Big 3, most important?

[maylar 10+ year member]

The smallest of the big 3 in most cars is the neg battery to body wire. It's also the shortest and usually easiest to replace. Alt to battery + would be second. The cable from bat to engine block has to carry starter current so it's usually pretty beefy. That one would be last on the priority list.

 

[quackhead 10+ year member]

The smallest of the big 3 in most cars is the neg battery to body wire. It's also the shortest and usually easiest to replace. Alt to battery + would be second. The cable from bat to engine block has to carry starter current so it's usually pretty beefy. That one would be last on the priority list.

I always figured the engine block to chassis ground had to be the same as the Alt to batt., since the Alt case to alt bracket serves as the alt ground...or am I totally wrong here?

 

[maylar 10+ year member]

I always figured the engine block to chassis ground had to be the same as the Alt to batt., since the Alt case to alt bracket serves as the alt ground...or am I totally wrong here?

Technically that's 2 of the 3 wires combined. Factory wiring goes from battery negative terminal to the engine block (1 wire) and from battery negative to the body (another wire). You are correct that the first wire also carries return current from the alternator, but starter current is the determining factor in the stock wire gage. Getting the alt/bat current to the chassis is the function of a separate wire and it's often pretty small - I think my 85 Olds had a 10 gage there. So in terms of priority, I'd do the skinny ones first.

 

[rebelfromva 10+ year member]

big 3 is not need for that setup...

 

[sbelew 10+ year member]

So for learnings sake, at what point would you guys recommend upgrading in terms of wattage for;

Big Three Upgrade?

Battery Upgrade?

Alternator Upgrade?

 

[rebelfromva 10+ year member]

Big 3-1000

Add second batt-1500

Alt -3k plus

 

[DukeNut 10+ year member]

The smallest of the big 3 in most cars is the neg battery to body wire. It's also the shortest and usually easiest to replace. Alt to battery + would be second. The cable from bat to engine block has to carry starter current so it's usually pretty beefy. That one would be last on the priority list.

totally agree with maylar here. if you think about it, you use the pos from battery to amp and then ground the amp to body, so this is where the circuit (body to battery) is completed. i actually experienced this with helping the dimming issues on my son's car before doing the other 2 a few days later.