BYPASS the AMMETER? (1969 A12)

Electrical & Ignition

  1. 747mopar

    747mopar FBBO Gold Member FBBO Gold Member

    Messages:
    12,351
    Likes Received:
    15279
    Joined:
    Oct 30, 2012
    Location:
    ohio
    Local Time:
    3:14 AM
    Good for you.... not sure what your point was:rolleyes:.
    I won't argue that point. For me it's a matter of preference, I like seeing the state of my battery vs amps, obviously if the volts are dropping your in trouble but at least you know where you are.
     
    • Like Like x 1
    • Agree Agree x 1
    • Don Frelier

      Don Frelier FBBO Gold Member FBBO Gold Member

      Messages:
      3,497
      Likes Received:
      3887
      Joined:
      Oct 11, 2016
      Location:
      Ionia, NY
      Local Time:
      4:14 AM
      My point was that you indicated these were reasons to switch to a voltmeter. I'm saying they are so rare or nonexistent they don't support the reasoning.
       
    • 747mopar

      747mopar FBBO Gold Member FBBO Gold Member

      Messages:
      12,351
      Likes Received:
      15279
      Joined:
      Oct 30, 2012
      Location:
      ohio
      Local Time:
      3:14 AM
      I indicated that I "personally" like Voltmeter's because you can see the state of your battery and threw in a few examples. No I don't throw belts, I have had it happen during a burn out, I've had a power steering pump lock up which smoked the belt, shit happens. It's like anything else, all preference, no wrong answer as long as things are done correctly. I've had both, both are useful tools, voltmeter's just tell me what I want to know.
       
      • Agree Agree x 1
      • Don Frelier

        Don Frelier FBBO Gold Member FBBO Gold Member

        Messages:
        3,497
        Likes Received:
        3887
        Joined:
        Oct 11, 2016
        Location:
        Ionia, NY
        Local Time:
        4:14 AM
        I have both on my charger. I find the ammeter more useful. It has electric fans and with the array of taillights the voltage will drop to 12volts at a light with the brakes on. Now if you put a voltmeter on a non running car and it read 12 volts it would need a charge. yet in this instance the battery would actually be almost fully charged I just have a high load at idle which is set pretty low around 625 rpm.
         
        • Like Like x 2
        • WM23M9

          WM23M9 FBBO Gold Member FBBO Gold Member

          Messages:
          249
          Likes Received:
          134
          Joined:
          Feb 28, 2020
          Location:
          Kansas City, MO
          Local Time:
          3:14 AM
          So, I ask Year One's guru regarding using the harness HU199BM (Elect Ign Modified). He tells me.....

          "Note that the engine harness, like the original harness, is not wired to support alternators rated higher than 55 amps. If an alternator rated above 55 amp is desired you will need to add a heavier charge wire. Also, adding the charge wire will result in current bypassing the ammeter, reducing the indicator needle movement. You may want to add a voltmeter or other device to monitor the charging system function".

          Here's the tag or sticker from alternator been in my car for 3 years... Could THIS have caused a Ammeter wire to fail?
          20200715_134849.jpg
           
        • 72RoadrunnerGTX

          72RoadrunnerGTX FBBO Gold Member FBBO Gold Member

          Messages:
          1,294
          Likes Received:
          857
          Joined:
          Jan 14, 2009
          Location:
          Shoreline, Washington
          Local Time:
          1:14 AM
          A higher output rated alternator, on its own, won’t cause wiring to overheat. Excessive current burns wires, you need a short or other over-load condition to melt wires. That said, when up-sizing the alternator, the charge circuit wiring needs to be up-sized as well to handle the potential alternator output current as determined by the current total vehicle running loads.

          The M&H reproductions are just that, copies of the original harnesses, including undersized charge circuit wires running through the bulkhead connectors, the real weakness in the design. I unwrap them, replace the 12ga charge circuit wires with 8ga marine grade wires routed around the bulkhead connector, through a firewall grommet, directly to the ammeter (as the factory did on their later fleet vehicles with larger alternators). Likewise, the charge circuit run to the starter relay in the forward lighting harness. The fusible link will need to be up-sized as well.

          End result; a factory appearing harnesses that can handle any and all modern loads I want, a fully functional ammeter, providing way more info than a simple voltmeter.
           
          • Agree Agree x 1
          • WM23M9

            WM23M9 FBBO Gold Member FBBO Gold Member

            Messages:
            249
            Likes Received:
            134
            Joined:
            Feb 28, 2020
            Location:
            Kansas City, MO
            Local Time:
            3:14 AM
            Wow, makes perfect sense now. Seems like the RED 12Ga Ammeter wire is a little "wimpy". Unable to find exactly what amperage a factory Alternator did put out, I really have no choice. Seeing lot of owners going to 90 amp alternators and 4 Ga wiring. But these same people running electric fuel pumps, fans and stereos. None of which I intend to ever use. It sucks that I guess since using Electronic Ignition now, really have no choice. As reading the diagrams shows, the black feed off the Ammeter is main source to everything else behind the firewall.. This should be fun..

            Thanks!!
             
          • 72RoadrunnerGTX

            72RoadrunnerGTX FBBO Gold Member FBBO Gold Member

            Messages:
            1,294
            Likes Received:
            857
            Joined:
            Jan 14, 2009
            Location:
            Shoreline, Washington
            Local Time:
            1:14 AM
            BTW, On the charge circuit bulkhead by-pass described, if you are not adding loads to the dash harness, it is not necessary to modify any wiring in the dash harness. Leave the black harness ammeter lead on the ammeter to feed the factory splice, disconnect and tape back the red lead.
            Amp gauger.jpg


            60amp max output alternator, A12 car, absolutely no loads other than factory stock, no A/C added, no headlight upgrades? I’d have no problem running the reproduction harness as is with one exception, by-pass the bulkhead connections on the charge circuit, both directions.
             
            • Like Like x 1
            • WM23M9

              WM23M9 FBBO Gold Member FBBO Gold Member

              Messages:
              249
              Likes Received:
              134
              Joined:
              Feb 28, 2020
              Location:
              Kansas City, MO
              Local Time:
              3:14 AM
              The RED charging wire you modified, runs directly from ALT Output I'm thinking?

              Cant seem to rely on the diagrams any longer. A12's must have been different, the colors more closely resemble .a 69 Dart!
               
            • 72RoadrunnerGTX

              72RoadrunnerGTX FBBO Gold Member FBBO Gold Member

              Messages:
              1,294
              Likes Received:
              857
              Joined:
              Jan 14, 2009
              Location:
              Shoreline, Washington
              Local Time:
              1:14 AM
              Yes, That’s a ’72 Rallye cluster. Layout is a bit different but basic charging system color coding is the same. Those are 8ga wires.

              Ok, forget that picture and comments relating to wire size upgrades for your current scenario, a bone stock electrical system replacement, no added loads. On a ’69, with new engine and dash harness, I would remove the 12ga black charge circuit wire/Packard connector from the bulkhead connector (firewall side), cut and carefully splice an extension lead, route it through the firewall to the ammeter black side stud, leave the dash harness black lead in place. I believe the ’69 has the fusible link connecting directly into the bulkhead connector on the firewall side. I’d remove its Packard connector from the bulkhead connector and splice an extension lead to it, routing to the ammeter red side stud directly, again the existing dash harness red lead can stay put. It’s the Packard connectors that create the most trouble over time.
               
              • Like Like x 1
              • 72RoadrunnerGTX

                72RoadrunnerGTX FBBO Gold Member FBBO Gold Member

                Messages:
                1,294
                Likes Received:
                857
                Joined:
                Jan 14, 2009
                Location:
                Shoreline, Washington
                Local Time:
                1:14 AM
                The red ammeter lead runs to the battery via the bulkhead connector/fusible link connected to the starter relay.

                If you are not up-sizing the entire charge circuit wire run, the extension leads can be 12 ga as well, nothing gained by short lengths of larger wire. I'd use 10 ga for the extensions, good soldered splices, shrink tubing, good quality grommet.

                Yes, your old bulkhead charge circuit connections burned up from excessive resistance and resulting heat at the Packard connectors.
                 
                Last edited: Jul 23, 2020
                • Like Like x 1
                • WM23M9

                  WM23M9 FBBO Gold Member FBBO Gold Member

                  Messages:
                  249
                  Likes Received:
                  134
                  Joined:
                  Feb 28, 2020
                  Location:
                  Kansas City, MO
                  Local Time:
                  3:14 AM
                  What IF, I use a 55 AMP single grove pulley Alternator?!!
                  Screenshot_20200724-011615_Chrome.jpg

                  No wiring work needed?
                  Just reconfiguring alternator brackets I suppose?
                   
                  Last edited: Jul 24, 2020
                • Nacho-RT74

                  Nacho-RT74 FBBO Gold Member FBBO Gold Member

                  Messages:
                  4,340
                  Likes Received:
                  1452
                  Joined:
                  Oct 8, 2012
                  Location:
                  Caracas, Venezuela
                  Local Time:
                  5:14 AM
                  Ok several notes because I still can see lot of stuff is not clear.

                  The alt just will put out whatever load the car requires as far is able to. Your car is what sucks 30, 40 or 50 amps, so the wiring must be matched to the loads it requires, NO MATTER the alt you have. The amperes are not pushed in by the alt but sucked out by car. If the alt doesn't have the capacity, the batt will be sucked out. But still will demand same load.

                  The problem with stock alts is they are really poor at iddle and low speeds, which depending in your driving or city, could be the most time spends ( traffic, rain ) so it keeps sucking from batt, then you give gas, and alt has to supply per battery demand, the load lost while alt was not capable. What I said the trick on this? If your car sucks a constant 30, 40, 50 amps loads then keep the batt out of the game sucking more amps... 30 amps becomes maybe in 45, 40 amps becomes on 53, 50 amps becomes on 64 amps... these extra 15, 13, 14 amps are the one being sucked by the batt to get recharged again then this will be the load going through the ammeter as a Charge reading.

                  While the batt is charged, the load supplied by the alt will be JUST for the car, right on the splice between ammeter and bulkhead on black wire. It won't be running anymore to batt and ammeter won't get any load going throught, zero reading. no load it means no heat. This is the ideal status.

                  The batt is just like a baby! Will be sucking milk while is hungry! When is not hungry, won't suck anymore!

                  Sure it will be load running throught the bulkhead, SPECIALLY on black wire, not so much on red wire ( same reason, batt is full, and won't be running load to that side ) so, the bulkhead bypass will save this loads. It can be done on several ways. 72RoadrunnerGTX chosen just forgett the bulkhead path and keep exclusively the bulkhead bypass. Myself I preffer to keep the bulkhead path and get an extra one being parallel. Why? Because in that way the main splice, which is in the middle between ammeter and bulkhead, will keep being sourced from both sides, the wire between splice and ammeter, and the wire between splice and bulkhead. This means the splice is being feeded by 2 12 gauge wires. Using just one path, the one bypassing the bulkhead despiting the stock one running throught the bulkhead, even if you use an 8 gauge wire, the main splice is still being feed by just 1 12 wire, the existant one between ammeter and splice. Sure you still will be safer to feed the batt when required with this, but IMHO you can keep doubled the sourced to the main splice keeping the stock one.

                  72RoadrunnerGTX is using what it was done from factory on earlier cars and later upgraded at dealers, but on laters factory setup with high load cars the bulkhead path was kept in place, adding the extra path without despite the bulkhead one. 73/74 diagrams show keep the bulkhead path still using the extra one.


                  Is true stock ammeter are designed to work. On +/-40 amp range, so it won't hold 50, 60, 90 amps, but ONCE AGAIN, the alternator will never put 90 amps, because your car will never suck 90 amps on normal conditions. The deal with 90, 130 amps is get the best iddle capacity ( 40, 50 amps ) to keep the batt out of the game, hence the ammeter too.

                  ASIDE THIS, You can't speed up the charge on batt even having a 400 amps alternator! Batteries gets it own chemical process to be recharged and you can't push it up. Once again, as a baby, it will get its own speed to suck the milk! in NORMAL conditions, a discharged batt can suck maybe 30 amps for 3 or 5 minutes, but once this initial process began, it will be into 10-20 amps untill is fully charged. The more charged, the less load will be sucking and you'll see this load through the ammeter. So you will see THIS LOAD going through the ammeter on its reading, not the full 90 or 130 amps from alt
                   
                  Last edited: Jul 24, 2020
                  • Like Like x 1
                  • Agree Agree x 1
                  • WM23M9

                    WM23M9 FBBO Gold Member FBBO Gold Member

                    Messages:
                    249
                    Likes Received:
                    134
                    Joined:
                    Feb 28, 2020
                    Location:
                    Kansas City, MO
                    Local Time:
                    3:14 AM
                    Ahhh, I see! So going BACK to a 55 amp alternator really wont help at all?
                    Wow
                    Screenshot_20200724-011615_Chrome.jpg
                     
                  • WM23M9

                    WM23M9 FBBO Gold Member FBBO Gold Member

                    Messages:
                    249
                    Likes Received:
                    134
                    Joined:
                    Feb 28, 2020
                    Location:
                    Kansas City, MO
                    Local Time:
                    3:14 AM
                    Man, what a pain in the butt!
                    LoL.. So best advice? Stick with the 60 amp I have?
                     
                  • WM23M9

                    WM23M9 FBBO Gold Member FBBO Gold Member

                    Messages:
                    249
                    Likes Received:
                    134
                    Joined:
                    Feb 28, 2020
                    Location:
                    Kansas City, MO
                    Local Time:
                    3:14 AM
                    If I could find a DIAGRAM on how someone did this, be so much easier...

                    Thank.You!!
                     
                  • Nacho-RT74

                    Nacho-RT74 FBBO Gold Member FBBO Gold Member

                    Messages:
                    4,340
                    Likes Received:
                    1452
                    Joined:
                    Oct 8, 2012
                    Location:
                    Caracas, Venezuela
                    Local Time:
                    5:14 AM
                    I was to quote this before the later reply LOL.

                    a 55 amps alt is sure an improvement over a 50 or 45 older amps, but will still feed 25/30 amps iddling as max output. At day light and no traffic is quite enough BUT As soon you are in traffic, let's say at night, press brakes, headlights on and even worst, RAINING ( wipers on ) you'll see your ammeter going down to discharge, headlights will dimmout, wipers going slower. Wipers by them self sucks around 10-12 amps! You can check that with engine off and turn them on. The ammeter will register that load coming out from the batt!

                    You don't have AC but got heater I guess. The blower is the problem with them, not th AC by itself. blower sucks also 8-15 amps depending on speed selected. Sure AC adds a problem because compressor reduces the engine speed, which also makes slow down the alt, getting less juice, but blower sucks the same on both

                    The alternator decal you posted shows 81 amps as max output and 41 at 2000 ALTERNATOR RPMs. That is maybe 35-38 amps at 750-800 RPMs engine.
                     
                    Last edited: Jul 24, 2020
                  • Nacho-RT74

                    Nacho-RT74 FBBO Gold Member FBBO Gold Member

                    Messages:
                    4,340
                    Likes Received:
                    1452
                    Joined:
                    Oct 8, 2012
                    Location:
                    Caracas, Venezuela
                    Local Time:
                    5:14 AM

                    Sure is was made... ON THE TREAD I POSTED AT DODGECHARGER.COM!!! lol.

                    Several updates made along the years, so check it all.
                     
                  • WM23M9

                    WM23M9 FBBO Gold Member FBBO Gold Member

                    Messages:
                    249
                    Likes Received:
                    134
                    Joined:
                    Feb 28, 2020
                    Location:
                    Kansas City, MO
                    Local Time:
                    3:14 AM
                    Yep. Its still on car, was putting out 15.05V at idle..
                    Thought maybe thats too much? Especially at idle!

                    Seemed to run fine with it until i got this burnt up.ECU problem. Decided to just replace all the wiring. It was fried.
                     
                  • Nacho-RT74

                    Nacho-RT74 FBBO Gold Member FBBO Gold Member

                    Messages:
                    4,340
                    Likes Received:
                    1452
                    Joined:
                    Oct 8, 2012
                    Location:
                    Caracas, Venezuela
                    Local Time:
                    5:14 AM
                    15 volts is not necesarilly a charge status! It could be a regulator deal, or even a malfunction alt. Once I had 18 volts and discharge on ammeter. Alternator was shorting while spinning ( one of the stator leads making friction with one of the rotor vent vanes wile spinning ). This caused a voltage spike, but a load lack. Still with 18 volts I unplugged batt and engine stalled.

                    Volts can burn stuff but never will melt anything. Volts doesn't cause heat! Amperes does.

                    High Volts rate can go througth a hair thick wire, amperes not.
                     
                    • Like Like x 1
                    1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
                      By continuing to use this site, you are consenting to our use of cookies.