Alternator Woes...well maybe Options

[57lincolnman]

I have a '75 1.8L that seems to have a charging problem. The battery was recently replaced and tests at 12.2v. The alternator was replaced about 6 years ago and when tested checks out at spec. So does the voltage regulator. The headlights were just replaced with LEDs which are great and draw less current than the old 100w bulbs and really light the way. The alternator drive belt does not squeal but I do smell burning rubber occasionally. Without any load on the electrical system the volt gauge reads 13v consistently at speed and maybe drops to 12v at idle.

Here's the problem... when driving with the headlights on the volt gauge barely registers 12v and is on the discharging side. When stopped at a stop light at idle with the headlights on, the volts drops to 11v. If I use the turn signal while stopped and have the lights on, it drops to nearly 10v. The battery is seriously discharging here.

This has been a persistent problem for some time, but has become exacerbated since I recently moved to SoCal where stop and go (mostly stop) traffic is a fact of life. Has anyone experienced this problem or have a suggestion?

[pbanders]

If you have a new battery, and after driving for a while, you're reading 12.2V on the battery with the car shut off, then your alternator and/or voltage regulator and/or alt harness and/or alt light (etc.) are bad. A fully charged battery will read 12.75V. Not 12.6, or 12.5, but 12.75V When the car is running, you should be reading at least 13.5V to 14V.

The link below describes all of the tests you should do to identify which part(s) of the system is(are) faulty. I strongly suggest to anyone who is working on their charging system to read the info at this link in entirety. Good luck.

http://www.ratwell.com/technical/ChargingSystem.html