Headlight Switch "Off" Position

[snomuncher]

I'm looking into some possible lighting modifications on my 2005 SSR, and would like to know if 2003 or 2004 headlight switches can be turned to the "Off" position. On the 2005, although there is an "Off" indicator on the bezel, the switch cannot be turned past the "Auto" position. It's appears to be a four-position indicator (off, auto, park and on) with a three-position switch (auto, park and on).

Thanks in advance.

[Mike in AZ]

This was discussed in depth a few months ago. here's the thread.....

daytime running lights

My factory manuals have helped a lot...


Hope this helps,

Mike

[snomuncher]

Hello Mike:

Thanks for the vector to an earlier thread on DRLs and auto headlights. I agree that the easiest obvious solution to disabling the DRLs is to remove the fuse, as suggested. But no one really solved the “bypass of the auto headlight feature” question in that thread.

I’ve studied a lot of Helm service manuals for my various GM vehicles over the years and made many electrical modifications and improvements, always careful not to disrupt the BCM, PCM, or other control functions. I believe the solution to disabling the auto headlights (“twilight sensor”) may lie in inserting a resistor into the auto headlamp light sensor circuit to “fool” the BCM into thinking that it is daylight all the time. This has been done by other Chevy full-size truck owners up to model year 2002. It has been proven on other GM truck sites that cutting the sensor wires does not work. In fact, doing this creates an “infinite” resistance and an open circuit that is interpreted by the BCM as darkness so the headlights stay on all the time. Finding a resistor of the correct value that works on the SSR will require me to do a little more research. I’m going to compare some of the wiring diagrams and operational features of auto headlights from my Silverado, EXT and SSR manuals for similarity. There were significant wiring changes starting in 2003 and I want to address the condition associated with lights coming on after the wipers are on for 35 seconds as well. At best I will conclude that I can use the resistor solution that has worked for other GM full-size truck folks. It’s really not very intrusive and just requires installing the resistor in series with one of the sensor lead wires. At worst, there may be a more complex solution yet to be developed.

Once a solution is in place, I believe I will have a headlight switch that operates with no lights on in the “Auto” position, parking, tail and side marker lights on in the “Park” position, and headlights, tail and side marker lights on in the “Headlight” position.

This modification is but one I’m planning for improved lighting (adding footwell lights and an underhood light are others) but I won’t tackle them until I develop an integrated solution.

[Mike in AZ]

I had looked at this circuitry as well and spent some time analyzing the theory of operation.... Good choice on your part to find a solution that adds to the system and doesn't just disable everything. If you want to have a second electrical/electronic pair of eyes for an analytical review, please feel free to contact me via PM. I'll dust off my old knowledge and help all I can.

Regards,

Mike