alternator amps

[Ironmike]

Hi guys! decided to go to electric fan and worried about my alternator. Currently have a NAPA rebuilt that I bought for a 71 Dart with A/C. Don't have A/C, but run an in tank fuel pump. No fancy stereo, no power anything.
The fan I'm looking at draws 25 amps. So...... will my current alt be enough?

 

[Dana67Dart]

Search FABO for "overheating"

Read the issues and see if you can see the common denominator

 

[Mattax]

Also search for wiring strategies with EFI. Its more than just the alternator not being able to handle those extra loads at idle. The power supply scheme is not adaptable to what you are doing. You'll need to change the scheme and the execution to handle those near constant additional loads

 

[Ironmike]

no overheating problems at all. just like to get back that 35HP or so that an engine driven fan sucks. Dyno doesn't lie.

 

[66Valiant528]

I would suspect you need an alternator upgrade. You need to find out what your systems are drawing at idle and then get an alternator that puts out at least that at idle. 65 amp rebuilt napa unit is probably putting out less than you are asking for at idle. Ultimately you will run down the battery. Don't forget to upgrade your wires. Efi, electric fuelpump and a fan?

 

[MadScientistMat]

There are a couple different alternators; OE could be anything from 23 amp (nope!) to 60 amp (should be OK).