OK, Got my car all cleaned for the trip to Salam tomorrow and when i started it up to put it away my Gen. light was on. but my volt gauge was reading alittle over 14 volts. I just got back from getting the battery and alt. tested and both tested fine.And i have replaced the voltage regulator. Do i just have a light thats going wacko? Any thoughts would be greatly apriciated.
Volt Light If You Were Just Cleaning, I Assume You Were Under The Hood Also, Check To See If Perhaps A Ground Came Loose While You Were Cleaning Maybe, Or If Intact Remove, Clean And Secure-a Possibility-have Fun-wish I Were Going.
Well maybe its not to be. Got in the car alittle after 5 this morning Gen. light was real dim and volts were at 11.So i took the alt. off my other car now volts are back up there but Gen. light is real bright again
Actually, the light is telling you something. The GEN lights in our cars is actually a useful tool- it can tell you what's wrong Check two things- the hot wire to the alternator (this is a notorious GEN light indicator on my car) and the connections to the voltage regulator. Also make sure your engine ground strap is OK, just to be on the thorough side. The light being on half bright and full bright isn't a fluke, that's the way it's supposed to work. if you notice, it's half bright whenever you start the car, too. A half bright GEN light means one part of the system has a problem; a full bright light tells you it's another part. Don't panic, should be just a loose wire :TU:
Seems he has a little more than his gen light issue.He called me back from Salem and was having brake problems as well.I got him in touch with the Chicagoland bunch and they are trying to get him running again.I am headinbg to Salem tomorrow at 4 am and hope to see the problem is fixed.. Pat
The light on dimly is an indication of a bad diode trio. If I had to guess, I'd would guess that when you rev the engine, the light gets dimmer...If you're pulling the thing all the way out, take it to a local auto parts store and have it bench tested. If all tests are OK on the bench, then you know it's something else on the car.
I have to disagree a little. It happens whenever there is 5 volts going in one side of the light and 12 in the other. It doesn't have to mean a bad diode. The resulting voltage drop means a half-bright light. This also happens when you start the car. The light goes off when 12 volts goes in both sides, and comes on full bright when 12 volts is present on one side and less than 5 is at the other This is from the 1970 Chassis manual Not trying to be a jerk, just trying to help. I couldn't find the manual before, I found the two books in my shop last weekend ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 20-19 Description of instrument panel-Skylark [GS should be 100% identical] b. Genrator light indicator The red "GEN" warning light should light when the ignition is turned "ON" and before the engine is started; if not lighted [Buick's poor English here :grin: ] either the bulb is burned out or the indicator light wiring has an open circuit. After the engine is started, the "GEN" light should be out at all times; if the light comes on, the generator belt may be loose or missing the generator or regulator may be defective, or the charging circuit may be defective. With the ignition switch turned on (engine not running) current flow is through the ignition switch, through the generator light in the instrument cluster, in the "4" terminal of the regulator, through the lower contacts of the regulator (held closed by the spring) out the "F" terminal, in the "F" terminal of the generator, through the brush and slip ring, through the field, through another brush and slip ring to ground Before the engine is started, the generator light should glow about 1/2 brightness. This is because the voltage in the circuit before the light is about 12 volts, but the volatge at the "4" terminal after the light is about 5 volts. This makes the effective voltage across the generator light approximately 7 volts for about 1/2 brightness After the engine is started, the voltage put out by the generator immediately closes the field relay. This causes battery voltage from the "3" terminal to be present at the "4" terminal. Since battery voltage is present on both sides of the light, the light goes out. if the generator light comes on while the engine is running, the charging circuit should be tested at the first opportunity to determine the cause of trouble. See paragraph 68-9 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Now, he cleaned some stuff, and now the light's on he's had the alternator and battery tested and they are fine, and the regulator is new. I am pretty sure we aren't looking for a diode. Not that it is bad advice; it just seems like the wrong path to be following here In my experience (oh man do I dream about all the times I've had that light come on half bright while driving) it is a loose alternator belt, or a bad wire connection. Could be at the "F" hole but that is rare. What happens in my experience is that the hot lead to the alternator gets a bad contact. they are pretty bad designs, I always seem to spin the damn thing while tightening or loosenign the wire. In 9 out of 10 times it's been this wire that causes me trouble- I've had that gen light on half bright while driving probably 2 dozen times since 1989, my car's no trailer queen, it's a driver, a real driver rain or shine, even snow until 1997 the other 1 time out of ten it was the connection at the "F" hole in the alternator, and it was my old wiring harnesses's clip that ws the problem- i soldered in a new one. Once in all those times it was the connection to the volatge regulator, probably the "4" terminal as noted by the manual. I hate that connector, those things are a PAIN, and they never seem 'wrong'. I wiggled the connector and looked inside the car, the light went out, and I drove away Please, I'm not an expert on everything and I don't try to be. I've just had more charging trouble in these cars than anyone else I've ever met, and if the alternator and battery checked out, and he's got the correct new regulator, we are talking about a voltage drop across the light caused by a bad connection causing part voltage to be introduced to one side of the light. The light's telling you one thing- 12 volts on one side, 5 volts on the other. Check your wires, make sure they are clean and conductive, that the clips hold the wires in place correctly, and make sure your belt is tight :TU: I have the procedure here for using a voltmeter to check the system, but I doubt we'll need that. I'd lay down 10 bucks it's a wire. if you do need it, I'll be more than happy to type up the procedure
Well i'm still not sure what the problem is. But i did drive to car to salam. It was a 3 1/2 hour drive and my voltage gauge stayed between 13 1/2 and 14 volts . The car seemed to run fine besides the brake problem Pat had mentioned.
When you bring an alternator to Autozone to have it tested, does it have to be out of the car? Could I drive my car to Autozone and have the alternator tested while it's bolted in the car? Thanks
