71 charger 383 ammeter bypass?

Fuel and Air Systems

  1. velrob

    velrob Well-Known Member

    Messages:
    531
    Likes Received:
    77
    Joined:
    Jan 15, 2016
    Location:
    toronto
    Local Time:
    7:36 AM
    Just curious if its a good idea to bypass the ammeter?

    Im installing a 10Gauge wire and want ability to put a new alternator down the road, 100amps.

    right now i have a 60amp stock alternator.

    i will have stock items in the car not much is changed but who knows what ill decide to add later on.

    what would be a good alternative to the ammeter? i was thinking some voltage gauge mounted under the dash.
     
  2. vance.dykes

    vance.dykes Well-Known Member

    Messages:
    357
    Likes Received:
    273
    Joined:
    Sep 22, 2017
    Location:
    florida
    Local Time:
    7:36 AM
    it would be best to a lot of the old mopar amp gauges cant handle that much amp I.M.O
     
  3. zsn0w

    zsn0w Well-Known Member

    Messages:
    82
    Likes Received:
    35
    Joined:
    Aug 2, 2018
    Location:
    Cincinnati, Ohio
    Local Time:
    7:36 AM
    I have mine set up up with two lines, one going through the ammeter and one bypassing it. In theory, if a huge drain is happening, I'll still see it on the ammeter. Otherwise, it'll read normal. It won't show slight variations now, but I'm not super concerned about that. It still looks nice and factory, and it will tell me if something is majorly wrong. No matter what you do, I'd definitely bypass the factory firewall connectors, though. Run cables through a hole in the firewall with a grommet.
     
  4. vance.dykes

    vance.dykes Well-Known Member

    Messages:
    357
    Likes Received:
    273
    Joined:
    Sep 22, 2017
    Location:
    florida
    Local Time:
    7:36 AM
    keep it for the look but it realy wont help if there is a problem. mine started to smoke from the dash so i cut and taped it . a friend of mine had his car in a trailer and when someone told him smoke was coming from the trailer when he got stopped half of the car and the trailer were burnt up bad so it is up to you but there have been problems before with the amp meter.
     
    • Agree Agree x 1
    • velrob

      velrob Well-Known Member

      Messages:
      531
      Likes Received:
      77
      Joined:
      Jan 15, 2016
      Location:
      toronto
      Local Time:
      7:36 AM
      2 lines is a good idea. but if im pulling 100amps the gauge will smoke? im not using the stock firewall bulk head. im using a newer aftermarket.
      im just worried about the ammeter catching fire
       
    • zsn0w

      zsn0w Well-Known Member

      Messages:
      82
      Likes Received:
      35
      Joined:
      Aug 2, 2018
      Location:
      Cincinnati, Ohio
      Local Time:
      7:36 AM
      From what I've read, the problem with the ammeters was generally in improper connections to the back. Make sure the terminals are clean and tightened down good and you should be alright. The only time power is going across the ammeter is when the battery is being charged or the alternator is inadequate for powering all of your accessories and the battery needs to help. If you have the two lines and they're of adequate size, you won't have to worry about it ever smoking. The line through the ammeter will have more resistance, so it will only ever really be used if there's a huge amount of current going across it - i.e. when something is wrong (shorted).
       
    • velrob

      velrob Well-Known Member

      Messages:
      531
      Likes Received:
      77
      Joined:
      Jan 15, 2016
      Location:
      toronto
      Local Time:
      7:36 AM
      Awesome thanks.

      I will run two lines.
       
    • zsn0w

      zsn0w Well-Known Member

      Messages:
      82
      Likes Received:
      35
      Joined:
      Aug 2, 2018
      Location:
      Cincinnati, Ohio
      Local Time:
      7:36 AM
      I can draw you up a diagram of how mine looks tonight when I'm done with work if you'd like. I don't claim to be an expert, but it works and is based largely on @Nacho-RT74 's setup that he's posted a lot about, and he knows a ton about the electrical systems of the 70s B Bodies.
       
    • toolmanmike

      toolmanmike Moderator Staff Member FBBO Gold Member

      Messages:
      2,196
      Likes Received:
      3493
      Joined:
      Aug 11, 2010
      Location:
      Iowa
      Local Time:
      6:36 AM
      I temporarily bypassed mine years ago. I just stacked both connectors on one ammeter pin and tightened the nut. I use one of these in the cigarette lighter. I always have my cell phone plugged in anyway.

      usb.jpg
       
      • Like Like x 2
      • RT6PK

        RT6PK Well-Known Member

        Messages:
        168
        Likes Received:
        357
        Joined:
        Aug 21, 2017
        Location:
        Poland, Ohio
        Local Time:
        7:36 AM
        I usually bypass the ammeter. Just unbolt the terminals from the gauge and bolt the two terminals together. Make sure you wrap the connection in electrical tape. Then run an aftermarket voltmeter. I have read numerous articles on this topic. The factory ammeter is the weak link in the entire system.
         
        • Agree Agree x 3
        • Disagree Disagree x 1
        • Triple Black 73

          Triple Black 73 Well-Known Member

          Messages:
          380
          Likes Received:
          165
          Joined:
          May 26, 2016
          Location:
          Atlanta, Ga
          Local Time:
          7:36 AM
          Not only good, but highly recommended! Mine caught fire in '95. We had to replace the entire engine and dash harness. And just last year I had issue were my alternator wasn't charging. I read 14v at the alternator, but only 12v at the battery and start relay. All of the volts lost at the terminal of the ammeter, and it got hot!

          You can either run the power feed to the starter relay or directly to the battery. Modern cars connect the alternator directly to the battery to reduce AC whine. If you want or need clean DC power (EFI, car audio, etc), that's the only way to do it. If keeping it stocking looking is more important than clear power, then wire it to the starter relay. The factory wired the alternator to the starter relay on cars that was order with the 100 amp upgrade alternator.

          A 10 awg cable is kinda small. The factory used a 12 awg wire. Powermaster recommends 8 awg for 105 amps. You could use a black alternator boot with a black cable if you want a more factory look. Be sure to use a 14 or 12 awg fuseable link, and ring terminal near the starter relay or battery.

          For the wiring under the dash, just connect the red to black wires with a 10-12 awg bare butt connector with heat shrink. You don't want those power lead to touch anything because they are connected directly to the battery!

          If you add a volt meter, you need one as close to the battery feed (for an accurate reading) like the ammeter joint, but key ignition so it doesn't drain the battery. You could use an usb charger outlet with a volt meter in the cigarette lighter, but you'll need to remember to take it out else you'll find a dead battery next weekend.
           
          • Agree Agree x 1
          • velrob

            velrob Well-Known Member

            Messages:
            531
            Likes Received:
            77
            Joined:
            Jan 15, 2016
            Location:
            toronto
            Local Time:
            7:36 AM
            i see alot of great posts by Nacho thx!

            I have everything apart on my car right now with dash off etc. So I can run any wire sizes. So the wire size from the ALT to the BATT should be 8AWG? to allow for the 100amp future alternator.

            I dont care about stock look but care more for clean power. I wondered why the alt went to the starter relay then to the battery.

            In this case to be safe ill bypass the ammeter and wire the alt to battery. I'd like to be able to still run the ammeter but still have clean power just to have the gauge do something but an underdash voltmeter is something i can do also.
             
            • Agree Agree x 1
            • toolmanmike

              toolmanmike Moderator Staff Member FBBO Gold Member

              Messages:
              2,196
              Likes Received:
              3493
              Joined:
              Aug 11, 2010
              Location:
              Iowa
              Local Time:
              6:36 AM
              Here's a link to the MAD ammeter bypass. http://www.madelectrical.com/electricaltech/amp-gauges.shtml
               
            • velrob

              velrob Well-Known Member

              Messages:
              531
              Likes Received:
              77
              Joined:
              Jan 15, 2016
              Location:
              toronto
              Local Time:
              7:36 AM
              funny i was just reading that right now.
               
              • Like Like x 1
              • Ranger16

                Ranger16 Well-Known Member

                Messages:
                3,291
                Likes Received:
                3910
                Joined:
                Jun 27, 2016
                Location:
                Woodstock Ill.
                Local Time:
                6:36 AM
                I was having several problems and traced it back to the ammeter. I found a bad insulator and made a new one. When I put the battery cable back on, I smoked the fusible link. Realized that there is also an internal insulator that was probably also bad. I had enough an bypassed it just like RT6PK said in post #10 and have had no problems since. I am also running a 3 gauge (oil pressure/water temp/volt meter) cluster under the dash. Between what I have read and experience, those damned things are nothing but problems. I can live with it being INOP. The volt meter serves me just fine.
                 
                • Agree Agree x 1
                • velrob

                  velrob Well-Known Member

                  Messages:
                  531
                  Likes Received:
                  77
                  Joined:
                  Jan 15, 2016
                  Location:
                  toronto
                  Local Time:
                  7:36 AM
                  What's wrong with the oil pressure and water temp gauges?
                   
                • Nacho-RT74

                  Nacho-RT74 FBBO Gold Member FBBO Gold Member

                  Messages:
                  3,136
                  Likes Received:
                  988
                  Joined:
                  Oct 8, 2012
                  Location:
                  Caracas, Venezuela
                  Local Time:
                  8:36 AM
                  if you are going to fix, you have to get deep into that, not just what you see but hidden too. When you see a damage on exterior, get inside because mostly sure inside is worst.

                  Remember we are talking about old and abussed parts. Don't pretend will work like the first day without a mantenience.
                   
                • Triple Black 73

                  Triple Black 73 Well-Known Member

                  Messages:
                  380
                  Likes Received:
                  165
                  Joined:
                  May 26, 2016
                  Location:
                  Atlanta, Ga
                  Local Time:
                  7:36 AM
                  They are basically OHMs meters with a very small 32 awg wire that can heat up and burn out. Plus, they are no where as accurate as modern volts based gauges.
                   
                  • Agree Agree x 1
                  • Triple Black 73

                    Triple Black 73 Well-Known Member

                    Messages:
                    380
                    Likes Received:
                    165
                    Joined:
                    May 26, 2016
                    Location:
                    Atlanta, Ga
                    Local Time:
                    7:36 AM
                    The factory ran the 100 amp feed wire to the starter relay because it's the shortest and easiest path (about a 4 foot run). The issue is the alternator is on the right and the battery is on the left. The factory would either had go around the radiator (which is a 7 foot run), or across the firewall and down the fender, then back to the starter relay (which would be down right crazy). They could go over the engine, if the car had a small block, but a big block has the plug wire on the front which would cause all sort of issues if the feed wire was ran near them.

                    The ammeter measures the different of amps from the battery and what the alternator puts out. In my setup, I'm already at 90 amps with everything going and I plan to install three more fans (oil, p/s, and a pusher), along with a big car-audio system. If I had an working ammeter, that sucker would be pegged deep into the C zone and never move. So, it's 100% useless. In fact, the battery doesn't have enough juice for my car to run for more than a few seconds, a minute tops. It has just enough juice to spin the motor over before the alternator kicks in (it doesn't start working until it spins 1500 rpm which is why the pulley is so small). I monitor volts via the Sniper display screen.

                    I wasn't going to show my setup or talk about it much, because I think it's could be considered bragging, but I think it's relevant since you want to wire to the battery. On the right side, you'll notice the 4 awg cable ran off the alternator (it's cover in black Tech-Flex) going through the core support and a large service loop on the left of the car. The wire is tucked neatly under the core support. There is also a 4 awg ground for the alternator going directly to the frame. This is to insure a good ground for alternator, again to reduce AC whine. There's a new 4 awg cable to the starter, and 3x 10 awg running to the fuse/relay box inside the left front fender. The 8 awg to the starter relay is a little harder to see, but it's in there and ran off the battery in the bundle of smaller wires and then into the harness near the bottom of the battery. The two 4 awg ground cable is ran to the shut off, with a 4 awg to the engine and one to the frame. The ground bolts are carriage bolts, with two nuts. The alternator is the 220 amp PowerMaster with a March Performance 3-7/8 turn buckle reduced to 3-3/8. The end result of all this is a steady 14.1 to 14.3 volts with absolutely zero whine coming from the speakers.

                    20190725_190531.jpg

                    Close up of the ground bolt. I have one on either side. The factory left a square hole on either side which I was able to fish a nickle plated steel carriage bolt through. Copper would have been better but my calculations showed this setup is good enough to meet my needs.

                    20190105_123034.jpg
                     
                  • rrTor-Red

                    rrTor-Red FBBO Gold Member FBBO Gold Member

                    Messages:
                    1,939
                    Likes Received:
                    655
                    Joined:
                    Sep 1, 2010
                    Location:
                    USA
                    Local Time:
                    6:36 AM
                    Did mine

                    Inkedthumbnail_20170225_192243_resized_LI.jpg
                     
                  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.