I just got a 200amp alternator. Is it really necessary to upgrade to a
2-gauge wire to the battery?

 

YES the wire has to have capacity

 

you should also upgrade all the other wires such as battery ground, engine block to chassis, and possibly you starter cables too.

 

Starter cable isn't necessary....think about it, the alternator isn't putting out while starting!!

 

yea i guess your right, someone told me it should be upgraded but i never really thought about it

 

where is the block-to-chassis cable located?

 

i have a 200 amp alternator and have not upgraded any wires and have no problems, all lights with audio system operate fine with no problems, and none of my wires seem to be getting hot from carrying to much current,

 

the engine to chassis is at the back of the engine and a PITA to do... its a 1/2 inch socket i think on the engine btw, took me forever to find out what size it was

 

You are probably not getting the full power that you could be getting from your alternator. I upgraded my stock wiring with my stock alt (95amp) to 4awg and noticed and increase in power. You should be running at least 2awg with a 200amp alt. You can get the wiring at any car audio store by the foot. 14ft covered it in my 3.0L with a couple extra feet to spare.

You could just add a new engine to chassis instead of trying to replace that one. You can run a wire from one of the alternator mounting bolts. The current will take the path of least resistance (biggest gauge wire).

 

Sorry to thread jack, but don't you need to add a fuse or breaker when upgrading the wiring from the alternator.

 

Yes that is highly recommended. The stock 95amp alt runs through the fuse box into a 125amp fuse I believe. I just used my own inline fuse when I redid my wiring because it used less wire. Some alternators are internally regulated but it is still a good idea to put a fuse within at least a foot of the battery.

 

Yes, you need a fuse or breaker.