Alternator question

M

magic_marker

Registered
Hey gang,

Earlier today, I brought the Mark in to have a new inside rearview mirror put on. The doors were open the whole time.

When they finished and I started the car, it cranked really weakly, but it started, and then different idiot lights were flickering (ABS, traction control, etc.) No "check charging system" message appeared.

I tuned off all lighting and accessories, let it idle in a parking lot for awhile, and the flickering stopped. I then drove it on the highway for about 15 minutes directly to NAPA.

They used their little multimeter thing and determined that the alternator was putting out approx 13.5 - 13.3. The battery tested A-OK.

My question is: what should a properly-running alternator put out?

Also, is there a consensus on the best place to buy a truly NEW oem alternator?

By the way, the alternator appears original, and the Mark has almost 109k on it.

Thanks!

Scott

I
 
RE: Alternator question

Depending how long the doors were open, it sounds to me like it may be a marginal battery and the alternator is probably OK.

Obviously the battery was weaker when you went to start the car, but maybe the battery terminals should be checked or replaced. The flickering lights is usually a sign of low voltage. The message center will not indicate a low voltage Check Charging System warning until the voltage is less than 9 volts - not much good to warn you then.

Turning off all lighting and accessories and leaving it idle was good as it charged the low battery.

The voltage output of the alternator is highly dependant of the load and engine RPMs. From another post:

Testing your charging system quickly with a digital voltmeter (assuming charged battery):

1. Test battery voltage with engine off. Check at battery terminals at clean terminal or clamp, not the bolt or nut. Record voltage. This is your battery's standing voltage.

2. Start engine & run at 1500 RPM. With no other load (doors closed? Underhood light off? Auto headlights off?) - record voltage. Voltage should be higher but not by more than 2 volts. This is your charging voltage without load.

3. Turn on heater or AC to MAX along with turning on highbeam headlamps. Increase RPMs to 2000 RPM. Voltage should be a minimum of 0.5 volts above your standing battery voltage. This is your charging voltage with load.
Click to expand...

As far as the best alternator, my current opinion(not to be confused with my past opinion or any future opinion) is to recommend a '96 Cobra alternator. FiveStarFord $ will be hard to beat. You have the opportunity to wait on shipping and get what you want at a good price, so that is rare. Most of us have to settle for a AutoZone reman with a much needed lifetime warranty or pay top dollar for a OEM unit from a dealer or other source.

A word of advice if I may; disconnect the battery during any work that requires the doors to be opened any significant length of time, or hook up a small battery charger.
 
RE: Alternator question

Thanks for the words of wisdom, JP.

With my last few law school finals coming up this week, I didn't want to chance it with my old alternator.

I bought the NAPA reman with a lifetime warranty for $209(after core).

Easy install, and the symptoms I had earlier are no more. Guess I caught the alternator just as it was starting to fail. Rest in peace, oem Ford part...

Thanks again,

Scott
 
RE: Alternator question

........Or, you can just get a G2, and the interior lights will turn off automatically if the doors are left open for more than a few minutes! :) I go to Ace Armature in Pawtucket, RI for my alternators. They have the 130 amp NEW FORD G2 alt. for $130 after core return!! No aftermarket alternators here!

-Joe Michael
 
RE: Alternator question

........Or, you can just get a G2, and the interior lights will turn off automatically if the doors are left open for more than a few minutes! :) I go to Ace Armature in Pawtucket, RI for my alternators. They have the 130 amp NEW FORD G2 alt. for $130 after core return!! No aftermarket alternators here!

-Joe Michael
Click to expand...

Properly working Gen1's also have this feature. I can not remember if it is 45 minutes or 60 minutes though. But I do know mine shuts down after a little while.
 
RE: Alternator question

........Or, you can just get a G2, and the interior lights will turn off automatically if the doors are left open for more than a few minutes! :) I go to Ace Armature in Pawtucket, RI for my alternators. They have the 130 amp NEW FORD G2 alt. for $130 after core return!! No aftermarket alternators here!

-Joe Michael
Click to expand...

Properly working Gen1's also have this feature. I can not remember if it is 45 minutes or 60 minutes though. But I do know mine shuts down after a little while.
Click to expand...

The RKE(Remote Keyless Entry) module does control this. From the manual:

How The Circuit Works

Voltage is present at all times, through Fuse 6 to the Main Light Switch. The I/P Cigar Lighter Lamp is on when the Main Light Switch is turned to HEAD or PARK.

The Lock Cylinder Lamps, Front Door Courtesy Lamps, I/P Courtesy Lamps and Dome Lamp are controlled by the Remote/Keyless Entry Module.

If the I/P Dimming Rheostat Knob is turned fully on, or if any door is opened, battery voltage is applied to the Remote/Keyless Entry Module. The activated voltage is then output to illuminate the interior lamps and other lamps as described above. If the Ignition Switch is not turned on within 45 minutes, the system will be deactivated by removing voltage from the Module to save the battery power.

The Vanity Mirror Lamps, Dome/Map Lamps, Engine Compartment Lamp, Glove Box Lamp and Trunk Lid Lamp are also controlled by the Remote/Keyless Entry Module. If the Hood, Glove Box Compartment or Trunk Lid is opened or the Vanity Lamp Switch or Dome/Map Lamp Switch is turned on, the respective lamp is on. If the Lamp is left on during the first 45 minute battery saver interval, the battery saver will recycle ONCE, leaving the lamp on a maximum of 90 minutes.

The Vanity Mirror Lamps, Dome/Map Lamps, Engine Compartment Lamp, Glove Box Lamp, Trunk Lid Lamp, Rear Reading Lamps, I/P Courtesy Lamps, Door Courtesy and Door Lock Lamps are all controlled by the Remote/Keyless Entry Module. If the hood, glove box compartment or trunk lid is open or the Vanity Mirror Lamp Switch, Dome/Map Lamp Switch, or the Rear Dome Lamp Switch is turned on, the respective lamp is on.
 
RE: Alternator question

........I go to Ace Armature in Pawtucket, RI for my alternators. They have the 130 amp NEW FORD G2 alt. for $130 after core return!!
Click to expand...

That is an excellent price for a NEW FORD alternator! I believe the list is over $360 for one!
 
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