'fleet/taxi' wiring bypass diagram.
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67Dart273
Well-Known Member
What year / model? It is somewhat documented in some years of the service manual. "The big change" in wiring diagrams was 73, and they are VERY hard to follow "line for line"
You can download most years over at MyMopar. Some of them over there..........came from the guys here at FABO
http://www.mymopar.com/index.php?pid=31
Page 8-167 of the 72 manual shows it. That is for B body, the A is similar The original R and B ammeter wires are cut and taped off
You can download most years over at MyMopar. Some of them over there..........came from the guys here at FABO
http://www.mymopar.com/index.php?pid=31
Page 8-167 of the 72 manual shows it. That is for B body, the A is similar The original R and B ammeter wires are cut and taped off
Big thanks for this reference, seems not a lot harder than the madelectrical fix, IMO. Now a couple of questions regarding the diagram:
- Calls out 6ga wire from alt through a terminal to the bulkhead; can it be 8ga?
- Calls out a terminal block which splits out the alt lead to a fusible link/10ga wire to
bulkhead connector and continuation of 6ga wire to ammeter
are the connections at the terminal block 3 ring terminals on a single post? (sorry for the bifurcated post, fat fingered it!)
- Calls out 16ga wire from starter relay to ammeter red post, while 6ga from the
alt, I'm assuming that's to ensure as little loss from alt as possible, hence the
HD nomenclature?
Thanks for any clarification you can provide. Cheers!
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67Dart273
Well-Known Member
I'd say depends on the alternator amperage rating. If you are running a so called "one wire" DO NOT undersize or skimp on wire size, because the sensing for the regulator is on that wire, meaning, voltage drop from the alternator to the rest of the system will affect sensing, as it is "keeping the alternator happy."
67Dart273
Well-Known Member
Don't know what you are looking at. Ring terminals may be at the starter relay stud?
16ga MAY be fuse link?
Here's what I see on page 8-167. Based on this diagram a 6ga wire on the alt goes to a "terminal block" where it Ys off to:
1) direct 6ga wire to ammeter;
2) to a 16ga fuse link/10ga wire to bulkhead connector then a 12ga wire in the cabin.
Is that terminal block called out just a post terminal with those 3 wires on ring connectors bolted on to it or a 3 lugged bus?
The red wire from the starter relay to ammeter is labeled A1A-16R. The last 3 characters 16R indicate a 16ga red wire or am I reading that wrong.
Your first answer was one part of the puzzle: yes I need a 6ga wire. Thanks for the prompt reply, really helps.
I'm not sure why you'd want to go through the hassle of that deal. Looks like more trouble than it's worth and cutting up a harness with other solutions out there.
I already have the harness apart from putting new bulkhead connectors (cleaned them all and replaced a few terminals in them as well) on both sides of the firewall. For grins I figured I'd look up what the 65 amp alt (AKA taxi) wiring required before I closed up. It appears (still not sure I'll do it) that it wouldn't require much extra on my part to make this change.
I'm not sure where cutting up the harness is required. The diagram shows where the only bulkhead wire (A1) in this set up runs on both sides of the firewall on the specific '72 connector. It enters and exits the firewall at connector slot 18. On my '67 that would be connector slot P.
My bigger (not clearly stated) concerns are:
1) The gauge changes for the A1 wire (fusible link notwithstanding)
2) The 16ga size of A1A wire (starter relay to red terminal on the ammeter)
3) The terminal block where the 6ga R6C wire from the alt splits to A1 and R6B. I've
found a p/n 1842267 which I think is the terminal block for the L/N 65 amp alt (not
sure if a must have)
And, as was explained earlier, the 6ga black wire from the alt to ammeter is that size for very good reason.
OK,
Says cut and tape on the schematic.
The 6ga wire to the ammeter stud is a blessing and a curse. Great for capacity! If the ammeter ever shorts out, you have a HUGE wire feeding that dead short with NOTHING to stop it. If you have huge amp draws inside the car, and it's fairly clear that OEM wiring doesn't matter, run a dedicated circuit to feed those loads. Using what the factory did back then seems a little old school when there are better more current approaches available.
I see you wonder why a 6ga feeding the ammeter and a 16ga from ammeter to starter relay. Think about the possible repercussions from that. None of them are good!
This upgrade is not all it's cracked up to be, it's the factory attempting a band aid fix too the horrible charging system design. There are bad things that can happen, especially with the factory ammeter in place. Many disagree with that viewpoint, yet I've never seen a disconnected ammeter ever catch on fire!
The Mad approach, even though not my preferred method, is better than the fleet one.
I won't rain on the parade from here on out.
Says cut and tape on the schematic.
The 6ga wire to the ammeter stud is a blessing and a curse. Great for capacity! If the ammeter ever shorts out, you have a HUGE wire feeding that dead short with NOTHING to stop it. If you have huge amp draws inside the car, and it's fairly clear that OEM wiring doesn't matter, run a dedicated circuit to feed those loads. Using what the factory did back then seems a little old school when there are better more current approaches available.
I see you wonder why a 6ga feeding the ammeter and a 16ga from ammeter to starter relay. Think about the possible repercussions from that. None of them are good!
This upgrade is not all it's cracked up to be, it's the factory attempting a band aid fix too the horrible charging system design. There are bad things that can happen, especially with the factory ammeter in place. Many disagree with that viewpoint, yet I've never seen a disconnected ammeter ever catch on fire!
The Mad approach, even though not my preferred method, is better than the fleet one.
I won't rain on the parade from here on out.
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Fair enough. A matter of curiousity as to what was done by the factory.
Several differences mean that its not appropriate to directly translate that 65amp alt '72 Satellite wiring to a '67 Barracuda, Dart or Valiant. It appears we are looking at an option group that includes an perhaps an optional electric fuel pump and other electric powered accessories. That said, I'll give it a shot.
1) The gauge changes for the A1 wire (fusible link notwithstanding)
A1-10 R carries the current to the main splice (distribution point) for all the normal systems. 10 gage was considered plenty for power demands of a fully optioned B-body.
Presumably its 10 gage on both sides of the bulkhead connector.
R6C-6 BK may be larger to minimize losses oever the distance, especially in the hot engine compartment. In addition to the power needs tied to the main splice, at times it will have to recharge the battery. Therefore a larger size makes sense.
2) The 16ga size of A1A wire (starter relay to red terminal on the ammeter)
In a normal use, the wire only carries current to recharge the battery. As long as the battery is not run down, its not alot of current. That's the thinking anyway...
When starting, power will go through the other way, but again, its not a lot. It will be the amount needed by the ignition and the starter relay - maybe 5 amps.
Protection has been moved to the battery side of the starter relay. It doesn't say what size that fusible link was, but since the relay draws a fair amount of power, it wouldn't surpise me if it was 2 sizes smaller than the 10 gage, rather than the 16 gage. My guess is that the 16 gage line to the ammeter also had a fusible link even this diagram doesn't show it.
3) The terminal block where the 6ga R6C wire from the alt splits to A1 and R6B. I've found a p/n 1842267 which I think is the terminal block for the L/N 65 amp alt (not sure if a must have).
I'm with Rob, I don't see the reason for replicating this system, unless you are recreating a '72 taxi or ? with the same options. It's interesting to study to better understand the strategy and borrow ideas as appropriate.
In dark red is the power flow when the engine is running and the battery is charging (dashed lines) with the setup as shown.
My guess is the terminal block represents a further modification of the bulkhead bypass (wires through grommet).
The next diagram shows the powerflow if the wires were not cut and no power went through the bulkhead connector. However if the bulkhead connection was there, along with the bypass, it would work pretty much same except the power would divide along the paths the paths of least resistance. Without knowing where the A1 line from the ammeter goes, its impossible to guess whether there is current in it....
edit: Perhaps the dashed A1-12R was a way to partially bypass the ammeter during start up? or engine off? Maybe for an electric fuel pump, or two way radio?
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If you really like the idea of reducing losses and resistance points like the factory did, you can implement that by running new wires through a grommet, and optionally keep the ones through the bulkhead. Attach them by splicing or with ring terminals on the back of the ammeter. On the starter relay, its probably still best to have just one fusible link and then split.
Conceptually it looks something like this if the original wires through the bullkhead are retained.
Conceptually it looks something like this if the original wires through the bullkhead are retained.
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These drawings can be a little confusing. The dashed lines indicate the "normal" wiring paths. The "cut and tape" indicates there isn't a big loop through both the ammeter and big splice. The normal loop also has everything going through the bulkhead connector.
In the 65 amp alt configuration R6B and A1A go through a separate grommeted firewall hole, terminate at the ammeter and do not pass go or go through the infamous "big splice". The big splice gets power from the A1 wire though the bulkhead and is somewhat isolated. The At least that's how I'm deciphering it and how I've read it described by many others. 'Til I saw this diagram it didn't make sense.
As far as the comments, they're ALL helpful. Heck, just got Rob's madelectrical bypass cable this week. Yeah, I'm covering all my bets. Just got my new repop cabin-side bulkhead connector, so its in my near future. Cheers!
Yes we agree. That's what my diagram shows.
My second diagram is a speculatation on why the 6 gage wire extends from the terminal block.
What I am suggesting is that this particular wiring is a modification of some other fleet wiring that did not cut the wires. My guess is that its the remnant of another setup, but not the standard one. This is why the 6 gage wire continues to the ammeter stud; from there some of the power went to battery, maybe some to the mystery A1-12R, and most to the main junction.
I'm basing this on the presumption that a regular '72 Satelite
a) has alternator power going to the bulkhead connector, and
b) does not have any extra wires on the battery side of the ammeter.
So its just a guess.
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