link." The schematics/wiring diagram confirmed this.
For the dimmer problem, I tried to jumper the display dim signal input to the radio directly to the display dim signal output (a straight 12V connection, as far as I could tell, looking at the radio wiring). This didn't work. I found out looking at the lamp dimming wiring later that the radio has a variable dimming circuit built into it ($@%! GM!).
So now what I need to know is there an aftermarket device available that duplicates the missing circuitry in the radio. I have looked online but I can only find devices that cover newer GM vehicles with Onstar systems. I will keep looking and if I find anything I will let you know but I figured others have had this problem and may be able to point me in the right direction.
I have a 1996 olds LSS and after installing a aftermarket radio I found that the steering wheel controls did not work, nor would the AC/heating display dim at night or respond to the instrument panel dimmer control.
Curious about this, I looked up the wiring diagrams for my car at alldata and found out the following:
The steering wheel controls are converted from an analog to a digital output in the original factory radio. Quote: "The steering wheel switches are actually a ladder network consisting of the switches and a series of resistors. This ladder network is constructed so that each switch has a different resistance. This arrangement supplies a different voltage output to the radio for each of the switches, when pressed. The radio converts the different HVAC switch selections to serial digital data messages, which are then broadcast to the HVAC system over the E&C serial data link." The schematics/wiring diagram confirmed this.
For the dimmer problem, I tried to jumper the display dim signal input to the radio directly to the display dim signal output (a straight 12V connection, as far as I could tell, looking at the radio wiring). This didn't work. I found out looking at the lamp dimming wiring later that the radio has a variable dimming circuit built into it ($@%! GM!).
So now what I need to know is there an aftermarket device available that duplicates the missing circuitry in the radio. I have looked online but I can only find devices that cover newer GM vehicles with Onstar systems. I will keep looking and if I find anything I will let you know but I figured others have had this problem and may be able to point me in the right direction.
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