Ground to frame vs. body? Is this the same thing?

[882993md]

Hi everyone,

I see that some people refer to grounding to the frame/chassis. Then I see some refer to ground to the body/firewall.

 

If the engine and trans or both are grounded to the frame, would one still need to ground to the body (shock tower, firewall)?

 

Finally is 8 gauge insulated wire sufficient, or are the braided grounds straps better?

 

Howard

1974 260z

Edited January 23, 2017 by 882993md

[Zed Head]

Actually, in a Z car, the frame and body are essentially the same thing.  There are "sub-frame" components, that look like a typical frame but are actually welded or bolted directly to the body.  On a typical frame-based car the body is sitting on rubber bushings on top of the frame.  

If you just confirm that what Nissan installed is intact you'll probably be fine. Many of the ground circuits are redundant.  The engine is grounded to the battery through the negative battery cable but there are other ground wires, probably to ensure that paint, gaskets, or thread sealer aren't interrupting a circuit.  You can check ground circuits using a test light or a meter.  A meter will give you more information. 

[nix240z]

10 gauge is the wire size that was used on the original - battery cable for the firewall ground. 

[sweatybetty]

you need a ground from the battery to the engine block, and one from the engine block to the body/frame. 8 gauge will work well, but make sure all connections are clean and tight.

i would be willing to bet 85-90% of all electrical problems are loose connections/bad grounds

[882993md]

Thank you for the replies and information.

Howard

[240260280]

Electrons are lazy and always take the shortest path of least resistance home.