I could use some help to certify an assessment of an ongoing automotive issue. The vehicle is equipped with a high-performance electrical fan (40 amp draw/10 AWG), and I suspect that existing wiring is intercepting the charge from the battery.
Here is the current wiring diagram:
- There is an AGM automotive battery under the rear seat, and it's grounded to the chassis.
- There is an electrical junction box located under the hood where the battery and alternator connect.
- The positive battery wire runs there and connects with alternator output (+). Basically, this is where the alternator flow meets and charges the battery.
- The aftermarket electrical fan is also connected to the electrical junction and pulls the power from it on demand when the vehicle reaches operating temperature.
All three positive leads for (battery, alternator, and electrical fan) are connected at that junction. The positive wire running the electrical fan is also shorter than the battery wire that runs all the way to the back in the car.
Is it scientifically correct that the fan, at full operation (40 A), will intercept the alternator charge from the battery? If so, how significant would the interception be, and would it actually impact the charging of battery during normal operation? Please note that the alternator on the vehicle is rated at 140 A.
If there is an interception, would re-routing the positive wire from an electrical fan directly to the positive battery terminal remedy this issue?