I dont get it.

Heres my charging system.
My battery is 1 year old (die hard, biggest they had)
My alternator is 1 year and about 10,000 miles old. I put the stock alternator pulley back on, but i still run the 33% underdrive crank pulley.

When I start up the car voltage goes to 15 volts or so like normal. I can crank the subs and even at Idle it stays at 15 volts.
When my 18 degree fan switch kicks on and the fan comes on the volt gauge drops to 11 volts Immedately If im at idle, and then stays there, If i have ym stereo on it drops even lower!. The fans should not be drawing that much juice, anyone else ever run into this? Aside from cleaning the connections on the fan, I dont know what to do about it.

 

Sounds like one of your fans has a shorted out winding in the motor When this happens the fan works slow .. overheats and draws a whole lotta juice... unplug one of the fans at a time till y ou find if both draw the same amount of juice.... if they do then its a loose conection somewhere.. but if they dont... youll find the bad one pretty quick..

Marvin

 

good idea, thx.