Electric Fan Voltage Drop

If dip to 11 volts then your alternator is either not delivering the 100 amps or the fan belt is slipping.

Electric fan voltage drop.

There must be little or no voltage drop at the fan motors. The voltage drop test is a dynamic test intended for use mainly with high current draw systems such as the starting system charging system or items such as a heater fan electric fuel pump or. I switched to a 170 amp holley alternator along with a new drive setup on my ls and added a 4 awg feed wire. Grab a volt meter and measure the voltage at the alternator.

The alternator is tricked into working harder to compensate for the 1 2v difference it is seeing. Might help you a lot with the voltages your are seeing. I have never had any problem with the battery going dead or any long term charging issues. When electric fan installs don t perform as expected the problems are often traceable to under wiring and or poor splices and grounds.

Voltage would start off at 14 0 and drop down to 12 5 with both fans on entropy fans are big power hogs and everything else on. You may double the fan belt or use a serpentine belt so it won t slip. It is recommended that the voltage drop should be less than 5 under the fully loaded condition. Put a diode in series at the alternator on the excite trigger wire.

If does not drop then run a heavyer gauge wire between the alternator and junction terminal. When the air is on and the auxiliary electric fan kicks in my voltage drops from 14 2 down to about 12 5 13.