1983 Buick Skyhawk 2.0l engine. Alternator will not turn on. Have bench checked both the battery and the alternator and both are good. Disconnected wiring and checked for continuity, all good. Checked wires for chaffing, all good. Cleaned all contacts and grounds. Ensured fan belt is tight. The fusible links (A, B, & G) associated with the starting/charging system are all good. With engine running and an external voltage meter connected, I have yanked and wiggled all wires from the dash to the alternator with no voltage change. Tried running a wire directly from the battery + post to alternator terminal 1 with no effect.
About 10% of the time the alternator will turn on, but only when the car is first started. When that happens it will usually charge for the entire drive. Usually, once charging, if I turn on the lights the charging will stop. Once, the charging stopped as soon as I opened the driver's door.
When I first start the car, if the alternator turns on, the volt meter does not immediately go to 14 volts. Instead it climbs from 12 to 14 in about a second or two.
GM service manual says to check for voltage at terminals 1 and 2 of the alternator when the key is turned to run with all connections attached. Manual only says they should read more than zero. Terminal 2 reads 12 volts, terminal 1 reads 3 volt. If I disconnect this plug, both terminals read 12 volts.
I understand the voltage on terminal 1 is what turns on the alternator. I suspect that the voltage or amperage going to terminal 1 on the alternator is being blocked or drained off somewhere, but can't confirm that. The Gages fuse supplies the voltage to terminal 1 and several other systems. Could a fault in one of those systems affect draw enough current to not allow the alternator to turn on, but not blow the fuse?
After driving home I noticed the volt meter in the dash reads low. With engine running I check battery voltage at the terminals with external meter and get 10 volts. Turn off engine and voltage goes to 11.5.
You will get some funny answers from some of these "experts " The symptoms suggest to me with out much doubt that the regulator is not doing its job correctly ,consistently.Iwould take it to an AUTO ELECTRICIAN and get it tested in situ.... there is only 4 things it can be , wireing ---battery---alternator-----regulator and of those the reg. is the only one that chops and changes. it will cost little for a sparky to check the reg ,. AND I WOULD LIKE TO KNOW THE OUTCOME
the post says this is 1983 model , that is 26 years old.how can that be under warranty ? assuming it is , if "gm" recalled a batch of vehicles ,it is not the dealerships responsibility to refute that . my suggestion is that you contact "gm" direct and get that sorted out first,otherwise you could void the warranty. now to the problem ----you need to bypass all existing wireing relativ to the alt.firstly wireing that age can and often does set up a resistance, also all earth connections need to be cleaned with emery paper..I find it hard to accept that 2 alternators are crook ,or two new batterys the starter is not a factor here ,as long as the terminals are clean. pick up apower soource and by pass all the alt wireing ,or best of all ,if you have someone with the same or similar car ,with thew same alt. swap them over and you will soon see if it is wireing or not. please get back to me as i am very interested ---"youdoit"
hi,i` m back .i just read steve 2257 or whatever he is `,s comments and i pricked up my ear because i am a west australian too . i dont like to say too much about these experts more than i said before but it is embarassing .in over 48 years of rac member ship, i have never heard of the rac testing alternators or any other components they are roadside assist ,prepurchase inspections towing and insurance,so they didnt test anything.anyone who would drive a car til the locking brakes put flat spots on the tyres is destined to go blindand i wouldnt be chasing him for advice.
HI MATE ,I HAD WONDERED A FEW TIMES HOW IT WORKED OUT . THANKS FOR LETTING US KNOW. I HAVE ONLY ONE CONCERN WHEN THINGS "COME GOOD" AND THAT IS WHERE TO START IF THEY GO BAD AGAIN ,BUT WITH A BIT LUCK AND A BLESSING FROM THE PATRON SAINT OF FIXING THINGS ALL MAY STAY GOOD ,IHOPE SO ,THANKS AGAIN FOR LETTING ME KNOW ALL THE BEST "YOUDOIT"
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For about $100 a GM dealership will put on a diagnostic. I reckon this may resolve at least where it is.
Good luck
I have a GM mechanic friend of family with all knows. He will rise to this challenge & give you some options. Carry a spare charged battery for a while until I get back to you.
I have car here in West Australia known to you as a Chev Caprice. Replaced alternator tested OK by GM, RAC, manufacturer & reconditioner.
Problem still there when on - car lights up & down(oncoming cars flashed back at me!), dash lights glowed light & dark & braking made Antilock go haywire as locking wheels to cause flat spot tires then let go. Warranty would not replace as tested OK - good eh? Replaced with reconditioned one is OK and now I have to replace all tires as lumpy ride. I suspect other damage caused as it had high V spikes.
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I think you have a bad alternator and battery. There probably isn't enough there to get and keep the alternator running. THe battery voltage should never be 10 volts when running - even with no alternator. Bench test is likely not suffient to test under the conditions you have in the car.
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Battery is new. When problem first started I had it checked and it was questionable so I replaced it. Did not affect charging problem.
Measured voltage at alternator is 12 VDC.
Internal regulator
Correct on funny answers. I've had a local "experts" tell me the problem is the blocking diode is open or the starter solenoid is shorted. One told me the fuse is blown and I would still read voltage with it blown.
I'm in a smaller town with mostly questionable mechanics. Most have you drop your car off and they'll get to it eventually, sometimes weeks later. There is a GM dealer, but their service department told me the recalls GM notified me of do not apply, even though my VIN fell in the recalled range. Next town with mechanics is 75 miles away. You can see why I do my own maintenance. There is 1 mechanic I use when the problem is beyond my capabilities. I still have to correct or have him correct his work.
The part store guy is a friend. Checked both battery and alternator. Regulator is inside alternator and was checked as well. All checked good. Due to ongoing problem, he "warrenty" replaced my alternator and battery. Problem continues.
Have wiggled and twisted every wire and connection I can reach both under the dash and hood. I know most wiring problems are at the connections, where the wires flex and get broken strands inside the installation. With that in mind, I trimmed back all the alternator wires and put new ends on them. No effect.
I disconnected the wire going to terminal 1 on the alternator and ran a wire straight from the battery + post to terminal 1, basically by passing all the wiring from the fuse through the gauge and blocking diode. Again, no effect.
I do suspect something might be siphoning off enough current to keep the altenator from turning on.
What problems external to the alternator can keep the alternator from turning on?
Just an update. I ran a wire straight from the battery to the terminal 1 on the alternator with no effect. Disconnect terminal 1 completely and the alternator turns on and charges. Isn't supposed to! Can't leave it that way as it can lead to an overcharge condition. Have also realized that the GM service manual I've been using is grossly incorrect on the wiring diagrams. So I am visually tracing all the wiring. Problem is no matter what I do, I have to be able to drive the car the next day. Good thing I own a battery charger.
SUCCESS!!
Not sure why?
Had alternator bench checked again and it checked good. Put it back into the car and took car to a mechanic. Checked good though all checks to include static loads and cranking. All wiring checked good as well. Car has been working good ever since.
Found a lot of little things, none of which should have caused my problems. Perhaps the total of them all did.
Appreciate all the advice and tips everyone gave me.
Thanks to all of you.
How old is the battery? Collapsed cell maybe.
internal or external regulator ? without being there i would go straight to the regulator
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