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?

[Dave_Darling]

The way the gauge is wired into the electrical system was done more for ease of manufacture and low cost than for accurate measurement of the state of the charging system.

In other words, they all do that. (Except possibly if all of the electrical connections are absolutely perfect, which probably lasts all of a half-hour.)

Treat the gauge as "entertainment". Or get to know how it behaves and then only pay attention if the behavior changes. To get an idea of the actual health of your charging system, use a volt-meter across the battery posts themselves.

--DD

[drem914]

The way the gauge is wired into the electrical system was done more for ease of manufacture and low cost than for accurate measurement of the state of the charging system.

In other words, they all do that. (Except possibly if all of the electrical connections are absolutely perfect, which probably lasts all of a half-hour.)

Treat the gauge as "entertainment". Or get to know how it behaves and then only pay attention if the behavior changes. To get an idea of the actual health of your charging system, use a volt-meter across the battery posts themselves.

--DD

Thanks Dave. At least I can take that off my to do list of maintenance issues for the car. (IMG:style_emoticons/default/beerchug.gif)