Ground G104 5.7... What is it for?

[KCusick81]

Good afternoon everyone,

I replaced/upgraded the ground straps from the passengers side rear of the engine block to the frame and the frame to the firewall. During tightening of the nut on the ground stud on the back of the head, the other ground that is connected to the same stud ,broke because of the damn star washer. Anyway, the truck starts, seems to run fine and isn't throwing any codes. After scouring the internet, I'm fairly sure that the ground that broke is G104. However, I cannot for the life of me find any info on what it's for. Anyone know?

Truck is 1997 Chevy K1500 5.7

Thanks in advance.

 

[0xDEADBEEF]

Don't know, but I would just crimp (or solder, LOL) on a ring terminal and re-attach it and move on with life.

 

[1998_K1500_Sub]

I'm fairly sure that the ground that broke is G104. However, I cannot for the life of me find any info on what it's for. Anyone know?

The 1998 service manual tells me this:

G104(Gas, Diesel)
RH top center of Cylinder Head
See the attached image, which is the ONLY image I found in the service manual that illustrates the location of G104 (yes, it shows a 7.4L and yours is a 5.7L, what can I say, I didn't author the manual I'm just posting it here).

G104 is used as ground for multiple circuits, e.g.,

- cruise control

- DLC connector

- HVAC compressor control (grounds compressor control logic)

- audio alarm (the buzzer for seat belt / headlights / etc.)

- gauge cluster (fuel gauge, high-beam indicator, cluster illumination, etc.)

- security system ("This circuit supplies ground to the SECURITY indicator at the Instrument Cluster from the Passlock ™ Module, circuit 749."

This is not meant to be an exhaustive list. It's what I found using a quick search of the manual's .pdf.

You must be registered for see images attach

 

[1998_K1500_Sub]

Here's a list of most (if not all) grounds on the engine, from the 1998 service manual:.

You must be registered for see images attach

 

[1998_K1500_Sub]

FYI, attached are images I found in the manual showing the rear of the 5.0 & 5.7 engines, and the rear of the 4.3 engine, along with some of the wiring. Not all of the wiring is labelled. Maybe you can locate, visually, the ground you mentioned.

Don't assume these illustrations are correct. The manuals are not perfect.

 

[someotherguy]

Thing you have to remember is the power will do its best to find a ground. That doesn't mean the ground path it finds is a good one. Fix your broken ground would be the best course of action before you discover the hard way where it decided to ground instead.

Richard