its a s4 n/a. ive been combing through the archives all night and couldnt find my cars exact syptoms, the volt meter in the car reads a little over twelve with the battery hooked up, the car will run fine off just the alternator, i have bought a new battery, a new alternator, coils, plugs, and wires, sill no go, when the battery is hooked up to the car while it is running the car will cutout under anything more than 1/8th throttle, unhook the battery and the volt metere goes up to 14, and the car no longer cuts out. i have also checked all the wires in the car, none bare, swollen or corroded.

 

your volts should be at 14 when your car is running. But what i dont get is, are you saying you take your battery out and your car keeps running? it should die there is no way to keep your inectors flowing and no power to fire your spark plugs

 

yea with the car running i can unhook the posituve battery cable and the car keeps running, and actually runs better with the battery unhooked

 

Have you tried another battery in the car. Battery could be bad, as in internally shorted. Also check the battery ground wire connections on engine/chassis.

 

did you put the battery in backwards? once you start a car and the remove the battery, and the car is still running, then its not the alternator. its your battery, probably put in backwards.

 

umm no the i didnt put the battery in backwards, ive had three batteries in the car in the last two days, 2 were brand new, i bought the one put it in and it did the same thing so i took it back and got another one.

 

i found the problem it was the white/black wire on the back of the alternator. in the proccess of fixing it now. thanx for the suggestions

 

The purpose of the WHITE/black wire is to supply EXCITATION power to the rotor of the alternator so the alternator will function. That's on a series four car. Without that wire the alternator will still get excitation if the engine is rev'd up quickly to over say 2 grand and will keep on functioning until the engine is turned off. Then the next time you'd have to do the rev job once again to get it to put out.

The White/Black wire if probed with a meter should read 1-3vdc (wire still connected to the alternator), when the key is ON and engine OFF. That 1-3vdc is the excitation power I mentioned above and comes from the CPU near your right foot.

If the white/black wire is pulled off the alternator and key is ON, then the voltage on that wire will be close to battery voltage. Connect it back up to the alternator and the voltage should drop to 1-3vdc as stated in the ENGINE ELECTRICAL section of the FSM that is online free.

 

i did that and the white/black wire was 0 with the key on and it unplugged from the alternator, when it was plugged back in it was 3 volts, but that didnt fix my problem completely, my car is still cutting out under a load, just now it doenst die with the lights or any other accessory on, btw its running extremely rich

 

All of your wires from your battery ok? No splits in the casings of the wires to allow for shorts anywhere?

 

no ive checked them all several times, its wierd i used a multimeter on everything and the alternator is putting out 14.5 volts, the battery is getting 14.5 but the voltmeter in the car is showing 12.5. also i cleaned the cpu connectors last night but that only helped a lil

 

does anyone know what the 30amp head fuse controls in the engine bay, i have my short traced back to there but i dont know where the red wire runs too.