03 Silverado - 3rd Brake Stuck on, no Dome Light - Truck Forums

Go Back  Truck Forums > Full Size Truck Forums > Chevy Silverado/ GMC Sierra Forum
Reload this Page >

03 Silverado - 3rd Brake Stuck on, no Dome Light

Chevy Silverado/ GMC Sierra Forum Discuss the Chevrolet Silverado and GMC Sierra here.
Sponsored by:
Sponsored by:

03 Silverado - 3rd Brake Stuck on, no Dome Light

Reply

 
 
 
  #1  
Old 04-08-2018, 10:50 PM
Beginner
Thread Starter
Join Date: Apr 2018
Posts: 1
Question 03 Silverado - 3rd Brake Stuck on, no Dome Light

My name is Randy and I am Uber Man on YouTube. I buy wrecks to rebuild for my channel. I usually have no issue diagnosing electrical but this one has me stumped and I just know these issues are related. I have a 2003 Silverado 2WD, 4.3L, Reg Cab, SWB w/ factory tow package. I have four issues that I believe are related as follows:

The 3rd (CHML) brake light is stuck on unless the truck is not running. If the truck is running the 3rd brake light will remain on. The normal brake lights function properly. When I pulled the CHML fuse, the 3rd brake light remained on. When I pulled IGN 3 fuse, the 3rd light shut off. When I unplug the BROWN plug from the I/P fuse block, the 3rd brake light goes off.
The cargo light does not function at all. When I push the button for the cargo light a yellow dash light comes on showing the light is on. Both bulbs are good. Wiring appears to be fine as well.
The dome light will not work unless I directly wire a ground to it (from the blue wire to the frame. It appears the black wire is 12v+) With a ground connected the dome light comes on BUT it will not turn off. Even with the doors closed, the dome override switch pressed, it remains on unless I disconnect my test wire.
The rear view mirror has an airbag on/off light. This light does not work at all. The light on the override switch does work properly.

I feel that all of these issues are probably related to the brown plug on the I/P fuse box. Maybe they are not related at all. This is beyond my capabilities. There are no codes, and everything on the truck functions properly except these aforementioned items. This truck has no options other than A/C and cruise control.

I have pulled the headliner, pulled the A pillar trim on the driver side, torn the dash apart, pulled the sill covers on the driver side. I can not find any damage to wiring anywhere.

It may be worth mentioning that there was an aftermarket stereo / amp / subs installed at some point. (It was back to factory when I got it but the old wiring was left behind and not done well) I have not removed the radio but the factory stereo always says "CAL ERROR" and will not remember stations, or settings other than time.

Please, help.

Thank you,

Randy Shear
 

Last edited by Randy Lee Shear; 04-08-2018 at 10:53 PM.
Reply With Quote
  #2  
Old 04-14-2018, 09:40 PM
NullHead's Avatar
TruckForum Addict
Join Date: Apr 2011
Location: Detroit, MI
Posts: 1,227
Default

Hi Randy, I have been reviewing your problems listed in your post. I also have watched your video on youtube where you talk about your issues with this truck. I have a few questions that may clear things up for you. I should explain that I am a GM dealer technician and decided to chime in and help out because your issue peeked me interest. I'm an electrical aficionado and love to tackle problems like this.

My first question is when you say you unplugged the "brown connector" - is that on the passenger or driver side IP fuse panel? Both of these fuel panels contain brown connectors and it will make a difference as to where we go from here.
Second: Do the HVAC functions work okay? All blower motor speeds, actuators for defrost/vent/floor?

Also if you would, please clarify your voltage readings on your cargo lamp socket for me. Your "blue wire" should actually be "grey w/black stripe" which I can see being easily confused. The solid black wire here should read straight ground. Literally read 0.0v on your DVOM. If it reads anything close to battery voltage, your issue lies with voltage backfeeding through your right side IP fuse panel and quite possibly related to ground g200. I cannot help you specifically as to where this ground is, but the description in the service manual says "In the HVAC Harness, on the Right Side of the I/P Near the A-Pillar Below the I/P Top Cover"

The next peculiar thing I see is that you mention the "IGN3" fuse. From what I can tell, this fuse should only be installed in your fuse block if your truck is equipped with RPO code "NYS" - in other words if you have a rear steer truck. Based on your video I do not see this to be the case so perhaps IGN3 fuse should be eliminated at this point to help clear some diagnosis up.
 
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
k4apy
Chevy Silverado/ GMC Sierra Forum
0
10-30-2017 08:23 AM
cycleman
Chevy Silverado/ GMC Sierra Forum
1
03-07-2012 07:20 PM
FWC Preddy
Chevy Silverado/ GMC Sierra Forum
3
07-11-2010 02:09 PM
dmccartyfan
Chevy Silverado/ GMC Sierra Forum
6
06-16-2010 07:38 PM
chiefmike
General Motors Tech
0
02-28-2008 05:31 PM


Thread Tools
Search this Thread
Quick Reply: 03 Silverado - 3rd Brake Stuck on, no Dome Light


Featured Sponsors
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.