Driving last night, all lights go out, iwds almost engage, airbag and emergency lights come on, engine quits. Pull over as this is happening, passer by give me a jump, I make it home. I trickle charge for 4 hrs. Measure across +- and get 12.3v with engine off. Start engine , measure across +- and get 12.3, holding it on there for a few min, I observe this reading drop steadily to 12.0 volts. I am thinking alternator ...?

 

Well, you're certainly not charging at 12.0-12.3V with the engine running. But, maybe, instead of the alternator itself, how are the connections? Check the connections at the battery terminals, the other end of the negative battery wire, the connections at the alternator, and so on.

- Jack

 

I removed, cleaned and reinstalled battery connections. The other end(s) feel/appear ok. I didn't remove any of them just a visual and wiggle. All seem ok.

 

OK, I THINK, but I've never had it done, that automotive stores like Autozone, etc., can check your alternator. I think it can be done in the vehicle, if you can get it there.

Other members probably have better advice on this option.

- Jack

 

Jack and Janet, thanks for your advice. I am pretty much convinced it is the alternator. With engine running and no other electrical on (lights, A/C-fan, etc) the volts on my scangauge II reads 12.2. As I turn on lights: 12.0, as I turn on a/c: 11.8. Even revving up to a steady 1500+ has no voltage increase on scangauge.

 

Parts stores can test both the battery and alternator in the parking lot.

 

I'm going to try and make it to auto zone, to be sure..

 

It's obvious that the alternator isn't charging and that the battery was run down completely, but it's not obvious if the alternator has failed.

Fully charge your battery before leaving. Travel so you use the least possible electrical power. Daylight, no lights, no stereo, switch AC to OFF, roll the windows down a bit for ventilation, etc....

You will be running all the mandatory electrical systems off the stored battery power, so preserve it.

 

Stay OUT of the zone.

This caption describes the best way to test a battery:



This describes how most modern alternators work:



Yours probably has an internal VR, and it may also be PCM-controlled, but some of that information still applies.

 

went to the zone ( i hate that place), they couldn't test because the battery was too low... The battery I have is over 4 years old. I replaced the battery. Same results and readings as before. This morning I removed the alternator and brought it to a local re builder. It will be ready tomorrow.

 

Brushes were completely shot. Back to 14.2. Thanks for all the help!