I'm really confused with this: I had posted a message about going through 2 starters in one week. Well, the starter is fine. I know I have an electrical problem on my hands, but I don't know where to source it.
I can't start the car
Any accessory I turn on (lights, blinker, push the brake pedal down) causes my interior light to dim completely and then return to normal brightness after about 20 seconds.
I've replaced my starter relay, BOTH battery cables, ballast resistor, and voltage regulator.

Can someone please tell me what's going on here. I'm really frustrated by this, and the car's other problems. Even considering selling... but REALLY don't want to do that

Please help

MTV
http://pics.face-pic.com/pics/v/a/valiant.3.jpg

The power source for those acc. is the black wire running off the alt. It weld splices into your main harness before going to one side of the ammeter. If you have a lot of resistance in that wire due to corrosion, it may not be getting full power to your accessories.
I would use a multimeter to see how many volts you are getting at various points in that wire. Trace it all the way back to the main harness. Also, if yours is like mine there is a plastic connector on this wire about halfway across the firewall. The metal connectors in this piece are really subject to corrosion.
I redid mine after looking at the wiring diagram at MAD Enterprises. I run a 10ga straight from the alt to main harness and use about 2 inches of the old wire to do a soldered connection. Then I bypassed the ammeter and connected a 10ga to the wire on the ammeter side of the main harness, that went straight to the starter relay. On both the 10 ga wire, I drilled through the bulkhead connectors to eliminate the spade connectors, which are another source of resistance. Then I hooked up a volt meter. No more dim lights. Hope this helps.

The dome light being dim could be a bad ground or a bad voltage feed.
The no start problem reminds me of a bulk head connector problem I had
with my 70 duster. On damp mornings there was NO dome light and NO start. The firewall bulkhead connector had a corroded terminal in it.
After cleaning it up and getting a good connection (adding some silicon
grease to prevent corrosion) all was well. - So all that being said I second
the opinion the bulkhead connector needs to be looked at.

After talking to a co-worker, I've decided to check my negative ground first. Right now it's grounded to the water pump (and has been for 2 1/2 yrs). Obviously, the aluminum ground could be part of the problem.

Umm... where's the BULKHEAD connector again? Is that just the main wiring harness on the firewall?


MTV

Is the square (rectangular) connector where the harness passes through
the firewall from the engine compartment to the passenger compartment.
If I remember correctly it would be just toward the passenger side of the
steering column at least on a '70 duster. Ma Mopar may have moved it
over the different model years.

Guys, those firewall connectors... Are they used in the interior of the car? Could I find replacement connectors say behind the dash of a junker, where it wouldnt be corroded? Or are they used only on that connector, and I am stuck searching high and low for a Canadian seller of those connectors???

YOUR ALUMINUM GROUND AT THE WATER PUMP DEFINETLY NEEDS TO BE REPLACED WITH BRASS AND USE A VALVE COVER BOLT.

THE BULKHEAD CONNECTOR IS SUSCEPTIBLE TO CORROSION AND I AGREE WITH THE USE OF ELECTRICAL GREASE. ITS IN YOUR BEST INTEREST TO DISCONNECT THE HARNESS AND INSPECT EVERY CONNECTOR INSIDE IT. THE METAL CONNECTOR INSIDE SHOULD BE AVAILABLE FROM A TELEVISION REPAIR SHOP, JUST MAKE SURE ITS OF THE SAME MATERIAL. BE VERY CAREFUL ON REMOVAL OF THE CONNECTOR FROM THE PLASTIC HOUSING, MOST ARE "LOCKED" IN LIKE THE MECHANISM OF A ZIP STRIP.

_________________
IS 40:31 gets me through lifes challenges.

Television repair shop???

So they are just a regular w-crimp spade connector with a locking tab on the back, is that it?

verify the style of connector by disconnecting the harness at the firewall and behind the dash. its hard for me to explain what they look like and until we get our digital camera hooked up in the computer, i cant send you an image. some look like a pin, some a blade. i havent looked at the one in mine yet.

if you can find a donor at a junkyard, remove it from that first.

most electrical connectors are common types used in an wide array of electronic items. i know the tv repair shop came as a , but, i
was an electrician for the military for 250,000 years. fact is, though not relevant to you situation, a record player needle can operate as a speaker. apply

_________________
IS 40:31 gets me through lifes challenges.

Or you could eliminate the connector and hard wire the circuits. Nothing beats a hard wired circuit for reliability. Reground that negative cable to the block and also run a 10GA ground to one of the bolts securing the radiator, be sure to scrap all surfaces down to bare metal and use toothed-star washers. Use high temp wire and solder/shrink wrap all spades and lugs. Radio Shack is not the place to buy these, find a industrial supplier or liquidator.