1969 Plymouth Fury, Starting/Ignition or electric issue?

[Kai2006]

That large post circled in the bottom of the picture you posted is battery hot and the output post of the alternator. It should match the battery voltage. Trace all of that wiring out individually with an ohm meter (and the battery disconnected!).
I bet you find a poor connection somewhere under the hood.

Thanks! It seems that this black wire goes directly to the bulkhead connector. But how is it suppliee with 12v?

 

[3175375]

Thanks! It seems that this black wire goes directly to the bulkhead connector. But how is it suppliee with 12v?

Thanks! It seems that this black wire goes directly to the bulkhead connector. But how is it suppliee with 12v?

I would have to check the schematic. I can do that later today.
You should have a factory service manual and the vehicle electrical diagrams are in there.

 

[3175375]

I would have to check the schematic. I can do that later today.
You should have a factory service manual and the vehicle electrical diagrams are in there.

FYI - I have a couple of the largest diagrams that these guys offer and they are helpful:

ClassicCarWiring.Com Home of the original color laminated diagrams

 

[Kai2006]

Ok thanks I have a good wiring diagram, but I still wonder if there is a direct connection between the battery and the alternator. As said we meassure 3v at the alternator but only when alle connectors are plugged in in the bulkhead. So it seems this feed runs through the car to the alternator?

 

[Big_John]

Hi John, at the alternator we meassure 3v. Strange. Are you sure at this black #12 wire it should be 12v?

View attachment 705187

Yes, there should be 12 volts at this point. Follow it back to the bulkhead disconnect at the firewall and it goes to #16 on that plug.

From there, under the dash, it goes up to the ammeter. The feed wire on the ammeter is red and that runs to #28 on the plug. Once that goes through the bulkhead connector it runs to the starter relay then through a fusible link directly to the battery.

So, I would start at the battery and the fusible link. How did you check the fusible link? You can't tell if it's OK by just looking at it.

 

[Big_John]

Ok thanks I have a good wiring diagram, but I still wonder if there is a direct connection between the battery and the alternator. As said we meassure 3v at the alternator but only when alle connectors are plugged in in the bulkhead. So it seems this feed runs through the car to the alternator?

Yes, direct connection through the ammeter from the battery to the alternator. And yes, the connectors would have to be plugged in or there's no connections.

 

[Kai2006]

Yes, there should be 12 volts at this point. Follow it back to the bulkhead disconnect at the firewall and it goes to #16 on that plug.

From there, under the dash, it goes up to the ammeter. The feed wire on the ammeter is red and that runs to #28 on the plug. Once that goes through the bulkhead connector it runs to the starter relay then through a fusible link directly to the battery.

So, I would start at the battery and the fusible link. How did you check the fusible link? You can't tell if it's OK by just looking at it.

Hi john, thank you. We checked the fusible link with a Fluke. And we meassure 12v before and after the fusible link. Also on #28 we have 12v. But not on #16; here we have only 3v.

 

[3175375]

Hi john, thank you. We checked the fusible link with a Fluke. And we meassure 12v before and after the fusible link. Also on #28 we have 12v. But not on #16; here we have only 3v.

Inspect the bulkhead connections and the connection to and from the ammeter.

 

[Kai2006]

Inspect the bulkhead connections and the connection to and from the ammeter.

We have found the ammeter and connected the two wires on it together. But unfortunately…..smoke! So quickly disconnected ground of the battery. Could be that we touched something on the steering column as half of the dash is dismounted now. But how to proceed wisely now?

 

[Big_John]

Hi john, thank you. We checked the fusible link with a Fluke. And we meassure 12v before and after the fusible link. Also on #28 we have 12v. But not on #16; here we have only 3v.

A partially burnt-out fusible link can still show 12 volts, but it won't pass enough current through it to do the job.

We have found the ammeter and connected the two wires on it together. But unfortunately…..smoke! So quickly disconnected ground of the battery. Could be that we touched something on the steering column as half of the dash is dismounted now. But how to proceed wisely now?

I would say that you have to figure out if you've shorted it. I will bet you have. Either that, or the ammeter was already burnt from a short.

I wouldn't connect any power to anything until you check for shorts.

 

[3175375]

A partially burnt-out fusible link can still show 12 volts, but it won't pass enough current through it to do the job.



I would say that you have to figure out if you've shorted it. I will bet you have. Either that, or the ammeter was already burnt from a short.

I wouldn't connect any power to anything until you check for shorts.

You are going to have to trace that hot wire all the way back to the bulkhead connection. You may want to start by disconnecting the bulkhead connections and look on both sides (engine bay and cabin).
You are going to have to be diligent in this.
You’ll find it!