Hello all.

I debated which board on which to start this thread. I decided to start it in Electronics since it is fundamentally an electrical question. You'll see why I say this in a moment.

I have an 83 FB with a 2.8L 5spd with A/C. It has a new Die Hard Gold (less than 6 mo) rated for a T/A. The alternator was tested as putting out 67 amps at idle. The engine idles fine. The battery charges fine. The idiot lights are not warning me about anything. Engine power is fine.

The turn signals are slow when used within, say, 15 mins of starting the car. They are fine after that even with accessories and aux lighting on.

The headlights do flicker slightly at idle, but are bright and steady with a slight touch of the gas.

I asked my mechanic about upgrading the alternator. He insisted that the current alt is fine. Let the sleeping dog lie.

However, this is what the future holds for this car.
1. Upgraded sound system (assume modest amp and sub).
2. Full custom digital dash and instrumentation including LCD monitor(s).
3. Possible cameras and VCR to feed the monitors.

I know that 67 amps at idle is not going to cut it just by seeing myself write this.

I have searched through the Thirdgen boards for alternator info. I have learned enough to know that I need to ask the question that is the thread subject.

Most of the info on alternators that I have read in the boards seems to pertain to 8 cyl. How much alternator is too much alternator for an 83 V6 2.8L? I know that voltage is regulated, but can an alt be too strong for an application?

Also, what about wire gauge to the starter and battery? Should I go to a heavier gauge? If so, how heavy is heavy enough?

If anybody has updgraded the alt on an 82-84 2.8L, I would appreciate any advise that you have to offer!

Thanks,
Joe

 

From an electrical standpoint, you can't really have "too much" alternator. The alt. regulates itself by changing the duty cycle of the field coil and if you have a monster of an alt. and no current draw it'll just stay off most of the time. However, higher output alt.s are also larger, heavier, and require more HP to operate than smaller units. The best thing to do is figure out exactly what equipment you want to have in the car, find the amperage draw ratings and add them up. Add 15 to that number and then add the stock alt. output and that's how much current your new alt. needs to produce.

At a guess, a regular CS130 should be good at 105 amps.....if you find that you need more power there are 140amp upgrade ktis availabe.

 

if your lights are dimming then I would replace it. How many volts does it read at the battery when idling? should be about 15.

 

The Auto Zone upgrade alt is 105 Amp's for $60, it the best deal really. anything bigger and two 105's at $120 would be cheaper and better. You can then run one switchable on or off. But you would need to have one killer system.

I do know you never turn an alt on under load, If one is off and the engine is going, you gotta shut it off before you turn it on.

Myself I have found the 105 Amp's to be enough for a decent system and extra lights. Lifetime warranty, only blew one but it was cause of my strut brace. When I took off it would jump up and hit it but I knew sooner or later one would give. But before it gave up it ground a nice grove so the new one didn't rub.

 

Okay, to correct a mistake made on here, the ideal voltage at the battery when the engine is running is within half a volt of 14, not 15. When the alt produces 15 volts, kiss half the electrics in the car goodbye... the internal voltage regulator is shot in the alt and the computer is going to be the first victim of the overpowering (more sensitive to voltage spikes) .

And to speak on pricing: I just went out today and got myself a new 105 amp alternator (fancy that-can't change the blasted diode when it fails after all...) from Advance Auto for $65 ($60 when the guy took the $5 diode off the bill I had bought two hours before that and couldn't use! )