QuestionThanks alot! I discovered it was the voltage regulator. I put a meter on it and tested the field circuit. The regulator was allowing 7-8 volts into the field circuit. I had a spare regulator, so I swapped it out and everything is working much better now. Any thoughts on what would fry a voltage regulator? By the way, I have a 60amp alternator on the car (the shop manual indicates a 46 amp alternator came standard from the factory.) Was it the higher output alternator that caused the regulator to fail. Ok, one more question and I will leave you alone. Do you have a preference regarding brands of voltage regulators (i.e. Standard, AC Delco, Napa, etc...)
Thanks for your time, Chris
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Have a '69 Charger. Alt gauge is always below "0" unless engine is well above idle speed. Examples: Engine idling, I step on brake pedal-alt gauge takes a nosedive. I put on lights with engine idling and alt gauge takes an even bigger nosedive. I have also blown the fuse to instrument cluster bulbs when the lights are on and I open the drivers door. I have changed everything I can think of-alternator, battery, volt regulator. Do you think I should pull the instrument cluster and inspect switches (headlight switch, panel lamp dimmer)? Would a bad switch like the ones I mentioned above cause a blown fuse or is the voltage limiter behind cluster failing? Bottom line: something is sucking the battery to the point where the alternator can't keep up, right? Thanks for your time. Chris
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The fact that the ammeter needle moves upscale as you rev the engine tells us that the alternator and regulator are working, even though it does not seem to be going as high as we'd like to see.
The first thing to investigate is whether the gauge is telling the truth. To do that, start the engine with the hood open and let it idle, get out of the car making sure nothing else is turned on and the window is open, then close the door.
Now, loosen one of the battery cables and pull it off the battery post. If the car keeps idling, you KNOW the alternator is supplying some current - the only question is how much.
To determine how much, first try reaching through the window to turn on the parking lights - if the engine still keeps idling, add more loads - try turning on the heater blower - if it can handle that on high speed without stalling, the charging system is in pretty good shape. Keep going down this same road - turn on the radio, the turn signals, and finally the headlight low beams. If it can handle all that wihtout stalling, it is in great shape. Try the high beams too. If it can supply all that without the engine stalling, your charging system is in superb shape, so relax about the rest of your concerns.
If the engine stalled as soon as you turned on the parking lights, or with the first load you added, the alternator is not putting out enough current, and regardless of what you have already replaced, there is a problem in the charging system.
I cannot guess where it might be, but the first suspect is the alternator itself, and the second suspect is the regulator. You can either take those back to where you got them and have them tested, or you can look for a bad connection on one or the other of those devices.
Your dash switches etc. should not be involved in this at all - none of them can directly affect how much current the alternator puts out.
The fuse blowing when you open the door with the dash lights on is a separate problem, and most likely a misplaced wire on the courtesy light circuit, which does involve the dashlight control, but that is a separate issue and will only send you off in another direction - save that one 'til later. Leave the blown fuse out and continue with the main problem now.
Now, back to the gauge. When the car is totally shut down, where does the gauge sit? If it is dead center, then I don't know what is going on - it's just out of calibration somehow. If it sits off to the discharge side of the gauge, the problem is in the gauge unit itself - you can get a new one (Year One) or perhaps you can take it out and fiddle with the needle suspension and get it to come to rest in the center of the gauge with nothing connected to it. These are very delicate, but with care you may be able to repair it by just persuading the needle suspension to bend a tiny bit.
Let me know what you find out and I'll try to help you further.
Dick
AnswerFor things like that, I prefer NAPA - and their premium line if they have more than one. Their "Silverline" products are priced to compete with the Kragen and Auto-zone type stores, and are just as shoddy, but their premium line products are as good as OEM stuff.
On your car, they will probably have an orignal electromechanical type and also a more modern electronic regulator - they are interchangeable, even though it may have only two wires instead of the original three - the third one is not needed. The guys in the MOPAR clubs report better results with the electronic regulators (less flaring of lights on high RPM, less nervous wiggles out of the ammeter). I still have the originals on all of my Chryslers - none of them have failed yet!
I don't know what would have caused your old one to act up - normally they either work or don't work. I believe the same regulator is specified regardless of whether you have the standard or the high output alternator, so I don't think that was the cause.
Dick
