Bulkhead Re-visited

[Omni]

I have been reading on this forum about the alternator gauge bypass with some interest. It seems that late 60's and early 70's era models are the most affected. I can understand why as the alternator wires were routed through the bulkhead multi terminal connectors. I have in the past had late '60's B-bodies that had melted connectors.
My '65 Newport however, has two separate solid connectors for the feed wires. They are encased in the bulkhead connector. The wires are bolted on both the dash and the under hood side. Would eliminating this type of connection in favor of a solid wire connection be that much better?
If eliminated, where would the 4 circuits that the existing black (R6 circuit) splices into under the dash get power from?
I like the modification which still leaves the existing gauge functional.
Thanks to all who respond.
Omni

 

[Ross Wooldridge]

That's what I did with my 66 T&C. My 66 Dodge Monaco 440 4-speed had that done at the factory. Having the feed wires go through the firewall separately with their own grommets to insulated terminal blocks is what they did for police cars to avoid the very issue created by running high amperage feed wires through spade connectors in the bulkhead connector. They were already well aware of the issue.

 

[HWYCRZR]

I believe old documents show that they did that for police cars as well. Somewhere I ran across a service bulletin on the subject.
I will have to look and see if I archived it somewhere.

 

[Big_John]

I have been reading on this forum about the alternator gauge bypass with some interest. It seems that late 60's and early 70's era models are the most affected. I can understand why as the alternator wires were routed through the bulkhead multi terminal connectors. I have in the past had late '60's B-bodies that had melted connectors.
My '65 Newport however, has two separate solid connectors for the feed wires. They are encased in the bulkhead connector. The wires are bolted on both the dash and the under hood side. Would eliminating this type of connection in favor of a solid wire connection be that much better?
If eliminated, where would the 4 circuits that the existing black (R6 circuit) splices into under the dash get power from?
I like the modification which still leaves the existing gauge functional.
Thanks to all who respond.
Omni

IMHO, the stock connections are pretty robust. As you say "The wires are bolted on both the dash and the under hood side". So no blade connectors to loosen etc.

As long as everything is clean, and in good shape... AND you aren't adding any high draw accessories, I'd leave it alone. I really don't think you are going to make any improvement by running a wire.

What you could do if you want to make the draw through those connections less would be to add a relay to the headlights as they are probably the most draw through that bulkhead. connection

 

[D Cluley]

The '65 version is much better than the '66 and later. Is it as good as solid wire with no connectors, probably not, but I will say that on mine, which had all sorts of electrical fun other places, the bulkhead was fine.

You definitely do want to check that the two ring terminals where the wires connect to the ammeter itself are clean and tight. That's where the melting & burning excitement starts.

 

[Omni]

Big_John
I have added headlight relays when I converted to Halogen. The relays receive fused power from the alternator stud.

D Cluely
It is a shame that Chrysler abandoned the '65 set-up. I guess the 'bean' counters won. Still the fact that these cars are still on the road after 50+ years is a testament to the engineering that went into producing them.

To clear up one item that has puzzled me, when one decides to reroute the amp wires (leaving the amp gauge in the circuit), the red wire would go direct to the gauge (as original). The black wire goes from the splice through the firewall to be joined with the alternator feed wire. Do I have this correct?

Thanks for your time
Omni

 

[bigmoparjeff]

Although the 1965 bulkhead is quite a bit more robust than the '66 and up, the system still isn't immune from trouble. I think it's wise to keep the high charging current from the alternator on the shortest path possible on it's way to the battery. I would make sure to have a fusible link on the wire to the alternator along with the power feed into the car.

I got a pile of '65 Chrysler parts some time back that included a bunch of wiring harnesses. Every one of them has at least one burned wire in it. This one was pulling a lot of current through the ammeter before something failed completely or the battery was disconnected. Otherwise, the car probably would have burned up.

Jeff

 

[Omni]

Jeff
I like the idea of the additional fusible link added to the alternator feed where it enters the bulkhead. I have already added headlight relays that are fused. The power comes from the alternator stud. That alone should eliminate considerable amperage draw through the harness.

Omni

 

[John Kirby]

I use a fuse instead of a link. And keep spares in the vehicle. Easier to repair on the side of the road. Fuse size depends on the accessories you have added over the years. The headlight relay upgrade is an excellent addition. The lights are much brighter when they get full alternator voltage. However, they still use the bulkhead connector when the ignition is off and the alternator is not spinning. So avoid using the lights when the engine isn't running.

If you have added electric fans, EFI, and other high current accessories. You really need to think about the current draw and how to limit what goes through the original firewall connections.

My approach is to have everything in front of the firewall on a power bus connected directly to the alternator using fuses for each circuit. The ignition, heater motor, A/C, wipers, washer and turn signals are exceptions to this. So are the idiot light connections. Everything else is run through relays. That cuts the current draw through the bulkhead connector to milliamps per connection. And ensures everything has full alternator voltage with minimal wiring voltage drop.

Doing it this way will make sure the ammeter swings in the correct direction when you turn stuff on. Connecting everything to the battery will cause a false charging indication when circuits are turned on.

The ammeter connections are also routed through holes with grommets to bypass the bulkhead. This is the most long term problematic electrical issue on these cars. Use soldered butt splices to make the under dash connections. And heat shrink them for reliable insulation. This is a critical safety area.

I do not recommend crimping terminals without also soldering them. The best solution I have found is a micro butane torch and solder. Use heat shrink tubing to seal everything. you need to know how to solder correctly. Lead based 63/37 solder with rosin core is what should be used. Do not use plumbing solder. Practice, practice, practice until you get it right. Once you do it will become automatic. The solder will flow through the joint like water when done correctly. If you have a quality high wattage soldering iron with a clean tip that will also work. Don't leave it powered up for extended periods, that ruins the tip.