I like this simple way of adding a good known ground.
The battery is grounded to the body. Why not make a true large ground in front from body to engine ?
Maybe some issues that alway say "Oh the battery is no good" when all you have to do is add this ground.
What gauge battery cable did you use ?
OK started looking. Need a ground strap called lug to lug. A quick search and found an 18 inch.



Here's away to crimp on a lug terminal end.

 

If the battery has a dead cell or low voltage or cranking amps, how is just add this ground going to help?

 

Who to say he has a bad battery?
Did you ever have a race car with battery in the trunk ? I have.
There are two ways to make a complete good ground to the engine. Ground battery to body, body to engine/chassis.
Run a larger size cable all the way to the engine/chassis from the battery. Or cable with more strands in it of the same size.
The person is making a better known ground connection to begin with and not relying on the factory.
If you have a 4/0 cable at the battery you should have a 4/0 cable ground at the engine/chassis using battery to body, body to engine.
Now there is a possibility of a lower voltage drop to components because of a known good ground.

 

Ah, Cliff did in #4 and #8 , but no confirmation of a battery load test.
The ground idea fixed the issue of a bad wire or contact of an original ground connection.
And yes I fully understand ground wire improvements .

my question was directed to your statements.....

I like this simple way of adding a good known ground.
The battery is grounded to the body. Why not make a true large ground in front from body to engine ?
Maybe some issues that alway say "Oh the battery is no good" when all you have to do is add this ground.
What gauge battery cable did you use ?
OK started looking. Need a ground strap called lug to lug. A quick search and found an 18 inch.

 

Uh, the alternator is bolted onto the engine. If grounding the alternator helps it means that the engine to frame ground is bad, that is at the top of the transmission to the radiator support. It should not take 6-8 gauge wire to do the job.

 

For the ground cable from the alternator I used a negative battery cable I bought at walmart. It worked well because it already had terminal ends on it.
Thats the good news. Bad news is its not fixed😕
I test drove it after watching the Indy 500 (that was a great finish!). After driving about 15 miles the power steering message appeared(although the power steering was still working) and the gauges flat lined and it started shifting rough. It ran better than ever before that happened. Im really discouraged now.
Could a failing steering motor cause the other symptoms? Am I looking at a bad bcm? I hate to take the car to a dealership. Ive looked online and the steering motor is unavailable anywhere i looked. Thanks for everyones help

 

The power steering motor is covered by a special lifetime warranty, but that is not the problem. What was the reason for suspecting the tail light ground?
Check your battery and alternator.

 

And so, I ask again , could you have the battery load tested, these symptoms are indicative of a low voltage issue or dead cell in the battery.

 

Battery is brand bought yesterday and I charged it fully. I have it fixed now. Came across a post by malibuhhr from 2017. He was having a similar problem and had spent several hundred dollars replacing battery, alternator etc. He even had the dealer ignition switch recall done and none of that fixed it. What did fix it was replacing the run/start relay. The contacts were burned inside of it. In my case it was the relay on the bcm. I pulled it and put a little dielectric grease on the connectors and pushed it back in. Just drove it 40 miles and let it idle with the ac on and all is fine.

 

Great, new battery ( I wasn’t aware)
same relay new dielectric grease.
Awesome, it lives!! Enjoy the drive