solpushcart

Ok, I've replaced the alternator that was pushing out 12 volts. Now I've got 14 volts coming out. The battery also needed replacing as the amps were real low. Now I have a new one. 700 CCA's. My question for all you automotive electrical guru's is why does my battery light continue to come on and off? I guess I'm trying to figure out if there is something else I should be looking at or is this one of those, "turn the key on and off 3 times, turn the headlights on and off, step on the gas, turn the radio on, step outside and turn around 4 times, then start the engine" and the light resets? The light comes on and off at different intervals now, unlike when it would go out upon acceleration and on stopped at an idle. Which gives you a good idea to check the alternator.

firehart2

If it is an aftermarket alternator then that is more than likely your problem. There's some weird issue with the voltage regulators that causes the battery light.

solpushcart

So, are you saying after over $200, that I need to replace it with a $450 motorcraft?

solpushcart

Or is it as simple as replacing the regulator? What would be the negative with driving it anyway? Is it a matter of killing the battery?

Ifallsguy

take it back and get an exchange. Or go to Autozone or O'reily and have them test it. They can do it off the truck. The alternator should be exhanged

solpushcart

Thank you both. The new one only has less than an hour of usage. I just hope O'reilly's will take it back and let me pay the difference for the Motorcraft one. The tester said it was putting out 14 volts, so I know the alternator is good. I just never thought Ford would make parts proprietary for things like this. Live and learn.

firehart2

Yes it is a matter of replacing the regulator with a motorcraft regulator. This is beginning to become a common problem with the aftermaket unti on these trucks. A good alternator shop can stack a new brush on top of the original worn brush, thus creating a new wearable contact surface. Since there is less than 3 amps of current flowing through this part if the alternaor, stacking brushes is completely acceptable and is deemed reliable. The main cause of failure of these units is an ecesessively worn rotor contact, which can in turn accelerate the wear on the contact brush with in the voltage regulator assemlby. I routinely choose to rebuild my alternators as opposed to replacing them with a cheap aftermarket unit. A quality aftermarket unit such as Powermaster, etc is the only acceptable replacement when needing to upgrade to due needing a higher capacity unit. This is a bit of a long winded answer, but just wanted you to understand the need to stay away from parts store alternators which are more than likely rebuilt outside of the country anyway.

solpushcart

Just a quick note, after 9 days waiting for O'Reillys to get the alternator in, the manager told me they no longer have it. So I got online and found the dealer here had one for $212. Took the other back, put the new one on, and no more light. Thanks again for your help. It is a learning experience.

dnlow

This is good info. I will keep it in mind if I ever need an alternator.

firehart2

Excellent! I'm glad to be able to help out.