Major Electrical Issue...

[USArmyCombatMedic]

Hey guys so I have a bit of an issue here. I started a thread a few days ago called Starts Fine and Stalls but after listening them and working on my truck I have realized that it has another major issue. I think I have the wiring messed up somehow.

So heres what happens, if I leave the truck off overnight the battery will hold its charge at about 12.7 or 12.8 volts but the problem is when I turn it on. I have to have a battery charger hooked up to it in order to turn it on. It starts and runs at about 12.7 volts, as soon as I remove the battery charger the truck will die in a matter of 5-10 seconds because the volatge drops that fast to 11.85 volts. What is causing the voltage to drop this fast? As far as I know all of the grounds and wires are hooked up like they are suppose to be. The alternator works as it shoots out anywhere from 14.5 to 16 volts and was also tested by O Reillys. Im sure this is something stupid and easy that I am just overlooking. Thanks for the help in advance guys!

[clapage6]

Originally Posted by USArmyCombatMedic

Hey guys so I have a bit of an issue here. I started a thread a few days ago called Starts Fine and Stalls but after listening them and working on my truck I have realized that it has another major issue. I think I have the wiring messed up somehow.

So heres what happens, if I leave the truck off overnight the battery will hold its charge at about 12.7 or 12.8 volts but the problem is when I turn it on. I have to have a battery charger hooked up to it in order to turn it on. It starts and runs at about 12.7 volts, as soon as I remove the battery charger the truck will die in a matter of 5-10 seconds because the volatge drops that fast to 11.85 volts. What is causing the voltage to drop this fast? As far as I know all of the grounds and wires are hooked up like they are suppose to be. The alternator works as it shoots out anywhere from 14.5 to 16 volts and was also tested by O Reillys. Im sure this is something stupid and easy that I am just overlooking. Thanks for the help in advance guys!

Well if the alternator is indeed giving 14 Volta while its on the truck.... The voltage is not making it to the battery. Is it a 3 wire alternator? I would first check to be sure your alternator is indeed giving proper voltage while its installed on your truck. Then if it is, you can trace the problem between it and the battery

[USArmyCombatMedic]

Thanks for the help! Think I found the problem. The battery cables are hooked up wrong I believe. Negative battery cable grounds on the alternator bracket and the frame. Positive battery connects to top post on the starter solenoid and the post on the alternator correct? For whatever reason the positive cable had both connections to the starter solenoid one on the top post and the other on the passenger side post. I have no positive wire to my alternator.