Accessory Amp Draw
Headlights/tailights 4-6
Halogen bulbs up to 10 amps per bulb
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 8-20
Air Suspension Compressors 20-50*
*Intermittent Draw

Calculating Alternator RPM
When considering idle output of an alternator, pulley ratio must be taken into account. All measurements of output of an alternator can only be taken at the shaft of the alternator. Thus, idle amperage is calculated at 2,400 alternator rpm. On a street vehicle, the average pulley ratio is 3:1, meaning that 2,400 alternator rpm is equal to 800 engine rpm.

The connection between the alternator and the battery is very important. An undersized charge wire or improperly attached terminals could result in voltage loss. When upgrading an alternator there is an increased volume of current, and in most cases that means the size of the charge wire should be increased in size as well.

Recommended Charging Cable Gauge Size
AMPS Up to 4ft. 4 - 7ft. 7- 10ft. 10- 13ft. 13- 16ft. 16 - 19ft. 19- 22ft. 22- 28ft.
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 0
SOURCE
Powermaster
1833 Downs Drive
West Chicago
IL  60185
630-957-4019
www.powermasterperformance.com