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Discussion Starter · #1 · (Edited)
Hi,

I've searched net how to upgrade my sound system with amplifier and found that big three is essential and cheap to do by running 2 or 4 gauge wires from battery to alternator instead of basic ones(or if not possible to replace then just running extra wiring):

1. Alt pos to battery pos -- the only positive run for the big 3 and is necessary to supply current to the rest of your system.
2. Vehicle chassis to battery neg -- your vehicle's chassis/frame needs to be grounded as that's what multiple electrical components both factory and aftermarket use.
3. Alt casing/Engine block to battery neg -- in order for your alternator to charge it needs a grounding point. The casing on the alt is used as a ground. Most people will attach a wire to the engine block because the alt is bolted onto the engine block. For minimum resistance, find a bolt that is NOT the alternator positive terminal, and attach it there.

New power wire can be fused for extra safety.

Have any1 done this ? what thickness wires mentioned above does your car have?
I'm thinking to do this when installing amplifier.
 

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AO Silver Member, 155 Lounge Winner 09
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I routinely do 2 of the 3: battery neg to chassis; engine block to chassis.

I find it impractical to change the wire from the alternator to the battery positive terminal in these cars. Hard to access the wiring.

In my GT, I have 0ga from engine to chassis (original chassis groundwire bolt), and 2x 0ga from new battery terminal to the same bolt. Same in my 155. And will do the same in the 75 (though I will complete the Big3 in this car because it is easy). All these cars incidentally run aftermarket stereos and Optima deep cycle batteries.

As long as the wiring is thicker than the factory wiring, it's an upgrade. You'll probably find the factory engine-chassis wire is 2ga, and the battery neg to chassis is 4ga or 2ga.

:)
 

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Discussion Starter · #3 ·
ill use 4gau wiring kit for amp only so quite alot consumption probably i do need then to get 0gau wiring for alternator. and you say its hard to replace? what about 156 ? better to run another extra wire instead changing ? did you fuse your wires?
 

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AO Silver Member, 155 Lounge Winner 09
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I used to have a 2.0TS 156 with a big ICE system. In that car, I did not change the alternator-battery wire; I only fitted an Optima deep cycle battery, 2x4ga battery-chassis groundwires, and 0ga engine-chassis groundwire. I had no power issues.

You can have a look, and attempt to change the alt-batt wire. I didn't think it was worth it.

The only fuses were along the POSitive wires from the battery to the stereo.

:)
 
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