1974 Duster total electrical failure, followed by quick recovery.

[cruiser]

Hi All:
Just had this happen today. After shutting off my engine (225 auto), the entire car went completely dead. Nothing. Having seen this before on another Duster, I immediately located the main battery feed connector behind the brake booster. This is a heavy gauge red wire with a plastic male/female connector. I jiggled this connector and immediately regained full electrical control. I next removed the battery negative cable, then opened up the plastic connector and cleaned the terminals with steel wool and electrical contact cleaner. It went back together and works fine now. I'm wondering if any FABO members have had this type of electrical failure before. If so, did you consider removing this connector and soldering in a short piece of heavy gauge wire to keep this from happening again? Seems like this particular connector has a history of trouble with a lot of cars, and the only reason that this connecter was put there in the first place was to facilitate the installation of the wiring harness at the factory. For this reason, I don't see any problem with eliminating the connector and soldering in a hardwired connection. What do you think?

 

[tonysrt]

I had a bad negative connection at the battery cable, but after cleaning terminals never a problem again. 74 Duster 318.

 

[Mattax]

Yes.
That is a later style connector for the fusible link. Also used with the optional heavy duty alternator wiring schemes in later years. The connector is designed for locking together.

On a standard '74 wiring, the other end of the fusible link goes into the bulkhead multiconnector. Check that too.

Lots of guidance this in other threads. Pay attention to what the ammeter is doing under various situations. High charging rates can cause the heating in battery feed/charge line connections. Otherwise you may simply be looking at oxidation or vibration or other long term environmental cause.

 

[Mattax]

Basic Standard layout is like this.
(Not shown is the '74 seat belt interlock wiring details.)

All the wires connected to the battery positive are always hot.
The fusible link is protection in case a main wire or item shorts to ground, it will melt seperating the battery from the short.

Ground shorts occassional occur in the alternator, when wires under the dash chafe, or wires under the hood get pinched or insulation burned through.

Wires labeled A come and go from the bAttery positive.
Wires R relate to AlteRnator
Q1 feeds the fuses that are always hot.
J1 feeds the key switch.
J2 wires are fed from the key switch run terminal.
J3 is the fed from the start terminal. J3 bypasses the ballast resistor because at start the system voltage is low (10-12 Volts instead of 14 Volts when the alternator is running).

 

[Mattax]

If the wires from the battery and alternator feeds go through a grommet in the firewall, then your car has one of the optional heavy duty wiring arrangements. Some of those have two fusible links. Cars with rear defrost grids had this arrangement.

With the standard wiring the bulkhead connector is a somewhat weak link.
Removing and cleaning and even repairing isn't that hard once you'r doing it.
Discussion about removing the connector engine side. question on the main harness plug on firewall

One of a couple discussions on cleaning here:
Cleaning bulkhead connectors

 

[cruiser]

Yes.
That is a later style connector for the fusible link. Also used with the optional heavy duty alternator wiring schemes in later years. The connector is designed for locking together.

On a standard '74 wiring, the other end of the fusible link goes into the bulkhead multiconnector. Check that too.

Lots of guidance this in other threads. Pay attention to what the ammeter is doing under various situations. High charging rates can cause the heating in battery feed/charge line connections. Otherwise you may simply be looking at oxidation or vibration or other long term environmental cause.

Yeah, as I mentioned, when the car was dead, I just twisted the red side of this connector and everything magically came back on. So it's definitely the connector. I've never had this happen when driving, though.

 

[Dana67Dart]

If one side is the fusible link wire it might not be solderable.

Some wires, like the rheostat wire in the gas tank sender are a type of wire that does not solder properly.

Perhaps a higher amp capacity connector (weathertite) properly crimped on would be the ticket.

Another solution would be to take the plastic ends and drill them out to fit an inline splice to pass through.

Then put the connectors on the wires use the inline splice to join the wires, goop it up with clear silicone and slide the two connector ends together over the splice.

Once the silicone cures. It will look stock but be a permanent connection

 

[Bewy]

I have had this happen with an Optima red battery. Engine dies...going down a hill. Bat voltage after coasting to a stop was about 7v. A few hours later, it was back to ~12v. The bat shorted internally, & then recovered. No more Optimas for me. I checked on the web & there many similar failures after production shifted to Mexico.

 

[RedFish]

They never actually had to put any type of connector at the fusible link. A ex Chrysler master tech I worked with at a local Ford dealership called it a service disconnect. Separate that and service anything inside the cabin and majority of what is in the engine bay without ever touching a battery terminal.
Ford would stack several fusible links at starter solenoid stud with nut. So Troy also called Chryslers service disconnect one of Chryslers better ideas (back when we heard "Ford has a better idea") advertising.