High output alternator

[1973c10]

Hey all


I have a one wire 65 amp alternator now
and am looking to upgrade to a 150 Amps at Idle / 220 Amps at Full Output,
right now it is wired from the post on the alternator into the fuse block
if I upgrade and go from the post on the alternator directly to the battery
what size wire should I use

 

[C10MixMaster]

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Hey all


I have a one wire 65 amp alternator now
and am looking to upgrade to a 150 Amps at Idle / 220 Amps at Full Output,
right now it is wired from the post on the alternator into the fuse block
if I upgrade and go from the post on the alternator directly to the battery
what size wire should I use

looks like 4GA

 

[1973c10]

You must be registered for see images attach

looks like 4GA

Thank you

 

[1973c10]

is there any issue with running that high of amp alternator

 

[Matt69olds]

Why do you need that much capacity? There is no problem running that big alternator, just make sure the charge wire is big enough to handle the current

 

[1973c10]

Why do you need that much capacity? There is no problem running that big alternator, just make sure the charge wire is big enough to handle the current

2 electric fans , large sound system , AC , halogen headlight and so on
if I use a amperage calculator its about 152 amps
Driving at night things start going dim and the voltage drops it under 12v

I was going to run 4 GA with a fuse from the post on the alternator directly to the battery
about a 2 foot wire

 

[Frankenchevy]

I have a 175 amp Tuff Stuff alternator and settled on 2/0 wire after speaking with the manufacturer.

 

[gotyourgoat]

2 electric fans , large sound system , AC , halogen headlight and so on
if I use a amperage calculator its about 152 amps
Driving at night things start going dim and the voltage drops it under 12v

Curious to know if an alternator throwing more juice is going to help with the lighting without wiring upgrades.

Wiring upgrades to the lights that is.

 

[1973c10]

Curious to know if an alternator throwing more juice is going to help with the lighting without wiring upgrades.

Wiring upgrades to the lights that is.

We will see

I installed a new complete painless wiring harness about 3 years ago
I have no problems until night driving and after about an hour or so the voltage starts to drop
and stuff starts to dim

 

[ali_c20]

Are you running a heavy duty wiring harness with relays for the lights?

 

[MikeB]

What is the voltage at the battery and headlights when they start to get dim?

Have you used a DC current clamp on the fuse panel feed wire to measure the current draw with all accessories running?

 

[1973c10]

Are you running a heavy duty wiring harness with relays for the lights?

Yes I am

 

[1973c10]

What is the voltage at the battery and headlights when they start to get dim?

Have you used a DC current clamp on the fuse panel feed wire to measure the current draw with all accessories running

12.5 volts at the battery and headlights when they start to get dim

No I have not tried a DC current clamp on the fuse panel feed wire to measure the current draw with all accessories running

 

[1973c10]

This is why I think I am pulling to many amps
My current alternator is 65 amps
I have 2 Electric Cooling Fans 15 amps each ( 30 amps total )
halogen headlight 18 amps
Instrument Panel 2 amps
Lamps, License Plate 1 amps
Lamps, Side Marker 3 amps
Lamps, Tail 5 amps
CD/Tuner with Amp 40 amps
Ignition 10 amps
Electric Fuel Pump 6 amps
plus thing I don't run all the time like AC , Heater Defroster , Dome Light , Back-Up Lamps and so on

 

[MikeB]

You forgot brake lights.

Yeah, a 65 amp alternator is not enough for that load, and could certainly be your problem. But I think a 140 or even 120 amp model should be more than enough. And if you can mange routing the large 4 gauge charging wire, you will have zero voltage drop from alternator to battery.
I haven't done car stereos since the 80s, but I have to wonder how much volume it would take for yours to draw 40 amps. Would sure like to see pictures of the installation.