Battery light or alternator?

[Stainless]

I've owned 02087 for around 13 months now, and I don't ever recall the battery light working. This is sort of a spin off from this thread:
http://dmctalk.org/showthread.php?2929-Bad-battery-alternator-or-something-else&p=39992#post39992

I took a video of what my car does when I start it:

http://www.youtube.com/watch?v=qB2NpX4c_aA&feature=youtu.be

The battery light never comes on upon start up, and the car seems to run off of just the battery's power until the engine reaches around 2200 to 2500 RPMs. If I don't ever rev the engine, the car slowly loses power because the battery starts to drain, even with the car running. As soon as the engine is revved, the volt gauge reads a steady 13 and the car charges and runs fine until the next time the car is turned off. Then this cycle repeats.

In the other thread, someone mentioned that the alternator may just be getting old, but I'm wondering if this could also have something to do with the battery light never coming on. What do you think?

[Bitsyncmaster]

The alternator turns on the battery light but If I were you I would replace the light first. Or you can test the light by grounding the brown/yellow wire at the alternator connector.

[DMCMW Dave]

This is acting like a good alternator with a bad or disconnected battery light.

[David T]

You need to test out the light circuit from the ignition to the light to the alternator but my guess is the voltage regulator in the alternator is kaput.
David Teitelbaum

[dmc6960]

I'm going to second Dave Swingle's suggestion. Twice in my ownership I've had a bad connection develop to the alternator light. Both times the alternator would not charge until the engine speed revved above 2500 rpm or so. After that it was fine until the engine next shut down and restarted. Nothing wrong with the alternator in either case.

[Stainless]

I was going to tackle this project this weekend, but decided to order some parts to take care of other things while I'm in there, so this will be put off until the additional parts arrive. Ordered a trip reset shaft and the parts that go along with that since mine has been broken since I bought the car. I have had a box of LEDs for the binnacle lights sitting in my garage for many, many moons, so this will be a perfect time to put those in.

I assume that I can use a known good bulb from the binnacle back lights and put it in the battery light socket, and all the others can be the new LEDs, correct? I don't recall reading that the battery light was anything special except that it had to be a regular bulb and not an LED. I'm hoping that the battery light will then come on and the car will charge properly without having to rev the motor. If anyone has any other tips of things to do while I have the binnacle off, let me know. Thanks.

[jmpdmc]

The alternator/battery light is a #161 bulb while the general binnacle illumination is a #194 bulb. The 161 bulb has an amperage of 0.19 amps vs. 0.27 amps of the 194. They are different and I imagine cannot be interchanged in this application. The LED's look great almost everywhere else in the binnacle so I think you will like the results.


Jeff

[Stainless]

The alternator/battery light is a #161 bulb while the general binnacle illumination is a #194 bulb. The 161 bulb has an amperage of 0.19 amps vs. 0.27 amps of the 194. They are different and I imagine cannot be interchanged in this application. The LED's look great almost everywhere else in the binnacle so I think you will like the results.

Thanks for the info. Can I get a 161 bulb at any local auto parts store?

[jmpdmc]

At a Napa in Ogden, yes---http://tinyurl.com/89mlcyl

[Stainless]

Problem fixed. I replaced the bulb with a new 161 bulb. The light now comes on when the key is to the ON position, and the voltage meter goes right to where it should be without having to rev the motor to 2500 RPMs anymore. I also replaced all other binnacle lights with LEDs and fixed the trip odometer reset shaft while I was in there. It was a very productive evening! Thanks for all the help. I'm glad the alternator doesn't need to be replaced just yet. This was a $2.50 fix :)