Hey Guys, Im sorry to see this warm weather go and cold winter months coming in. I Have and electrical question for you guys. I am running a 140 amp powermaster alternator with an Optima Red Top Battery. My main question is when I run My electric fan (95 Windstar Fan, small one only relayed with temp sensor), Headlights (also running with relays, as specified by MAD Enterprises), and my heater fan. My voltage drops down to 12 volts (iterior gauge reading) even when cruising at 3000 rpm. Should this be happening, it was my thought that the alternator would be able to handle these devices and would be getting atleast 13 volts especially at this rpm. My system is also wired like MAD enterprises recommends with the new buss bar and upgraded alternator and ground wire. I would just like to know if this is normal or if I should be looking for a bug in my system. And I have one other small question i didnt want to clog up the forum with. When I ran my new complete head light wiring harness i ran it between the fender and innerfender up to the firewall, to hide the wire and make it look neater. But I have not seen anyone else do that, is it dangerous to keep the wire in there, I mean i cant see it encase something i rubbing on it but i checked and I dont see anything in there that could cause problems. Well thank you guys for any Help you can provide.

Doesn't sound normal, not with a 140 amp alt. You said you're looking at an interior gauge. What is the voltage right out of the alt, + terminal on back of alt, under the same conditions, fan and headlights on? Where is the sense wire from the alt hooked up?

Where is the sense wire from the alt hooked up?
Thats what i was wondering as well

i used the kit, http://www.wiringharness.com/images/parts/27555.jpg, to hook up the alternator. the stock wire that was on the harness is used as the sensor wire. should I change this, to the way listed in the tech reference (http://www.chevelles.com/techref/ftecref14.html)? Im not able to check the voltage directly out of the alternato right now, sorry.

No don't change it to the way it is in the techref. I can't tell for certain what the wiring harness you purchased does but it looks like it bypasses the exteran voltage regulator and provides remote voltage sensing to the alt, which is what you want. Where is your interior gauge hooked up, where are your fan and headlights getting power from?

the fans and headlight relays are receiving power from a buss bar, which is getting power directly from the alternator. my system is wired like MAD describes (http://www.madelectrical.com/electricaltech/chevymain2.shtml) in the new sytem photo. as far the gauge i am not sure. somewhere under the dash lol i doubt that will help