76 possible electrical problem

[bhermes]

OK, with car idling 14.2V, with car idling and lights on 13.4V, with car idling and lights on and 2 pin plug disconnected 12.1V. This is all with the external regulator plugged in.

Reminder that with the external regulator unplugged at different rpms the voltage did not change.

I know that this issue should be resolved but it is not. It seems that everytime I do something I determine the oposite of what appeared to be the case before.

[beermanpete]

OK, with car idling 14.2V, with car idling and lights on 13.4V, with car idling and lights on and 2 pin plug disconnected 12.1V. This is all with the external regulator plugged in.

Reminder that with the external regulator unplugged at different rpms the voltage did not change.

I know that this issue should be resolved but it is not. It seems that everytime I do something I determine the oposite of what appeared to be the case before.

This seems to confirm that you have the correct alternator (externally regulated). Get a new regulator. If you are still wary about your (our?) diagnosis take the car to a mechanic and let them fix it.

[bhermes]

Can anyone explain how with the external regulator unplugged that at different rpms the voltage was regulated. If this makes sense then I am going to get a new regulator. It is just becoming very strange that every part I purchase for the car is bad. A few alternators and a battery and now a voltage regulator. I guess it is possible.

I have a local electrical car auto place that I am soon going to take the car to. I know for sure you guys are doing the best you can without having the vehicle in front of you and maybe I need to get an expert that can look at the car.

[beermanpete]

Can anyone explain how with the external regulator unplugged that at different rpms the voltage was regulated. If this makes sense then I am going to get a new regulator. It is just becoming very strange that every part I purchase for the car is bad. A few alternators and a battery and now a voltage regulator. I guess it is possible.

I have a local electrical car auto place that I am soon going to take the car to. I know for sure you guys are doing the best you can without having the vehicle in front of you and maybe I need to get an expert that can look at the car.

Your post from last night suggests no output from the alternator.

Will try the suggestion tomorrow. However, when I unplugged the external regulator and checked battery voltage and got the following;

1000 rpms - 11.6V

1500 rpms - 11.6V

2000 rpms - 11.6V

I thought this may mean that I have a internal voltage regulated alternator. A previous post stated that the alt output was proportional to the rpms.

When the external was plugged in I got the voltages changing with rpms and ranging from 14V to 18V.

Again I will try the suggestion to have additional data.

11.6 is the battery voltage with a load from the ignition, fuel pump, etc. without any charging from the alternator. It is steady and therefor seems regulated because the load is steady.

When the charging system is working correctly the battery voltage will be about 13.5 with the engine at idle and rise to about 14.5 when you increase the engine RPM. It will regulate to 14.5 at all engine RPM above idle.

[bhermes]

Going back through all of the posts and trying to put all the pieces together I think that my best option at this point is to assume I have an external regulated alternator and that the external voltage regulator is bad. I am not positive but at this point I am going to try and get the first external regulator returned and purchase the new external regulator. I guess I will learn quickly if the problem is fixed and the voltage stays under 15V at the battery. If not I will take the car to a electrical auto shop for further diagnosis.

I have learned a great deal from this post and I really appreciate everyone putting the time in to educate me and help solve my problem. I realize that this is mainly a forum to solve issues not educate so again thanks.

[5thhorsemann]

We learn from fixing eachothers problems, so educations are a direct result of these posts. I consider myself to be a very skilled mechanic, and find these threads very educational still.

[bhermes]

5thhorseman, thanks for the patience and your take on the forum. \

To all,

I bought the new voltage regulator and I am ready to install.

I got the part from NAPA and talked them down from $105 to $86. The person there told me that once installed they would not take the part back. Never the less I got the part.

The question here is as follows; should the car at idle be charging the battery (14.5V vs 12.5V). I am getting readings at or around 14.5V at idle and the person at NAPA said this is unusual and thought that I had some other problem other than the regulator.

Also, since I am getting 11.6V at all rpms with the regulator unplugged I am assuming that with it unplugged the alternator stops working. Any idea on how long a car will run without a working alternator? Just a curiosity question.

[5thhorsemann]

If you are seeing between 12 and 14 volts you are good to go, if it gets any higher than 15.5V, or lower than 12V you have a problem.

[bhermes]

Back to the drawing board.

New External Voltage Regulator and same problem.

Idle Voltage is about 14V and raises to over 17-18V at higher rpms.

Any more suggestions or time for big dollars at auto electric place.

[beermanpete]

I thought of a way you can test the alternator to see if it is internally or externally regulated. The following assume your alternator works correctly regardless of which type it is.

Disconnect the voltage regulator and the 2 pin connector from the alternator. Connect 2 light bulbs (12 volt, 23 watt, part number 1156), from the 2 pins on the back of the alternator (1 bulb each) to the positive battery terminal.

If you have an internally regulated alternator:

Engine stopped: The bulb connected to the L terminal will light, the other will not.

Engine running: Both bulbs will not light, battery voltage will be normal (~ 13 at idle, 14.5 volts at increased RPM).

If you have an externally regulated alternator:

Engine stopped: The bulb connected to the F terminal will light, the other will not.

Engine running: The bulb connected to the F terminal will light, the other will light but at about half brightness. The alternator will have some output but will not regulate (the battery voltage will rise with increasing RPM).

[bhermes]

Finally got to try the light bulb check with little to no success. I could not get the bulbs to light up. With the engine off I could not tell anything going on at all except a few sparks. With the engine on I still couold not get the bulbs to light but both wire leads got hot. Again not an electrical expert by any means but maybe gage wire was an issue.

Comments?

[beermanpete]

What bulbs did you use?

What wire gauge?

The bulbs should light up if there is enough current to get the wire hot. You might have a short across the bulb. If you connect the bulb across the battery it should light. Try that, carefully.