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Alternator charging issue

6K views 15 replies 6 participants last post by  1ijack 
#1 ·
I have put a 05 alternator on a 99 gt and it worked get but now I have started going through 4 alternators and 3 batteries. The alternator is charging at 11.75 volts on the car, but on a bench tester it tested at 13.54 volts.

Need help with this Ford has no solution and asking for help or I am sunk. If you can help please respond need suggestions on this soon.
 
#7 ·
U won't have to sell. Sometimes these probelms seem daunting but ends up being something simple. So many times I got the car someone else gave up on ans sold cheap then I fixed it in minutes. Sometimes just takes a fresh set of eyes I guess. Take a step back and sleep on it if u have to. Ull get it
 
#9 ·
What amp alt are u using? They make two different alts with two different amp ratings. I had similar problems until got the alt with the higher amp rating. Still seems like a short though.

---------- Post added at 11:36 PM ---------- Previous post was at 11:33 PM ----------

The voltage on ur battery should be 12 to 13s with the car off and 14s with the car running.
 
#12 ·
Go to your Hanes manual. While engine is off, connect test light between the negative terminal and ground. It it lights, you have a fault. You shouldn't have positive voltage on the negative side. Next, while keeping the test light connected, begin pulling fuses (under hood first) till the light goes out. If the light goes out to, say the alternator, but fuse is undamaged, get a multimeter with a buzzer if possible and begin checking the grounds. If you have a buzz with a hot and ground. Guess you know what that means. Also, get your alternator tested. Autozone, advance auto, pep boys, they all do it for free. One more thing. Try starting the engine without the radiator fan, it might be burned. It melts down (fire hazard) when it quits.

---------- Post added at 08:30 AM ---------- Previous post was at 08:29 AM ----------

LAS97GT said:
Go to your Hanes manual. While engine is off, connect test light between the negative terminal and ground. It it lights, you have a fault. You shouldn't have positive voltage on the negative side. Next, while keeping the test light connected, begin pulling fuses (under hood first) till the light goes out. If the light goes out to, say the alternator, but fuse is undamaged, get a multimeter with a buzzer if possible and begin checking the grounds. If you have a buzz with a hot and ground. Guess you know what that means. Also, get your alternator tested. Autozone, advance auto, pep boys, they all do it for free. One more thing. Try starting the engine without the radiator fan, it might be burned. It melts down (fire hazard) when it quits.
Correction: get your starter tested.
 
#13 ·
I have a simple question......does an 05 alty work on the 96? And how did u do it? Oh and maybe some silly input does the voltage at the battery match the voltage from the alty wire to ground? I read feom all data on 05-09 ha ing issues with altys due to pcm comm wire broke or stripped. Would look into your wiring diagram to see where a stripped wire would ground out or see where a loss of connection would be
 
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