Well, all the lights on my car stopped working except the headlights, and when I turn on the high beams, they go out. It happened suddenly and It just doesn't make sense, the fuses are good, I checked them with a meter. I suspect it has something to do with the fact that I've been getting way too much voltage, like 16-19volts when the car is running, and I couldn't figure that one out either because it wasn't the voltage regulator... I just don't know where to begin, any tips? Maybe a ground wire somewhere? The book says about the main connections in the wiring harness, but I'm not sure where these are located. It is a 1968 Delta 88.

 

When you say the headlights, do you mean the parking and taillights, too, or just the headlights?
The headlights are protected by a circuit breaker inside your headlight switch - if that goes bad, then you need a new headlight switch - about $12 at any auto parts store.



DANGER WILL ROBINSON!

If you are running voltages that high, you will blow out all of your light bulbs, so that may be your problem right there.

Oh yes it is.

Begin by getting a new regulator.

After that, test all your light bulbs, then check back with us.

- Eric

 

I did replace the regulator and nothing changed, I think it may be because I am using a battery I borrowed from my boat and it has way less cold cranking amps. The parking lights, tail lights and brake lights do not work, it is only the headlights that work, even the dash lights quit. I will start checking the bulbs.

 

You mentioned in another post that you had a leakage current from the alternator, possibly a diode is leaky. Did you do some emasurements on it as I suggested? If not, take it off and take to a parts store that can check it.
Depending on how it has failed, there is a possibility it could be damaging regulators. Might as well remove it fromt he equation.
The boat battery is not an issue if it is 12V and the car starts from it.
The 16-19V will damage a lot of stuff, as well as over charge the battery until it is damaged by boiling the acid and warping the plates until they short internally. This can result in a possible burst - happened in my ford 30 years ago or so.
Get that alt checked.

 

All the bulbs up front are bad, tail light bulbs look good, but I'm sure they are not, they are pretty much welded in there so they are going to be a pain to get out. I never did get around to checking the alternator since I have been have been working on my truck a lot. Can they test it while it's in the car? It's time for inspection, so maybe I will just have the garage deal with it.

 

It's time for inspection, so maybe I will just have the garage deal with it.[/QUOTE]
garages love electric problems,they can spend hours and hours trouble shooting and you get to pay the bill.
removing those " welded" blubs will proberly cost about an hour labour each and you will have to replace the sockets when there done.

 

If I replace the sockets it shouldn't take long at all because I won't even have to remove the bulbs, I can just break them if they prevent the sockets from coming out. Yeah , I guess you are right about the garage, I will take off the alternator and get it checked, then once I get my voltage down I will replace those sockets and all the bulbs and then go for inspection.

 

Whoa there, lets not start breaking your housings and such. Generally if you spray some pentrant in there, wait a bit and give it a twist either the glass on the bulb will break, or it will come out. If the glass breaks use a needle nose pliars and peel it out. Then clean the sockets, unfreeze and straighten the wires, and lube the spring contacts. Then put a new bulb in, it's simple.

You do not want to run the car at 19v. Get your alternator and regulator load tested.

 

Yeah, all I meant was breaking the glass, I don't see them coming out otherwise but I will try.

 

Once the glass is broken, the metal is thin and can be peeled out with pliers. Been there done that. No need to replace the sockets, unless they are rusty hulks.

 

Back to fundamentals. First, the headlight circuit is COMPLETELY separate from the other light circuits. The fact that the high beams don't work can only be caused by either burned out high beam filaments, bad headlight grounds, bad dimmer switch, or bad wiring or connectors between the dimmer switch and the headlights. There is nothing else that could cause it.

The rest of the lights are activated by a separate set of contacts inside the headlight switch and run through the fuse block. You'll need to open the wiring diagram and just trace the circuit back from the headlight switch.

 

If it is an overcharge condition blowing out the lites, I would suspect the battery or a bad body ground. Start with a good battery, you seem to need one anyway. If it is the alternator which I doubt, it would be a shorted field wire to a hot wire or a grounded rotor, both fairly uncommon.

 

I'm getting 40 volts ac on the back of the alternator, is that normal?

 

No.

That would be bad.

The output post should have about 13.5-14.5VDC on it.
The rectifier should have filtered out the AC.

Sounds like you've got a shorted rectifier diode or two.

- Eric

 

my truck has like 32 volts and everything works fine... I'm going to take the alternator off and get it tested.

 

I think we need to get pictures of exactly where you ate taking these measurements from, and what your alternator and regulator look like.

I also think you need to confirm that your meter is functioning properly.
Significant AC current flow in a DC system like this can overload the alternator and damage other components.

- Eric

 

I have to agree with Eric. Something ain't right. No way your truck shows 32 volts with no problems. Lights would be extremely bright and blow out shortly. However, your problems with the car does point to over-voltage.

 

Are you possibly using an induction meter to get the 40 and 32 volts ac? A meter that has a clamp to go over the wire. Or is the reading you found derived by using probes? If it is a clamp type induction style, you may actually be reading ripple voltage and the figures you give for both vehicles indicate a good alternator as far as the rectifiers and stator are concerned. Please respond as I am very curious about what is actually going on and I think we may need to go back and find the DC overcharge problem.

 

It was a regular multimeter from harbor freight with the probes. I was measuring the hot wire on the alternator with the ac setting but the guy at the garage said it's dc at that point. Anyway it apparently was the voltage regulator, once I actually mounted the new one (remember the old one was new too) it stays under 15 volts at the battery, and the drain went away! I ended up replacing the sockets in the tail lights, but now they work. Now the biggest problem is the headlights, I replaced 3 because one still worked but now I get nothing on low beams and on high I get 2 on one side and one on the other, maybe I should replace the one I didn't... It started raining and got dark so I quit working on it but I guess it's drivable now which is good because my truck won't hold transmission fluid so the car is my daily driver again. Thanks for your help guys, I can't believe every single bulb burned out! I was lucky the battery didn't explode or anything, I think it being a marine battery really helped cause apparently they are made not to leak etc.

 

Oh yes it is.

 

Sometimes it is what it is.

And there's no doubt what it is.

- Eric

 

Guys:
Recently repaired the pins in a 66/67 cutlass for a friend. If yours are loose or missing, I can possibly help. GM had a poor design for attaching them to the board w/ swedged over tabs that are very weak. If I can help , let me know.
Thanks RonFX

 

Headlight problem is just corroded connectors.