Installing Alternator incorrectly?
filed in 1966 Mustang
Question: Ok here is my situation… Amateur mechanic. I removed the alternator from my girlfriend’s car 2 months ago, I have been sick with hepatitis since and am just now getting around to installing the new one (the old one was toast). The battery was completely drained. I am not sure if I connected the two wires other than the ground to the alternator correctly. I am sure the ground is connected correctly. The post on the alternator marked Battery and the other one (not the Stat) are the ones I am concerned with. I followed the line from the battery and it looks to run to the battery but I am not positive (runs across to the other side of the firewall and then back for some reason). I jumpstarted her car and drove around for 10 minutes tonight. After stopping, there was absolutely no juice, battery seemed completely drained again. Now, the battery was drained to begin with so I am now completely charging her battery (with a charger with auto-stop no doubt).
What I want to know is this: a) Would the vehicle even start if I connected the two wires incorrectly? b) Would the ammeter read a severe discharge if it were connected incorrectly? or would there be some other method of determining this? c) Is there a possibility of damaging the vehicle if connected incorrectly and if so, what would be at danger?
Thanks for humoring me, this is quite embarrassing but as I said, I am a beginning mechanic. The vehicle is a 1966 Mustang.
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Thank you so much!
A battery can be drained to the point it will never take a charge again. Buy a multi-meter (you will use it again and again) and check voltages.
1. With the new battery installed, check the voltage at the battery. It should read ~12V.
2. Start the car. The voltage now should read ~14V. The higher voltage is what “pushs” the charge back into the battery. If it stays at 12V – it could be a bad alt, wiring, or regulator. I would recommend you stop by an auto-parts store and check out a wiring diagram for this car. That should answer your questions.
The post is the main alternator output, and is usually wired to the same starter solenoid terminal as the battery positive cable, through fusing. The other wires go to the regulator, or if the regulator is built in – one is the voltage sense and the other is to supply a current to start energizing the rotor field coil in the alternator. You must not confuse them, so the wiring diagram is essential. The alternator will not work if the hookup is wrong.
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