[ProblemCar]

Does anyone have a pic or good description of where on the chassis, the ground from the engine block is bolted? I have seen a wire bolted onto the engine block (just below the left/driver-side valve rocker arm cover - facing the rear, inside the dog house). That wire goes into a large 2" or 3" diameter harness/conduit, but I cannot see where the other end comes out of the harness and bolts onto the chassis. I have a 2003 Astro. Thank you.

 

[AstroWill]

Have you heard about the GM Techline eSI(links in sig)? It has exactly what you are looking for.
https://goo.gl/n8dJkS

 

[ProblemCar]

I have the "SI DVD 2008.03 Last updated September 29, 2008" but the pics and drawings are pretty bad. The ground schematics do not mention the location of the grounds, but merely gives the codes for the grounds. Eg. the ground I was describing is merely labeled G107, G106 (there are two wires from the harness into that location next to the knock sensor). From the schematic, it seems like other components are terminated to ground there, and it's not where the engine block from there to another ground on the chassis. Perhaps I just have a bad version of the software. Thanks for the links though. Maybe I'll download again to see if it's different from mine.

 

[AstroWill]

NP, check:
Body>Wiring Systems>Component Locator>Master Electrical Component List

g100 201

• AstroWill
• Sep 11, 2017

 

[chevymaher]

I used the metal straps from a chevelle since I had a bunch of extras. Block to frame. Frame to body. Way better than the little wienie factory grounds in the wiring harness.

Doesn't matter where they were problem solved. Welder conductivity.

As for the actual question. They varied. I found 3 nobody knew were there. Not on the diagrams not in the collective knowledge. Just where ever the guy working that day felt like putting them.

Good example is the fuel pump ground on mine is actually under the drivers seat by the fuel filter. Sticks out of the wiring harness and bolts right to the floor. I cleaned the paint off bolted it back down and painted over it.

Just got to look and get intimate with your particular vehicle.

 

[ProblemCar]

Thank you AstroWill. Half the time I look at the diagrams in my eSI and I still can't figure it out because it's out of context, showing only a small part of the engine bay. But I think I finally figured out: on the 2003 there's one ground the bottom front side of the engine, in front of the starter, connecting directly to the negative end of the battery and/or the ground above the headlight in front of the battery. (But, in case future readers happen on this - I haven't crawled under to check just yet.)

As for getting intimate with my vehicle, alas no time, and I wasn't supposed to be married to it for 14 years!

 

[ScottieDucati]

 

[OldSchoolNoe]

Ah, my guide seems to have helped a few people! I know what OP means. If components are grounding to G106 and G107 on the engine block, then where is the engine block grounding to on the chassis?

The answer is G103 , it runs from the engine block straight to the negative battery terminal, screw a chassis connection!