[JUDGE3]

Installed the powermaster 150amp on my 72 firebird.

ran the 6 gauge wire from the alternator battery lug to the battery lug on the starter per instructions.

where do I hook up the previous wire that connected to the alternator battery lug to get key ignition power? its the alternator wire with the fuse link. see pic.

[TedRamAirII]

To the big lug on the Alternator

[JUDGE3]

? instructions state to install the bigger 6 gauge wire from alt lug to starter lug I did that.

The stock fitting there doesn't even fit the powermaster lug. if I attach that wire along with the new 6 gauge wire to the alt lug, doesn't that defeat the purpose? cause problem?

[johnta1]

Ted is correct.

The battery lug to alternator lug is the power to/from battery.
The wires you show connect to alternator lug to provide power to the car.
Otherwise no power to anything except starter.

[JUDGE3]

having the 6 gauge wire due to the 150 amp alt along with the other smaller gauge wires won't effect anything? forgive me, i'm terrible at wiring. so the 6 gauge required is due to otherwise, without it, the 150 amp alt would burn up the smaller wires?

[johnta1]

If you actually need that 150 amps, you should have a power buss probably?

But yes the bigger wire will handle the extra amps which would go toward the battery. (to charge it)

The power wire to the car will use whatever it needs which should be a lot less than 150 amps.

The circuit you plan on having that uses 150 amps should be on a separate circuit and splice into the battery lug/cable.