Adding on 2 circuits

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1969dodgedart

1969dodgedart

Big Block 440
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Ontario,Canada
Just trolling for information and ideas on incorporating two electrical items into my car ie: stereo ( amp etc ) / electric fans ? Already have a plan just want to see what other thoughts are out there .
 
I just did this, 4 keyed and 3 hot. I used a Painless wiring kit that came preassembled and included a relay and circuit breaker. I mounted the fuse block in the glove box behind the heater box. The only thing you need is a source to trigger the relay otherwise completely independent of the stock system. You can also source the fuse block and pins and build you're own too.


Painless Performance Fuse Blocks - Free Shipping on Orders Over $99 at Summit Racing
 
1969dodgedart said:
Just trolling for information and ideas on incorporating two electrical items into my car ie: stereo ( amp etc ) / electric fans ? Already have a plan just want to see what other thoughts are out there .
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Check the amps for both the fans and stereo you want to use. You may want to also upgrade you alternator to a highter output to keep up with the load increase.
 
1969dodgedart said:
Upgraded the alternator already to a 90 amp , will check the draw of those fans.
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BUT HAVE YOU fixed the inherent wiring issues? The ammeter / bulkhead connector issue/ circuit. The factory wiring does not have much headroom for heavier accessories CERTAINLY NOT 90AMP ALTERNATORS
 
67Dart273 said:
BUT HAVE YOU fixed the inherent wiring issues? The ammeter / bulkhead connector issue/ circuit. The factory wiring does not have much headroom for heavier accessories CERTAINLY NOT 90AMP ALTERNATORS
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Whats the inherent issue your referring to? I'm not to familiar with bulk head problem. Thats why I'm fishing for solutions to run a separate set of supply circuits for the add on fans etc , similar to Dano's idea above . Separate from running it through the factory box .
 
Start by reading this article. The fact is an alternator more than perhaps 70A is almost guaranteed to damage factory wiring............

Some don't like the way this mod is done, and I can understand that. But the article explains why "it" is a problem. If you do nothing else, pull the bulkhead connector apart and repair/ replace the bad terminals and consider bypassing the ammeter. Also examine the ammeter for damage in any case. Then run a BIG *** wire (with fuse) from alternator to battery

The article
Catalog

Simplified diagram on that page of main power distro

The main problem is where the big red and big black ammeter wires go through the bulkhead, as well as the size of wire, and the ammeter and ammeter connections.

"Back in the day" the optional 65A alternators did a pretty much bulkhead connector bypass by modifying the harness. This is commonly known as "fleet/ police/ taxi" wiring and can be seen in some of the factory service manuals. If you are unaware you can download factory service manuals free, from MyMopar

amp-ga18.jpg
 
1969dodgedart said:
Just trolling for information and ideas on incorporating two electrical items into my car ie: stereo ( amp etc ) / electric fans ? Already have a plan just want to see what other thoughts are out there .
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I'm a believer that any additional accessory electrical load is best kept under the hood, in other words not passed through any factory connectors at the firewall.

I like to use a distribution lug or the starter relay stud and wire in any additional circuits using the correct gauge high-quality wire, Bosch relays, appropriate fuses and quality switches. I follow the Madd method basically.

I've been using Marine grade stuff the past few times I've done this type of work and find the quality much higher than what is usually available from the local parts houses.
 
67Dart273 said:
Then run a BIG *** wire (with fuse) from alternator to battery
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just out of curiosity what size wire would you call a BIG *** wire? 10 or even 8 gauge? 65’s used, I believe, 12 gauge. According to the 82 J Bodies FSM, they still used 12 gauge from the alternator - my engine compartment wiring is loosely based on a combination of J and early A wiring
 
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It depends on the alternator output and must be even larger if it's a "one wire." This is because the voltage sense for the VR is on the main (and only) charge wire. You'd have to find an appropriate recommendation, but for 90a I'd guess at least 6 and likely no4 on a "one wire"
 
67Dart273 said:
It depends on the alternator output and must be even larger if it's a "one wire." This is because the voltage sense for the VR is on the main (and only) charge wire. You'd have to find an appropriate recommendation, but for 90a I'd guess at least 6 and likely no4 on a "one wire"
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Thanks! No 1 wire alternator. Whatever size the alternator is but not more than 60 amps or so, it will have the main 12 gauge (or larger if need be), 1 field wire and the other field grounded with a known good voltage regulator that looks like a pre-69 unit
 
I'd use either no8 or a pair of no10 because they are likely easier to come up with. Voltage drop in the charge wire with a conventional "non 1 wire" is not quite as important, because the sense regulates at the battery.
 
65 Dartman said:
just out of curiosity what size wire would you call a BIG *** wire? 10 or even 8 gauge? 65’s used, I believe, 12 gauge. According to the 82 J Bodies FSM, they still used 12 gauge from the alternator - my engine compartment wiring is loosely based on a combination of J and early A wiring
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It depends on the length of the wire/cable and what the amp load is going to be. There are a multitude of charts available to help you determine the correct size you need. Just Google it. No guess work is needed. It's all been carefully researched.
 
jbc426 said:
It depends on the length of the wire/cable and what the amp load is going to be. There are a multitude of charts available to help you determine the correct size you need. Just Google it. No guess work is needed. It's all been carefully researched.
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Agreed. Ecspecialy if you have a trunck mount Battery.
 
67Dart273 said:
I'd use either no8 or a pair of no10 because they are likely easier to come up with. Voltage drop in the charge wire with a conventional "non 1 wire" is not quite as important, because the sense regulates at the battery.
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Check a stereo store for the wire. They use under 10g wire for installs.
 
jbc426 said:
It depends on the length of the wire/cable and what the amp load is going to be. There are a multitude of charts available to help you determine the correct size you need. Just Google it. No guess work is needed. It's all been carefully researched.
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Even this you must be careful of. Some charts (for automotive/ 12V) are erroneously based on AC house power charts which typically allow more voltage drop. And as I've said before IF you are using a "one wire" setup you may be well advised to step up one size even on a "good" chart. A "one wire" MUST have very little voltage drop on the charge wire. And if you are anywhere near the "step" in the chart amperage wise, you need to step up a size as well.

Tell me this: If it's been "carefully researched" then why don't ALL charts agree?
 
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