Idle and Headlights

I have a 1776cc and recently I was driving at night and notice that at a stop the rpms start going down then starts to sputter and stall when the headlight are on. But when I turn off the headlights the rpms go back up (engine is warm). I have also notice that the gages lights get brighter as soon as I start driving. Any ideas of what I should look for to repair the problem.

It sounds like a voltage regulator problem. If you are running a generator it should be an easy and cheap fix. If you are running an alternator the regulator may be built in. It may be mounted on the alternator, not in it. It may be a battery problem. Is your battery accepting a charge? If not, it may have a bad cell or a short in it. If the battery is fully charged the car should not stall even with the headlights on at idle, even with a charging problem. Have it checked by someone with a meter, they should be able to tell you what is really going on.

Could be a bad ignition switch or might be the size of the coil wire in the wiring harness is too small and causing a voltage drop. This wire has a rather long path and should be large enough in cross section to suit the ignition requirements.

You could try a hot jumper wire from the large 12V+ connection on the starter to the coil + terminal and see if the problem goes away. If so, mount a 12V relay near the starter, use the original coil wire to trigger it when you turn on the ignition switch, and use larger diameter 12V+ wiring (since it's a shorter distance from starter to coil #12 or #14 wire should be OK).

I just got the battery checked and it is fine not I need to get the alternator checked and see I that is it. I will keep you posted. Thanks for the help

AJ,
You didn't say how they checked the battery. Did they load test it? It's easy to do. Disconnect the coil wire and take the caps off the battery. Turn the engine over while someone looks inside the battery. Don't try this without eye protection. A bad cell will bubble. A simple alternator check is the old tried and true disconnect the battery while the car is running. That will at least tell you if you have a charging problem. Good luck.
Ed

If you disconnect the battery while the engine is running I hope you don't blow the diodes in your alternator.

It sounds as though he may already have a blown diode, if the alternator output is low. It should certainly be checked with a multi-meter, if he has one.

I took it down to AutoZone and they tested the battery. They said that it was holding the charge.

Ok, It was not the Alternator or Battery it was the starter. After it would heat up the car would die and the starter would not work until it would sit for about 20 minutes. The starter was changed and the problem was fixed. Just letting everyone know. Thanks for all the help. I still don't understand why the RPMS would go down when I would turn on the headlights? Oh well as long as it is fixed I am happy. :)