Need Help with Big 3

[Oak244 10+ year member]

I just installed my new HO Alternator, and have 0 awg wire going from my Alt to my battery. I assume do to physics classes, that I must now have 0 awg ground wire installed as well. Here is what my car looks like. What I am wondering is, Is it ok to add a new 0 awg wire and ground it at the exact same point with the original?

There is also this wire, connected to the stock ground wire, which I have pointed out here with blue arrows. What is the purpose of this wire?

Lastly here is a closer picture of where that wire that connects to the stock ground point.

I do not want to cause any fires, so before I do anything I would like some experienced folks to tell me how you would add a 0 awg ground in this car. Thanks

Oh and where might I look for the chassis ground wire? This car is a 1991 Geo Prism, same car as the same year Toyota Corrola.

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[blackgeltabs 5,000+ posts]

Yes that will work fine. I would sand some of the paint away to make a better connection. Read the big 3 thread again. batt to chassis, bat to alt, alt to chassis.

I usually just find a decent size bolt to undo and put the ground under that, easier than drilling if theres a bolt available in the area.

 

[Oak244 10+ year member]

Yes that will work fine. I would sand some of the paint away to make a better connection. Read the big 3 thread again. batt to chassis, bat to alt, alt to chassis.
I usually just find a decent size bolt to undo and put the ground under that, easier than drilling if theres a bolt available in the area.

Are you saying run the 0 awg wire to the bolt in the first pic, or the last pic?

 

[Fred85 10+ year member]

third wire is common on cars

the electrical system is grounded to both the block and chassis

 

[Oak244 10+ year member]

Ok got ya. I still am not sure. should I run my 0 guage wire to the bolt in pic 1 or the bolt in pic 3?

 

[blackgeltabs 5,000+ posts]

Whichever is shorter distance, both will work just fine

 

[Oak244 10+ year member]

Whichever is shorter distance, both will work just fine

Oh ok, the shortest is to the point in the last picture.

 

[RegSo UnGh 10+ year member]

did u say you couldnt find where the chassey is grounded? if so, see where either of those stock grounding wires lead to...the other end just may be the engine block connection u were looking for..... then 0gauge the S H I T out of it

and remember its Alt to Battery Positive, Battery Negative to Chassey, Battery Negative to Engine block (when u find it) just adding wire to those of course

 

[Oak244 10+ year member]

did u say you couldnt find where the chassey is grounded? if so, see where either of those stock grounding wires lead to...the other end just may be the engine block connection u were looking for..... then 0gauge the S H I T out of it
and remember its Alt to Battery Positive, Battery Negative to Chassey, Battery Negative to Engine block (when u find it) just adding wire to those of course

Well the first picrure is the Battery to Block. Pic 2 is the Chassis to Block. I left the stock wire the way they are, and added a 0 awg wire from the Nagative, to the chassis connection in pics 2 and 3.