^ Agreed, misinformation in a thread that people will refer to is not a good thing.
Landlocked93 clearly doesn't understand the distinction between a poor ground path and an ENGINEERED one by Toyota etc. He doesent understand how the body mounts to the frame and at what places there's a possibility of an electrical path from the frame to the body.
Ok...
...at the very least consider brake lines with metal terminations - OEM or stainless braid- which connect the body to the frame in a metallic fashion. (OEM may be rubber on the outside but there is metal belting inside the rubber)
Beyond that, consider the springs which simultaneously contact the body and the axles.
Or perhaps the driveline itself...from engine to axle...yes there are rubber bushings on all the moving parts but the metal collars inside the bushings through which the bolts are positioned enable a ground between the engine and the frame via the frame/axle ears, again through which the bolts connect.
Ground loops impact more than just audio. One just can't hear it, is all.
So, there's some gems here. I haven't cut a toyota oem brake hose, but rubber brake hoses are made of layers of rubber and various fibers, I've not seen metal belting. He also seems to think that the brake lines electrically couple the frame to the body - if that was actually the case, then I'd hate to rely on that path to carry 10's of amps! The brake lines make physical contact between the brake pipes (the hardlines) and the ABS/Brake cylinder assembly and some of that touches the body on the firewall. There's no body/frame connection to brake lines at the axle ends.
Regardless, the next gems are due to not understanding the chassis/body mounting system.
The 80 springs (coils) do NOT make simultaneous contact to the body - the spring mounts at the bottom are on the axles, the spring mounts on the top are to the frame , NOT the body.
"... the moving parts have rubber but metal collars inside that bolts are positioned enable a ground..." Huh??? There is NO electrical contact from the metal bushing in the rubber control arm bushings to the links. The bolts touch the metal inner sleeves and the chassis end and axle end. There is no electrical path through the rubber. Body mounts are designed the same. Engine/transmission/transfer box mounts are all metal bonded to rubber bonded to metal, same with exhaust mounts. There is no electrical path through them.
The whole point (clearly missed) is that the body (and engine/transmission etc) are mounted on rubber with no electrical path through those mounts.
I'm pretty sure that the only electrical path from the chassis to the engine block AND body is via the tailshaft bearings and any damaged bushings. Maybe the handbrake cable too. The axles may make electrical contact (very poor contact given they are also coated when new) to the frame via the coils. Shocks (OEM) have rubber bushings and are electrically isolated. On the rear the top coils have rubber 'pads' to provide some NVH isolation, so the path is even worse.
There is a good reason to not do as landlocked93 has recommended.
1) if the body is a great ground path (and it is) and you now have grounded your device to a bolt. Is that a through a hole that has been drilled or a Toyota captive (welded) nut to the body? If a Toyota captive nut as described, then you have an excellent ground path and your job is done.
2) Now if it was a drilled hole with a bolt and you put a ground strap/cable connection from the other end of the bolt (that you drilled a hole) to the frame. Consider now having a poor contact through the drilled body, you now have a ground path that mostly only goes to the frame. As per above, the frame to body ground path (and we're really talking frame to block) is very poor and mostly through the bearings in the tailshafts. Not a good idea eh?
Anyhow, hopefully there's enough rebutal to his recommendation that folk reading this thread will have a better understanding why the frame is not an appropriate ground path. What he has done on his vehicle works because the body is providing the ground path. Adding a connection to the frame provides no benefits when the body path is perfect and provides intermittent (or worse) problems when it isn't.
He also stated grounds are all the same, series, parallel etc. Wrong in so many ways, that it's not worth discussing.
Finally, Toyota does NOT use the frame as an electrical ground path. Their EE folk didn't miss the frame being made of steel, they understood perfectly well to use the body as the ground path for all non-engine ground connections because the frame is mostly electrically isolated from the body/block/etc.
cheers,
george.