Question About Alternator

[goodnigh]

When I use the turn signal my headlights "flicker".

They go dim then brighter in sync with the turn signal.

That could mean I need a new alternator, correct?

New battery, battery cables, starter solenoid and

regulator recently installed. I think the alternator

is supposed to be rated at 65 amp so getting one

with a higher capacity, 100 amp, probably won't

make any difference. This is a stock Cleveland

in my '71 Grande with no add-ons like a 1000

watt boom box.

mike

 

[MotoArts]

If it were mine, I probably wouldn't worry much about it, if it's only dimming a little.

You're on the right track with the alternator output ratings. They are the "max" output figures. What the alt does at idle is something different. Probably if you add a few more RPM at idle (with your foot ~ 800-1000 R's) to test, I'd guess the light pulsing will either diminish or go away.

I did a G6 alternator conversion on my 5.0 car to get rid of the fire prone, stock G2 system. It's a fairly common mod in the '80s-90s Ford cars. Basically, it is the "one wire" conversion, but uses the smaller cased, bolt in alternator instead of the old giant GM style. Even though the new alt is rated for 95 amps, it does the same dimming thing with the lights since I have power pullies on it (small diameter crank pulley) that make the alt turn a small percentage slower than originally intended.

 

[goodnigh]

If it were mine, I probably wouldn't worry much about it, if it's only dimming a little.

You're on the right track with the alternator output ratings. They are the "max" output figures. What the alt does at idle is something different. Probably if you add a few more RPM at idle (with your foot ~ 800-1000 R's) to test, I'd guess the light pulsing will either diminish or go away.

I did a G6 alternator conversion on my 5.0 car to get rid of the fire prone, stock G2 system. It's a fairly common mod in the '80s-90s Ford cars. Basically, it is the "one wire" conversion, but uses the smaller cased, bolt in alternator instead of the old giant GM style. Even though the new alt is rated for 95 amps, it does the same dimming thing with the lights since I have power pullies on it (small diameter crank pulley) that make the alt turn a small percentage slower than originally intended.

This is an after market alternator that was on the car when I bought

it 7 years ago. The dimming is somewhere between noticeable and

dramatic. The other problem being I am itching to do some work on

the car.

mike

 

[IA Rider]

Check all of the lighting connections and the grounds. That should scratch the itch.

 

[RacerX]

When the lights dim like that, the alternator isn't picking up on the current draw at low enough RPM or quick enough. Usually a voltage regulator issue. If you have a volt meter, measure your voltage at the battery with the engine and all accessories off. It should be at 12.6 volts which is 2.1 volts per battery "cell". (12 volt batteries are made of 6 - 2.1 volt cells) . Then start the car and let the idle stabilize, the voltage at the battery shoud be at 13.8 - 14.5 volts now with the engine running. This indicates the alternator is putting out a charge current and raising the available voltage to the electrical system. If you don't see this voltage increase at idle, try revving the engine slightly to about 1000 - 1200 RPM's . If you now see the increased voltage, the voltage regulator is switching late (bad) or you might have under drive pulleys on the car. If you still don't see the voltage increase, this would indicate a bad regulator altogether or a bad alternator or wiring.

One old school test is to "TEMPORARILY" connect the F terminal at the voltage regulator to the A terminal with the engine running. This will put the alternator in maximum output mode and the connect wire and the alternator will get hot very quickly. You will see maximum voltage and current from the alternator by doing this and it will slow the engine down from the load.

DO NOT DO THIS FOR ANY EXTENDED LENGTH OF TIME. NO MORE THAN 10 SECONDS TO SEE THE ALTERNATOR OUTPUT!

Just ignore the amp meter in this diagram for our purposes.

http://image.mustangandfords.com/f/35545303+w650+h650+cr1/mump-1112-14-how-to-troubleshoot-your-charging-system.jpg

If the alternator works fine doing this, the voltage regulator is the culprit.

Personally if you just want a good, reliable charging system I'd convert to the late model 3G 130 amp alternator.

It fits in place of the early alternator for our cars, just change the pulley over and the wire plug is readily available.

I'm doing this on my '73 convertible.

Hope this helps, Curtis

 

[72HCODE]

to me it is a Voltage regulator issue.

Voltage regulators have different ratings and you have to match them to the alternator.

you didn't say what regulator you are using.

Stock Ford made a regular duty and a heavy duty voltage regulator

The stock was rated for the 55amp alternator

It also handled 38,42,45,55 or 61 amp alternators.

and heavy duty(A/C cars) got the 65 amp alternator with heavy duty regulator.

that was specific to the 65amp alternator.

personal experience: i did not know ford made 2 regulators, i bought a replacement thinking it was a stock unit. I had a 65 amp alternator. My lights flickered, you could see the dome light and headlights flickering noticeable at idle rpms. later i found out about the 65amp alternator and 65 amp regulator and changed over. I got a defective 65 amp regulator and had to return it for another one, that one worked and no flickering lights.

 

[goodnigh]

I know it is not the original alternator in the car now, original wiring probably.

Here is the new regulator, how do I tell if it is heavy duty? The car came with A/C.

mike

 

[72HCODE]

that is the standard duty regulator, repop also.

D2AF-10316-AA is the 65 amp unit.

http://www.mustangsunlimited.com/itemdy00.asp?T1=103168+01

you have other options as well, you could get a modern regulator that is solid state and then put the blue cap over it if you want it to look oem correct.

 

[goodnigh]

that is the standard duty regulator, repop also.

D2AF-10316-AA is the 65 amp unit.

http://www.mustangsunlimited.com/itemdy00.asp?T1=103168+01

you have other options as well, you could get a modern regulator that is solid state and then put the blue cap over it if you want it to look oem correct.

I will probably go with one of solid state models, I don't know what

type of alternator is in it now. That may fix the problem or I need

a new alternator.

Thanks.

mike

 

[Jeff73Mach1]

Headlight switch needs replacing in almost all of our cars if it hasn't already been done. . . just saying

 

[goodnigh]

Check all of the lighting connections and the grounds. That should scratch the itch.

If I really wanted to scratch that itch, I would replace the entire wire

harness. I bought a complete headlight to tail light harness to fit

my car and everything in between. Sent all 15 pounds back to

Midlife and he complete refurbished and taped the whole thing.

Got the harness from Don of OMS. Midlife sent everything back in

five separate bags all labeled with connections labeled where

everything goes.

mike

 

[Totalled]

Take a picture and post it of your alternator.

 

[IA Rider]

Check all of the lighting connections and the grounds. That should scratch the itch.

If I really wanted to scratch that itch, I would replace the entire wire

harness. I bought a complete headlight to tail light harness to fit

my car and everything in between. Sent all 15 pounds back to

Midlife and he complete refurbished and taped the whole thing.

Got the harness from Don of OMS. Midlife sent everything back in

five separate bags all labeled with connections labeled where

everything goes.

mike

Sounds like you are doing things the right way. Good luck with dimming light issue.

 

[goodnigh]

Take a picture and post it of your alternator.

Here ya go, thanks for the info.

mike

 

[John J]

that is the standard duty regulator, repop also.

D2AF-10316-AA is the 65 amp unit.

http://www.mustangsunlimited.com/itemdy00.asp?T1=103168+01

you have other options as well, you could get a modern regulator that is solid state and then put the blue cap over it if you want it to look oem correct.

I will probably go with one of solid state models, I don't know what

type of alternator is in it now. That may fix the problem or I need

a new alternator.

Thanks.

mike

I had that problem and went with a solid state model instead of the old style mechanical regulator and that stop the flickering. Rock auto sell them. Here the link.

http://www.rockauto.com/catalog/moreinfo.php?pk=1352980&cc=1132995

John J

 

[Totalled]

That's a motorcraft alternator. Looks like a stock replacement. If you believe the stamping on it, it's a 75 amp unit.

 

[RacerX]

That casting number, E9SF-BA is a 1989 alternator, 75 amp unit. Originally on a T-Bird or Cougar (If I recall the 3rd digit of the part number correctly, "S" is T-Bird). Use that information to look up and match your voltage regulator.

 

[rutkak]

It's hard to believe so many folks still have the VR in system. First and foremost I'd upgrade to a 100A 1-wire alternator and remove the VR since the newer models are internally regulated.

Another way to scratch your itch is to put your headlights on their own relays right to your battery. When I did it I noticed my dash and head lights were incredibly brighter. Well, my headlights were brighter because I put in H4 Halogens but my gauge cluster no longer had juice getting sucked away through the headlight circuit.

KR

 

[rocket366]

When I got my 73 strange lighting issues were going on for instance with headlights on the blinker bulbs

wouldn't blink and other crazy things.

Wire brushing the chassis harness ground connections front and rear cured all!