Generator Still A Problem- Going Nuts

[KULTULZ]

what type of alternator is used? model and year?

Shown is a 1G ALT. They are very common in salvage yards.

The charging circuit harness will have to be upgraded from GEN to ALT.

Just stay away from GM one wires.

[KULTULZ]

1) Repair the ignition switch,

2) Full diagnostic sequence is in the Shop Manual,

3) A GEN has to be polarized after install and before starting car.

4) The voltage regulator is mechanical and adjustable. Check your manual.

[JohnG]

Jack, do you have a factory Shop Manual??

John

[ncbird]

simple tool

to do what was done with the headlight there is an easy tool you can make. Electrical supply and most box stores sell a light bulb socket with two wires with aligator clips. This is so an electrician can see from a distance if a circuit is hot. To adapt to cars all you have to do is go to a marine supply store (west marine or such) and buy a 12v DC bulb. Large boats use them in lamps etc and they screw into the standard 120v light socket. Voila a large test light and cheap. G

[simplyconnected]

Good suggestion, Grant.
I think all the RV stores have 12-volt bulbs, too. Just be careful you don't accidently put it in a regular 115-v lamp socket.

[simplyconnected]

...Just stay away from GM one wires.

YES! I agree. They don't have a GEN or 'sense' wire.

...A GEN has to be polarized after install and before starting car...

Actually, if your GEN light is working, that's exactly what it does when you first turn the key; it 'tickles' the armature with +12-volts as it shines. That small current produces enough magnetism to kick-start the armature as it cuts through the field lines of flux. The GEN light goes out when the generator produces more voltage, than the battery's voltage.

[jackbird60]

Hi John, I do have a 1960 Tbird Manual.

Jack

[JohnG]

hi Jack
Good!

Where are you at? Have you succeded in testing your VRs? Generator(s)? Have you narrowed down who does not work?? What can we do to help?

John

[vernz]

Have you checked the integrity of your wiring between the VR and generator? My 60 generator was not working last year. Using the knowledge I gained on this site, I finally found that one of the bolts that hold the generator together had worn through field wire insulation and grounded out the field wire inside the generator. Since you replaced your generator, that shouldn't be an issue, but the wire external to the regulator could be an issue.

Vern

[JohnG]

An example of a basic rule of old cars: assume nothing - take nothing for granted .

[Guest]

Generator light

It sounds like you have narrowed the problem to the generator not charging, but you should be aware that a charging light can come on for reasons other than poor or no generator output. That light comes on whenever there is a difference in voltage across the bulb. Normally this is when the battery is higher voltage than the generator output, but it could be caused by a faulty battery (absorbing current,) a short circuit, or a live wire grounding. I had a problem with a power window motor being stuck on and absorbing so much current that the light came on. Essentially the current is flowing in the opposite direction across the bulb.

I always use the screwdriver method as my first step diagnosing charging problems. Hold a screwdriver to the back bearing of the generator. (This works on alternators too.) If there is a strong magnetic pull, you are almost certainly charging. No or very little pull usually means the field is not energized so you are not charging.

If you have access to an ammeter, you can clamp it around the output wire and note the amperage. (Flow of current.)

If you haven't checked this, please do. I don't know much about your supplier, but more than one faulty generator seems very unlikely. Usually, they are bench tested; full fielded while driven by a belt connected to a motor before being released.

Good luck!

[simplyconnected]

Ted, this thread is 3-1/2 yrs-old. I'd be willing to bet, he's good now.

I like your troubleshooting methods for detecting magnetism.

Recently, my friend took his generator into an auto parts store for their 'free testing'. The employee had a box full of jumpers, but had no clue how to connect an armature or field. He had no clue as to how the gen worked at all. I find that as more time passes, more folks in the car industry really don't know (or care, sadly). Generators are becoming like the old 'growler' boxes; cool to have but not much use for one, now.

Olde tyme methods that used to be handed down to the next generation are nearly extinct.

Nearly everything on a generator or motor can be tested with a Continuity Tester, Jumper Wire, and screwdriver.

With one Continuity Light lead on the generator's ground:
A good field will produce a pretty blue spark if you lightly scrape the test light on the Field post.
If no sparks and the light immediately shines bright, it's shorted to ground.
The Armature post works the same through the brushes but remember to slowly turn the shaft to test all the commutator segments.
Of course, if you get no light at all, it's open.

I use the Continuity Light on big 460VAC motors as well. Normally, a meter will show a dead short no matter which way you test. A Continuity light between phases will hesitate (slightly) then shine. Pull the tester off, and here comes the telltale blue spark. Inductive reactance causes this because an inductor opposes changes in current, then the collapsing field produces counter-EMF. - Dave

[JohnG]

there is another simple area of generators that needs to be kept in mind: the brushes and brush holders.

As the brush wears, you get a build up of grime in the holder. Where the car is driven intermittently, the grime can harden, keeping the brush from moving freely and exerting the pressure against the commutator that is needed. A simple clean-up takes care of things. (same advice applies to almost any electrical device that has brushes - - motors included. Old toy trains.)