[issach428]

i moved my battery to the trunk. The grounds are 1/0 to the body frame,to the sub frame and then to the motor(72 firebird). Here is how the whole system is set up: from the batter+ 1/0 running all of the way to the starter selenoid. The alternator has the stud on the back with the 2 wire plug on the side. The large field wire (12gauge) runs all the way back to the disconect switch then to the + of the battery. the small wire runs to the idiot light. The +on the back of the alternator has 3 wires, 1 goes to the starter selenoid, 1to the ignition, and 1 to the ac/heater system. the original 2 gauge wire that ran to the battery up front is still connected to the starter selenoid. i have all of the wires that used to connect to the + of the batter running off it. I was told that i need to move the ac/heater wire and ignition wire from the back of the alternator to the starter selenoid. Would this fix my high rpm (when the car is hot) voltage drop problem?? my ignition system and fuel pump are messing up when the car gets hot at high rpm, i run out of fuel and the ignition system acts like i hit the rev limiter.

[issach428]

i moved my battery to the trunk. The grounds are 1/0 to the body frame,to the sub frame and then to the motor(72 firebird). Here is how the whole system is set up: from the batter+ 1/0 running all of the way to the starter selenoid. The alternator has the stud on the back with the 2 wire plug on the side. The large field wire (12gauge) runs all the way back to the disconect switch then to the + of the battery. the small wire runs to the idiot light. The +on the back of the alternator has 3 wires, 1 goes to the starter selenoid, 1to the ignition, and 1 to the ac/heater system. the original 2 gauge wire that ran to the battery up front is still connected to the starter selenoid. i have all of the wires that used to connect to the + of the batter running off it. I was told that i need to move the ac/heater wire and ignition wire from the back of the alternator to the starter selenoid. Would this fix my high rpm (when the car is hot) voltage drop problem?? my ignition system and fuel pump are messing up when the car gets hot at high rpm, i run out of fuel and the ignition system acts like i hit the rev limiter.

[george kujanski]

What makes you think you are getting a high RPM voltage drop?

From your description, the voltage to your ignition and AC/heat will be greater than at the battery since the battery is in the rear when the alternator is charging. If you are truly losing voltage at high RPM, perhaps the large wire from alternator terminal #2 (battery sense) to the disconnect switch is loose and due to vibration, etc. the alternator is shutting down at speed. Since the battery is at the rear, then you would be getting lower voltage to the ignition due to cabling length, etc.

George

[issach428]

Do you see any problems with the way i have it wired now?

[george kujanski]

From the text description, it sounds ok, but I still wonder why you say you are getting a voltage drop at high RPM, and your ignition, fuel pump is shutting down.

George

[issach428]

i am not 100% sure i am having a voltage drop, i have checked all of the mechanical sides of the problem, maybe i am overlooking something. I read that the msd box will act this way if it doesnt get enough voltage, and the fuel pump wouldnt flow enough fuel if i had a voltage drop. i will re check everything. i had the alternator field wire accidentaly hooked up to the ground on my battery for about 2 days. would this damage anything in the alternator that would cause it to act funny?

[george kujanski]

Which wire are you calling the "field"? A 10SI or 12SI does not have an external field connection.

Secondly, will connecting any of the two wires to battery neg damage the alternator? The term #1 wire, probably not. The term #2 wire, I don't know; that would take an experiment.

why not connect a voltmeter to the power connection and ground connection at the MSD and fuel pump and see what happens at high RPM? Beats speculating....

George

[issach428]

well turns out it wasnt electrical..sorta the rev limiter chip was bad. i took it out and the misfire went away. as for the fuel pump, the filter by inspection was clean but i could barely blow through it. cars are so much fun!!!!!