Is the bulkhead bypass for new wiring harness needed?

[Brentstella]

I have rewired my car from front bumper to rear bumper using the M&H wiring harnesses from Year One. I have made the AMP gauge bypass while I was wiring the dash, but I was wondering, is the bulkhead bypass from alternator to battery still needed if all the wiring is upgraded?
BTW, the car is a 1970 Cuda 440 six pack with Rally gauges if that matters.

[Dakota]

All the amp meter bypass does is take the dash gauge out if the circuit.  Unless you bypass the bulkhead connector too,  you'll still have the full current load going though the bulkhead connector.  Failure of that connector is a matter of "when" not "if".   Other options to take load off the connector include using relays for the high and low beam headlights (or switching to LED bulbs).  If you're using an electric fuel pump, electric radiator fans, or have a/c system, relays are good upgrades.   

I did my own modifications to my wiring but member @crackedback sells "plug and play" wiring kits for these changes.  I've seen nothing but compliments for his workmanship. 

[71383bee]

I have rewired my car from front bumper to rear bumper using the M&H wiring harnesses from Year One. I have made the AMP gauge bypass while I was wiring the dash, but I was wondering, is the bulkhead bypass from alternator to battery still needed if all the wiring is upgraded?
BTW, the car is a 1970 Cuda 440 six pack with Rally gauges if that matters.

I'm a bit confused on the question.  Do you mean that you have new harnesses in AND the bypass installed but wonder if the bypass is needed?  Is the bypass just inside the car and you are asking if the bulkhead is worth bypassing?  If that is the case then you still have the charging load going through 2 posts on your bulkhead which still is a bit of concern.  Is it necessary...that is debatable and as Dakota indicated the more you reduce load through relays and lighting upgrades the lesser the risk.  To be honest the ammeter wiring equipment from what I recall is pretty beefy compared to the bulkhead! I feel the bulkhead is the weakest link in the system to be honest and I think bypassing this is not a bad thing to do so if that is what you are asking I would say yes if it were me and my cars I would take the additional step and do it.  Which I have done actually to every one I've owned. 

[HP_Cuda]

Here ya go!!!

https://www.allpar.com/threads/taking-charge-tips-and-tweaks-to-keep-your-mopar-current.237043/

[Brentstella]

I'm sorry for the confusion. You are correct, I have bypassed the Amp gauge and I was wondering that since the harness is new do I need to bypass the bulkhead also, or did M&H make any upgrades to the bulkhead so this is no longer required?

[dodj]

Bulkhead bypass would be a good idea. From alt to battery or start solenoid.

[crackedback]

Oh the can of worms you can open regarding this topic!   

I'm not an ammeter fan.  Yes, I sell a charge wire for the cars if you are doing the bypass.   The bulkhead is really the weak link.  There have been ammeters that have shorted into an instrument cluster.  I prefer a voltmeter.

M&H does the harness to factory specs IIRC.  There is nothing that you can do to upgrade the OEM bulkhead itself.  Any bulkhead fixes to carry current are parallel wires passing through the firewall.

Plenty of ways to do it.  Your car, your choice.

[Brentstella]

Thank you, this is just the information I was looking for.
One question though, if I run a wire from the battery directly to the alternator, I assume that I would disconnect the factory connection that was at the alternator and tape if off so the load is not being delivered through the bulkhead still?

[anlauto]

If the car is all stock original, is it really necessary ? 

[dodj]

If the car is all stock original, is it really necessary ? 

IMO... yes,  definitely. Always make your stuff as reliable as possible.

[anlauto]

I would like to think added all new wiring is a step in the right direction. 

[dodj]

Thank you, this is just the information I was looking for.
One question though, if I run a wire from the battery directly to the alternator, I assume that I would disconnect the factory connection that was at the alternator and tape if off so the load is not being delivered through the bulkhead still?

More variations on thought can occur here. When you install the bypass wire from alt to battery, you relieve the heaviest current (battery charging) from the bulkhead connector so some people leave it there. Some people disconnect it as you suggest. Myself, I repurposed it. I pulled it back and connected it to the red wire that normally feeds the interior from the start solenoid. This way the interior power is fed through two wires, splitting the load on the bulkhead connector between the two.

[Brentstella]

This is the information I was looking for. For now I will remove the factory line from the alternator and replace it with the line running directly to the battery.
I'm also going to purchase a headlight relay kit from Crackedback once I can figure out how to order it.

[headejm]

@crackedback is on here. You can PM any of our members after you have 10 postings.

[72RoadRunnerGTX]

Yes, the charge circuit bulkhead terminals are, by far, the weakest link in the original design, they have been failing at high rates since these cars were new. The Packard terminals were/are not sealed nor designed to handle real word current loads on the charge circuit. The current reproduction harnesses do not address this issue, simple copies of the original harnesses. At a minimum these two terminals should be by-passed as the factory did for all fleet production and high output factory alternators.
I'll take the information from an ammeter over a voltmeter any day. Ammeters don't spontaneously short to the cluster. As with any circuit components/connections designed to handle some current, some care and maintenance is required after 50+years.