First off I am very new to the idea of using a forum but thought I would give it a try anyway. Two days ago I noticed when I turned the headlights on there would be a dip towards the D on the guage labeled alternator. Normally it settles in the middle all the time may fluctuate a little bit when using the power seats but has always returned to the middle. Tonight while driving the headlights shut off completely, the high beams still worked and after pushing them on and then off the headlights were back but after about 5-10 minutes went out again. The high beams remain working and also the tail lights remain lit. Any ideas or suggestions greatly appreciated.

 

There are several areas of concern that applies to ALL older Mopars

The bulkhead connector may be corroded/ loose/ heat damaged, especially the main battery feed and the charging lead from the alternator

The alternator may or may not be putting out full output, or---

if you have upgraded to Halogen headlights, they draw more current than original

Older Mopar alternators are not known for good performance at low RPM

The headlight switch, connector, and dimmer switch and connector may have problems

The high and low beam feeds through the bulkhead may be less than good

And the connections "up front" at the headlights and headlight grounds may be less than stellar

AND headlight switches have a circuit breaker built in which can become weak over the years.

PLEASE read this excellent article from "MAD electrical:"

http://www.madelectrical.com/electri...p-gauges.shtml

which came from here

http://www.madelectrical.com/

Look especially at the diagram posted in that article.

Notice on the black lead on the ammeter the "welded splice?" This is a big factory splice taped up in the harness under the dash. This comes right off the ammeter circuit and supplies UNfused power direct to the headlight switch, ignition switch, and a couple of other places

NOTE that the HEADLIGHT feed goes through the breaker ON (in) the headlight switch THIS CIRCUIT ONLY powers the headlights, NOT the park/ tail or instrument lamps

So you light switch has THREE separate circuits

ONLY the headlights on one circuit

The TAIL PARK lights on the second supplied from a fuse in the panel

ALSO powered from the TAIL circuit is the DASH LIGHT DIMMER circuit. NOTE that the power for the dash / instrument lamps comes OUT of the light switch dimmer control, and THEN goes to a separate small fuse in the fuse box. THIS IS the only circuit wired this way, IE fused after a switch.

So to sum up:

You may have a damaged alternator, IE one bad diode, etc

You may need a larger alternator

You PROBABLY need to address some of the wiring concerns above

You would do WELL to consider installing headlight relays under the hood which takes the load off the headlight switch, the dimmer switch, and the bulkhead connections

 

Thank you for the advice now I have a starting point.

 

Post back when you get deeper into things. You have a wiring diagram/ service manual?