can't manually turn park lights on

[extrabigjon]

When I manually turn the dash knob to park, the truck and trailer running lights will not come on. It acts as if that setting does nothing. If I leave it in auto everything works fine. The manual headlight setting turns everything on as well. Both key fobs can make the park lights flash. All turn signals and headlights are incandescent and function normally. I swapped my dash switch with another known good one and that did not fix it. My switch worked fine in the other truck though. Reseated the connector a few times and jiggled the harness. Swapped the park relay for the starter one and nothing changed, truck still started so the relay is good. On the park relay if I jump pin 87 to 30 I can manually turn on the park lights for the truck and trailer plug.

 

Basically the dash knob in the park setting does nothing. Even with they keys removed the door chime will not sound to remind you they are on.

[swathdiver]

It would be nice to get in there with a Tech2 and see what's going on and if there are any internal BCM codes.  Could be your BCM but maybe not.

[pat_this]

This might work as a replacement

 

https://www.ebay.com/itm/Headlight-Dome-Light-Dimmer-Switch-for-Chevy-GMC-Cadillac-Hummer-Brand-New/311973672631

[extrabigjon]

 

1 hour ago, pat_this said:

This might work as a replacement

 

https://www.ebay.com/itm/Headlight-Dome-Light-Dimmer-Switch-for-Chevy-GMC-Cadillac-Hummer-Brand-New/311973672631

My switch tested good.

On 8/22/2018 at 12:29 AM, extrabigjon said:

I swapped my dash switch with another known good one and that did not fix it. My switch worked fine in the other truck though.

 

[Ak_grown]

aftermarket remote start installed? test a grey black wire coming off the light switch for parking lights. it would be neg.(-) signal. 

 

Parking Lights+ brown   +   driver kick panel

 

Parking Lights- gray/black   -   BCM, brown plug, pin B2

 

Notes: The BCM (Body Control Module) is under the driver side dash. It has 6 plugs in it, the purple plug is on the back.

 

Hazards white   -   steering column, 5 pin plug

[extrabigjon]

Yes I have an aftermarket remote start installed. Sorry, I'm not following the rest of your post