How to Choose an Alternator

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Choosing an Alternator...

Selecting the proper alternator is essential to the life of an electrical system on any vehicle. An undersized or incorrectly installed alternator can cause electrical failures, damage and even fire in some extreme cases. If you have questions about what kind of alternator your vehicle needs, feel free to contact Powermaster at 630-957-4019 or tech@powermasterperformance.com. You can also contact Concept One for questions about your alternator and pulley kits.

Make a list of your electrical components
Determine amp draw on each and total
Select an alternator with more amps than estimated to ensure long life of the alternator
See our website for additional tips
Call our Tech Support Line for selection assistance...

Important Stuff
It is important to know that the alternator cannot output full capacity at idle. Also, electrical demands are generally higher at idle mostly due to engine cooling fans running. When choosing an alternator, make sure that the alternator can output enough amperage at idle to cover the electrical demands.

Our alternators are shown with both top end amperage and idle amperage.

Available alternators:

CS130D		AD244
120/95 amp (standard)		180/135 amp (optional)
165/100 amp (optional)		220/150 amp (optional)

Amp draw of common auto accessories:

Accessory	Example Amps	Your Amps
Headlights / Tail Lights	10
Halogen Bulbs	10 ea
Dash Lights	2 - 4
Power Windows	15 - 20
Dash Lights	2 - 4
Air Conditioning	19 - 22
Electric Fans	30 - 50
Radio	4 - 10
Audio Amplifiers	15 - 250+
HEI Ignition	10 - 12
Electric Water Pump	18 - 25
Electric Fuel Pump	8 - 10
Air Suspension Compressors	20 - 50
Other
TOTAL AMP DRAW

Useful formulas:

Amps = Watts / Volts

Amps = Volts / 0hms

Charge Wires

One of the most missed install problems is the proper charge wire.
The connection between the alternator and the battery is very important.
An undersized charge wire, especially with high output units or improperly attached terminals, could result in voltage/amperage loss and alternator and wire damage.
Powermaster (630-957-4019 or tech@powermasterperformance.com) offers charge wires, ready to use, in various lengths with terminals on both ends and a battery terminal boot installed.

Charge Wire Size Chart

AMPS	Up to 4'	4' - 7'	7' - 10'	10' - 13'	13' - 16'	16' - 19'	19' - 22'	22' - 28'
35 - 50	12	12	10	10	10	8	8	8
50 - 65	10	8	8	6	6	6	6	4
65 - 85	10	8	8	6	6	4	4	4
85 - 105	8	8	6	4	4	4	4	2
105 - 125	6	6	4	4	2	2	2	0
125 - 150	6	6	4	2	2	2	2	0
150 - 175	4	4	4	2	2	0	0	0
175 - 200	4	4	2	2	0	0	0	00