is this safe?
bypass video
- Thread starter sabre67
- Start date
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leaving the original wiring as is
Our Member @crackedback has a really nice kit for this. It includes good quality wire, a fusible link (for safety)and is custom built to fit. Great customer service, at a reasonable price. Look it up.
67Dart273
Well-Known Member
1...That new wire really should be fused/ breakered/ fuse linked
2...You should not leave the factory wiring "as is" in the strict sense. You should pull the bulkhead connector apart, inspect ALL the terminals and repair or replace them. The red/ black former ammeter wires are now in parallel to feed power into the interior, and even though they now share that load, and no longer have to carry the alternator current, they DO need to carry current and still operate. "Voltage drop."
3...You should consider bypassing the ammeter by bolting the red and black together in at the ammeter, in case the ammeter itself is compromised, which happens
4...You should inspect and repair ALL bulkhead connector terminals, AND check for voltage drop most especially in the ignition "run" line, which can at the very least cause over charging (over voltage) problems
2...You should not leave the factory wiring "as is" in the strict sense. You should pull the bulkhead connector apart, inspect ALL the terminals and repair or replace them. The red/ black former ammeter wires are now in parallel to feed power into the interior, and even though they now share that load, and no longer have to carry the alternator current, they DO need to carry current and still operate. "Voltage drop."
3...You should consider bypassing the ammeter by bolting the red and black together in at the ammeter, in case the ammeter itself is compromised, which happens
4...You should inspect and repair ALL bulkhead connector terminals, AND check for voltage drop most especially in the ignition "run" line, which can at the very least cause over charging (over voltage) problems
Snake
Mopar Nut
well said
if i went that route. how large of a fuse should be used in that added wire?
67Dart273
Well-Known Member
Depends on wire size and alternator output. This is a BIG problem with the original design. Even with say, 40-45A alternators, the fuse link is really too large for the harness, but must be large enough not to blow in normal operation.
I would tend to use an OVER size wire and an UNDER size fuse, again depending on alternator and wire size.
And if you are using a "one wire" you MUST oversize the charge wire because the "sensing" is done with that wire. ANY voltage drop on that wire (because of large alternator/ small wire) will cause voltage sag at the battery and loads
I would tend to use an OVER size wire and an UNDER size fuse, again depending on alternator and wire size.
And if you are using a "one wire" you MUST oversize the charge wire because the "sensing" is done with that wire. ANY voltage drop on that wire (because of large alternator/ small wire) will cause voltage sag at the battery and loads
ok thanks for your input,much appreciated
The guy in that video should be more concerned with the battery positive lug and the wires going into it. That is some rough wiring. 
There is some info in that video that is not exactly correct.
If you want to run a cable from alternator to battery, make sure it has protection in it.
There is some info in that video that is not exactly correct.
If you want to run a cable from alternator to battery, make sure it has protection in it.
if i use 6ga wire would a 30 amp fuse work? my alternator is stock 318 swinger
Your alternator has probably been changed a couple times in the last 50 years. Original alternators were 34 to 56 amps. A lot of the ones you get today are 60 to 100 amps and now run it through 50 year old wires and connectors that have never been cleaned (see above).
I am a big fan of ammeters. They tell you a lot about what is going on electrically in your car. A volt meter is like an oil pressure idiot light - it tells you that you are screwed after you're already screwed. You can see things failing on an ammeter that will never show up on a voltmeter. The original ammeters were never meant to last 50 years (5 years or 50,000 miles whichever comes first, right?). My favorite way to avoid disaster is:
1) replace the original wiring with an in kind replacement (M&H is my source) underhood and dash
2) if you find the need to install a bunch of add on stuff that uses electrical power, do what Chrysler did for cab and cop cars - replace the 2 main wires in the bulkhead connectors with larger gauge wires and drill and grommet holes for them eliminating the bulkhead connection for these to wires. Run new fused wires for the new stuff (don't add their load to original well designed circuits).
3) leave the original ammeter in the dash for looks (not hooked up) and install an aftermarket ammeter under the dash along with a voltmeter (and while you are at it a mechanical oil pressure gauge)
Now you have a much better idea of what is going on under your hood while driving, and don't have to worry about a catastrophic fire for another 50 years. Yeah, I know this ain't cheap, now add up the cost of everything you have done to get your car and everything you've spent on it since and think about it all burning up on the side of the road...
I am a big fan of ammeters. They tell you a lot about what is going on electrically in your car. A volt meter is like an oil pressure idiot light - it tells you that you are screwed after you're already screwed. You can see things failing on an ammeter that will never show up on a voltmeter. The original ammeters were never meant to last 50 years (5 years or 50,000 miles whichever comes first, right?). My favorite way to avoid disaster is:
1) replace the original wiring with an in kind replacement (M&H is my source) underhood and dash
2) if you find the need to install a bunch of add on stuff that uses electrical power, do what Chrysler did for cab and cop cars - replace the 2 main wires in the bulkhead connectors with larger gauge wires and drill and grommet holes for them eliminating the bulkhead connection for these to wires. Run new fused wires for the new stuff (don't add their load to original well designed circuits).
3) leave the original ammeter in the dash for looks (not hooked up) and install an aftermarket ammeter under the dash along with a voltmeter (and while you are at it a mechanical oil pressure gauge)
Now you have a much better idea of what is going on under your hood while driving, and don't have to worry about a catastrophic fire for another 50 years. Yeah, I know this ain't cheap, now add up the cost of everything you have done to get your car and everything you've spent on it since and think about it all burning up on the side of the road...
67Dart273
Well-Known Member
30 is rarely enough. Get into the "audio freeks" depts and look for those big fuses, one type is called a "maxi fuse."
According to this page
6ga at 4-7 ft is about 125 amps capacity. If you think your alternator is below 50 I'd use about a 50A fuse.
This chart here might be better but harder for me to read
Automotive Wire Amperage Capacity Chart - Jasco Automotive Ltd
AUTOMOTIVE Wire Amperage Capacity Chart Recommended Length and Amperage for Automotive Wire while maintaining a 2% or less voltage drop at 12 volts Automotive Wire Size 5 Amps 10 Amps 15 Amps 20 Amps 25 Amps 30 Amps 20 Gauge Wire (AWG) 4.5 ft 2.2 ft 1.6 ft . 18 Gauge Wire (AWG) 7.3 ft […]
jascoautomotive.com
thanks for your reply and input.Good advice duely noted 
67Dart273
Well-Known Member
I was going to add, and many disagree, but if you can use "lots of oversize wire size" so you have "headroom," and then undersized the fuse UNDER what the wire is rated for, but large enough to handle the maximum alternator output, this creates, essentially, a faster blowing fuse before the wire is in any danger of overheating. This is in fact the OPPOSITE of what Chrysler did with the relatively small wire, and relatively slo blowing fuse link.
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