Electrical Issues - 2007 Silverado LTZ

[MeatEater23]

All,

I am new here and I just wanted to thank the community for always being helpful in the past. I have relied on multiple posts to rectify issues I've had with my Silverado but the issues I am currently having, have me stumped, and are costing me an arm and a leg.

My Truck - 2007 Chevy Silverado 1500 (NBS) LTZ 5.3 - Bone Stock - No LED's anywhere or after market radio

What is currently happening:

• Whenever I am in cruise control and use my turn signal, it sometimes cancels my cruise and I can see the dash light flicker.
• Even the use of turn signals make the dash light flicker (This is observed when voltage is at 14 or below)
• The dash light also flickers sometimes when I press the brakes. Occasionally I will also hear the radio pop
• When I turn the truck off the radio sometimes makes a pop noise like killing the motor is surging or shorting something (The radio should remain on via Retained Accessory Power) and the dash light flickers as well

What I have tried

• Cleaned both battery terminals and cable ends
• Cleaned A frame ground to bare metal
• Cleaned all ground ends coming off of the negative battery cable
• Ran an additional ground from firewall to below alternator framing for a ground point (Saw this via a YouTube video)
• Confirmed firewall to engine cylinder head ground is still strong and not corroded
• Took it into a GM dealership and had them look over everything and update all computer modules (only update that was performed was a radio update)
• Battery was swapped in November of 2022
• Alternator was tested
• Confirmed fuse box under hood was free of corrosion and has good contact

I am at a complete and total loss. Please help.

Thank you all!

Edited September 8, 2023 by MeatEater23

[richard wysong]

Sure sounds like a ground issue probably in the dash. Have you checked for body codes? Best to get a wiring diagram and see if the cruise and the lights/radio share a ground. Also could be BCM problem

[MeatEater23]

Richard, thanks for the reply!

Yea I tried all of the major grounds to the body and such but have not been able to locate any in the dash, any idea where they might be?

 

I had a GM tech hook it up to a tech 2 and check for all codes and such and absolutely nothing stood out to him. This has managed to stump multiple shops and its getting very costly to say the least.

[richard wysong]

I'm not sure but possibly behind the kick panels and maybe to the right of the steering column. I assume you have checked the light sockets for  power and grounds and the correct bulbs

Edited September 8, 2023 by richard wysong

[MeatEater23]

I'm currently digging for diagrams but don't have too much experience in reading them. Let's hope I can find something like you stated. Your advice is very much appreciated!

These issues have been troubling me for years, not these exact issues but various electrical issues nonetheless. 

[MeatEater23]

Hopefully some other members have some ideas of these ground locations or point me in the right direction. 

I have been to 3 chevrolet dealerships and have spoken to upwards of 15 of them and most service advisors don't really have a clue what it could be without looking at it.

One said perhaps its the brake switch, one said its probably the ground from firewall to engine and another said potentially the bcm. The thing is, these issues don't always happen but they've been happening much more frequently. 

[swathdiver]

I had something similar happen on a trip once.  Every time I used the turn signal the cruise control would drop off.  Turned out to be a loose positive battery cable.  

 

You may not see corrosion on the terminal ends of your 17 year old car but I bet they are corroded internally.

 

An otherwise good battery could have a bad cell which are notorious for creating electrical gremlins that are tough to track down.  

[MeatEater23]

Swathdiver,

Thank you for the response! I had a tech think it was the positive cable end since they're soft lead so as it sits, the red plastic sleeve has been removed and the terminal has a mini shim in there and that cable is very snug. I thought about cutting and putting a new end on there but multiple technicians said it should be totally fine with that shim since there is zero play. 

[swathdiver]

43 minutes ago, MeatEater23 said:

Swathdiver,

Thank you for the response! I had a tech think it was the positive cable end since they're soft lead so as it sits, the red plastic sleeve has been removed and the terminal has a mini shim in there and that cable is very snug. I thought about cutting and putting a new end on there but multiple technicians said it should be totally fine with that shim since there is zero play. 

Well, I have seen those posts not connect well internally and I then suspect your positive cable being internally corroded.  

[MeatEater23]

Cable appears to be in awesome condition with no visible corrosion but that surely could be. There is enough slack in the cable that I could cut the end and terminate a new end on. 

I am leaning more towards an issue with the brakes or turn signals and/or a ground for those very components but I'm not mechanic. 

[MeatEater23]

I should mention that two weeks ago I had a flashing airbag light on my dash, my mirror compass and thermostat display was freaking out and my radio was cutting in and out. Not sure if this helps any. That only happened once though.

[newdude]

How does the underhood fuse block look?  Any corrosion in the top?  How about underneath, so remove the box from its mounting, all the pins clean or is there corrosion?  The underhood fuse boxes are very common on the 2007-2013 generation trucks for causing all sorts of issues.  Lots of the time its the internal PCB that is faulted or corroded, or its the pins in the bottom.   

Edited September 8, 2023 by newdude

[MeatEater23]

The GM tech tested each pin and said everything looked stellar, practically brand new.

[MeatEater23]

@richard wysong, I assume you have checked the light sockets for  power and grounds and the correct bulbs.

In the 6 years I have owned the truck I have only ever had to put in headlights and I have always gone with the Sylvania H11's. I had my fiancé in the truck and toggled all lights on and confirmed every single bulb works and illuminates. 

[MeatEater23]

Still cannot find or confirm where the grounds are for the headlights.