GMC Envoy Negative Battery Cable Replacement

My 2007 GMC Envoy is getting a little old.  I’m having some electrical issues that may be caused by bad grounds.  I came to this conclusion by doing some internet research and inspecting the negative battery cable.  The ground connections were all corroded and green; this prompted me to purchase a new negative battery cable.

The below post is how you would change this out.  I wouldn’t normally post on how to change out a battery cable, but there are multiple points of contact and it is not as straight forward as you would think.  It’s not hard, but there is a little to it.

Remove the Electrical connector from the negative battery terminal.  This has a slide clip on it, so you will need to slide the grey part of the clip back and then push down on the release lever.

Negative Battery Cable Electrical Connector

Use an 8mm socket or wrench to remove the negative battery terminal from the battery.

Remove the 10mm bolt that is holding the ground closest to the battery.

Now comes the tedious part of the job.  There are two other grounding points for the negative battery cable, and you will need to undo some of the wire loom that is bundling the wires together.  This is easily accomplished with a utility knife or scissors if you don’t have a knife.  Just be careful not to cut any of the other electrical lines.

Jack up the truck and remove the driver’s side tire.  You may be able to accomplish this with the tire on, but it only takes a few minutes to remove it and it makes the job that much easier.  Make sure to use jack stands for safety!

Remove the 10mm bolt that is grounding the cable to the frame.  This is located behind the front driver’s side tire on the side of the frame. 

Now you will need to remove the Engine ground, this is the last bolt that needs to be removed and is also the hardest to get to.  This bolt is the reason to remove the tire!

The 15mm bolt is located on the bottom of the engine.  I needed to attach a socket extension as well as a breaker bar to loosen the bolt.  Once it was loosened, I attached a regular ratchet to it and removed.  There are a lot of miscellaneous lines in the way so it took a little bit to remove it.

Once this is removed, you will need to pull out the old wire. 

There is a plastic clip located above the frame ground on the body where the shock mount indent is. 

There is also another one up by the battery terminal.

Be careful not to just rip these off, you will want to be able to use these when re-routing the new cable.

I pulled the cable up from the bottom, releasing the bottom clip first, and then using the utility knife to cut the electrical tape to remove it.  Once the electrical tape was removed, I opened the plastic wire loom and removed the cable completely.

I used some 80 grit sandpaper from the Porsche project to remove the paint and corrosion around the ground connections.  I did the body ground connection and the one on the frame.  I made sure that where the connection was it was down to shiny metal.

To re-install the new cable, fish the bottom end from the battery area down through the same route you just pulled the old one from.  When that is complete, start connecting the grounds starting with the engine ground first, then the frame, and up to the battery terminal.

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