Lost all power need help

[Bparks]

So I just bought a 1970 Duster 340. I took it out today for the first time since I purchased it and I lost all power. I got on it a little bit then everything shut off. I have no lights no nothing. What do you guys think the problem is? I think it might be the fusible link? This is my first classic car so I'm not really sure. Any help would be great. Thanks.

 

[krazykuda]

So I just bought a 1970 Duster 340. I took it out today for the first time since I purchased it and I lost all power. I got on it a little bit then everything shut off. I have no lights no nothing. What do you guys think the problem is? I think it might be the fusible link? This is my first classic car so I'm not really sure. Any help would be great. Thanks.

Check the fusable link for any "soft" spots... Then check the bulkhead connectors at the firewall both inside and outside to make sure that they did not loose their connection...

 

[AJ/FormS]

his can also happen with BOTH a dead alternator and a bad battery connection. Hardly likely but worth mentioning.

 

[65wgn440]

Ignition switch connector at steering column ?? Had similar issue on '71.

 

[Bparks]

Thanks guy, I figured it out. It was the fusible link. I created a small jumper bypassing the link and everything works. Now Just need to figure out how to get the link out of the bulkhead connector, any tips or tricks?

 

[67Dart273]

Go read the article at MAD:

Catalog

Even if you don't do that mod, it points up some of the problems with the bulkhead connector

Then "if you dont" wander over to MyMopar and download a free factory service manual.

So far as getting the terminals out, the male ends have a tang on the side, you squeeze them with small needle nose, or pry gently with a small screwdriver. The female ends have a tang you can release with a small screwdriver

Those are known as "Packard 56" terminals

 

[65wgn440]

I have completely removed terminals from that cavity and ran fusible link wire intact through bulkhead connector into interior, then spliced in. Sealed cavilty with black rtv. Terminals just need to be pinched, then pushed out.

 

[Mattax]

So I just bought a 1970 Duster 340. I took it out today for the first time since I purchased it and I lost all power. I got on it a little bit then everything shut off. I have no lights no nothing. What do you guys think the problem is? I think it might be the fusible link? This is my first classic car so I'm not really sure. Any help would be great. Thanks.

It probably happened too fast, but on a stock system if the ammeter swung over to full discharge that's a warning that fusible link will likely fail in a short time.

No lights pretty much means no power from the battery.
Engine off - Key off or key on, when the headlight switch is on the ammeter should show battery discharge.
Here's summary about Understanding Charging Systems with Ammeter

Anyway. Start with the battery.
Check the cable connections - both ground and positive.
Then the most basic check with a multimeter is voltage (with no load) from positive to negative.
If it 's under 12.5 Volts, see if it can be charged up.

Take the multimeter and leave the negative clipped to a ground,
measure voltage at the starter relay, then the back of the back of the bulkhead connector where the feed wire (witrh the fusible link) goes.
You can also check the BAT terminal on the back of the alternator. They all should be at battery voltage if there are no breaks.
If so, turn on the headlights and check again. Once there is current flowing, then weak connections will show up as voltage drops.
However I think you'll find the problem before having to do that.

The diagrams on the page I just linked should make it clearer what I'm referring to.
The next page has an overview of fusible links
Fusible Links in Charging Systems with Ammeter

 

[Mattax]

Now Just need to figure out how to get the link out of the bulkhead connector, any tips or tricks?

First. Please read my previous reply!!!! A burnt fusible link indicates something is seriously wrong. It's the only protection between keystuff and the 300 to 700 amps in the battery.
Trouble shoot with a circuit breaker instead of a solid wire.

Removing the link:
Disconnect battery.
Gently unhook the top and bottom of the bulkhead connector with the link. Remove the connector. Take your time.
Use a terminal removal tool (or a cotter pin or thin screw driver) to depress the barb on the terminal & remove.
The barb is visible in the lower left picture posted here: Lost all power need help

Replace with either a Chrysler style (shown above) or the packard 56 female terminal. This wire carries all power when the alternator is not running, and will sometimes see 30 or 40 amps for brief periods. So this is an important connection to use the correct terminal for the wire size etc.
(Detroit Muscle makes the foam seals that go inside the connectors)

Here's a close up of open barrel crimp jaws (pics borrowed from civilianjeep bb: BASIC WIRING 101, Getting You Started! - JeepForum.com)

and a female terminal crimped

To remove the females, use a flattened cotter pin, tiny screw driver, or the tool they make for it to depress the tab while pushing it out. (The double prong version doesn't work well on the some of the mult-wire connectors like the bulkhead. The second prong gets in the way)

To remove the male terminals, you have to squeeze the open part while pushing it out.

The terminals can be often be had at the parts stores. If not, you can mail order from Waytek Wire, terminal supply Company, etc. Or you can sometimes get a few from someone here who has more than the need.

 

[67Dart273]

NOTICE!!!!! The female Packard 56 pictured above MAY NOT FIT your Mopar connector. Most older Mopars MUST use the type where the sides are "curled in" as I posted earlier, and not the type with the tab folded "over the top"

 

[Mattax]

NOTICE!!!!! The female Packard 56 pictured above MAY NOT FIT your Mopar connector. Most older Mopars MUST use the type where the sides are "curled in" as I posted earlier, and not the type with the tab folded "over the top"

View attachment 1715178267

I agree, the ones you pictured are the type I'm always finding in the orginal harness (60s anyway). Didn't know there were fit issues with the flat spring ones on some connectors, but I'm sure you're right.

 

[67Dart273]

I have parts of a 73? harness and have found the "over the top" connectors in some of the interior under dash stuff, don't remember specifically what.

 

[Bparks]

Hey guys once again thanks for all the help, I really appreciate it. I read the mad article that 67Dart273 posted and upgrading to the volt meter seems like the best route. After looking under the dash the previous owner had already bypassed the amp meter. I thought it was working because the needle stayed in the middle. Mattax, I check everything with a multimeter that you suggested and everything checks out ok so far. Like you said I decided to stop testing until I get the replacement fusible link. I'm hopping it burnt up because its the original link. Maybe I'll do what 65wgn440 suggested and bypass the bulk head terminal until I can do the full upgrade.

Another interesting note is my ballast resister was also broken. Not sure if that was a coincident or if I do have more electrical issues. The positive thing is I learned a lot about the car over the weekend. Thanks guys

 

[Mattax]

May or may not not be a coincidence.
Points and Chrysler type electronic ignitions both use the ballast resistor as part of the run circuit. In other words, power to the ignition goes through the ballast when the ignition switch is in the run position.
In the upper left of the 67 Run charge Diagram the dashed blue line is the Run power. Then it goes through the resistor to the coil.

Yea well I've been reading too many badly done ammeter bypass threads so I won't even begin to guess what happened in your case. That's one of the things I don't like about the MAD suggestions with respect to the a-bodies and the full size jeeps. It's why I reprinted Nacho's stuff, with some editing better english. LOL, and now some additions. IMO its clearer on troubleshooting and also more mopar specific. Just finished dealing with a 'bypass' thread in the IFSJA forum some guy innocently revived. It did just the opposite - putting all of the current except charging through the ammeter - but it had nice pictures. Sorry, getting OT here. Point is you'll have to check the routing to see if it makes sense.

No it will not burn up because its an original link. If its been in an environment where it got oxidized (green stuff on the copper) or physically damaged, then it would fail more easily, but not age alone.
It will melt because too much current is being drawn through it.
* This could be because of a short, which is its job.
* This could be because its carrying more current, for longer lengths of time, than it was designed for. It gets really hot but doesn't fail. Then repeat the next time, and repeat until it does fail.
For example wiring EFI equipment onto the battery terminal forces the fusible link to carry all the current for recharging the battery - done in a few minutes, plus all of the current for the fuel pump, injectors etc. full time. Either one of those alone might be ok. Together that 16 gage or even 14 gage wire becomes resistance.
That's the point of the bottom diagram on Fusible Links in Charging Systems with Ammeter

You can use a circuit breaker for testing and save the fusible link for actual use.