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  • Lights work but

    Driving with the head lights on I found that the amp meter shows about15 amps discharge, with the lights off it shows about 15 amps charge. Tail lights show about 5 amp discharge.
    After about 5 to 10 minutes driving with the head lights on the engine begins to lose power, turn the lights off and the engine runs normal again.
    I am running 50/32CP lamps in the head lights.
    I have verified there is no resistance in the wires to the head lights and have good grounds.
    Could my generator need some help?
    28 Tudor
    57 Tbird
    2kMR2 Spyder
    62 Willys Pickup

    Wise man once told me you don’t know what you don’t know

  • #2
    Headlights on and engine at fast idle, what is the voltage at the starter switch?

    Comment


    • H. L. Chauvin
      H. L. Chauvin commented
      Editing a comment
      "Could my generator need some help?"

      We all have utmost confidence in Mr. Tom W. when generator output problems are mentioned ..... especially thirty (30) amps total difference between when lights are ON or OFF.

    • CSPIDY
      CSPIDY commented
      Editing a comment
      I do not doubt his expertise, sorry I haven't replied back yet have been busy with work and play. Can check this at the two wires at the block on the firewall?

    • CSPIDY
      CSPIDY commented
      Editing a comment
      Looking at wiring diagram looks like the red wire from the ignition switch goes to the coil, is this where I should take my voltage reading?

  • #3
    Ok, with your last statement, something is off. Need pictures of how your wiring is done.
    "We do not stop playing because we grow old;
    We grow old because we stop playing ...
    NEVER Be The First To Get Old!" Pilfered from the MAFC SA Newsletter

    I JUST CAN'T FIX STUPID!!

    Comment


    • CSPIDY
      CSPIDY commented
      Editing a comment
      At work today going from memory that is not always dependable. will look at it when I get home this afternoon.

    • CSPIDY
      CSPIDY commented
      Editing a comment
      Looking at wiring diagram looks like the red wire from the ignition switch goes to the coil, is this where I should take my voltage reading?

  • #4
    Originally posted by Tom Wesenberg View Post
    Headlights on and engine at fast idle, what is the voltage at the starter switch?
    I had approx 7 VDC at either post of the coil, lights on or off. And a correction to original post with the tail light on it shows 10 amp charge.
    had to use an analog swing arm meter the digital meter was all over the place. Is this normal?
    28 Tudor
    57 Tbird
    2kMR2 Spyder
    62 Willys Pickup

    Wise man once told me you don’t know what you don’t know

    Comment


    • #5
      Originally posted by CSPIDY View Post
      Is this normal?
      Yes the Model A secondary ignition with bare wires can play havoc on some digital multi-meters. I'm able to use my more expensive digital fluke meter, it has a smooth button
      1~1931 Tudor ~ Dad
      2~1930 Tudor's ~ Lucy & Paul


      Henry Ford said
      "It's all nuts and bolts"


      Mitch's Auto Service ctr

      Comment


      • #6
        No need to go to the battery most of the time to get battery voltage. Just read the voltage at the starter switch, as the heavy cable should show no voltage drop.
        I'd like to know the voltage at the starter switch with the engine running at 1200 RPM and lights on, then again with lights off. 1200 RPM is just your best guess at speed, or call it fast idle.

        I only use my analog volt meter around cars.

        Comment


        • CSPIDY
          CSPIDY commented
          Editing a comment
          I will check this tomorrow afternoon and get back to you

      • #7
        Originally posted by Mitch View Post

        Yes the Model A secondary ignition with bare wires can play havoc on some digital multi-meters. I'm able to use my more expensive digital fluke meter, it has a smooth button
        What model Fluke meter do you use? I do have a model 75, will give it a try.
        28 Tudor
        57 Tbird
        2kMR2 Spyder
        62 Willys Pickup

        Wise man once told me you don’t know what you don’t know

        Comment


        • Mitch
          Mitch commented
          Editing a comment
          It’s at the shop so I don’t have the Model # in front of me. It has a smooth feature which allows me to use it on the A

        • CSPIDY
          CSPIDY commented
          Editing a comment
          it takes about 5 to 10 minutes for the car to start running rough, the analog meter I am using doesn't have much resolution, there has to be some difference between lights on and off. a digital meter would show that. hopefully my Fluke 75 will work.

        • Mitch
          Mitch commented
          Editing a comment
          For the record mine is a Fluke 88.

      • #8
        I always lean more towards the analog meter; but ............ positive Model A attitude and continuing to try is always commendable.

        Agree 100% ........ if it won't run right ....Fluke It !

        Comment


        • #9
          Originally posted by Tom Wesenberg View Post
          No need to go to the battery most of the time to get battery voltage. Just read the voltage at the starter switch, as the heavy cable should show no voltage drop.
          I'd like to know the voltage at the starter switch with the engine running at 1200 RPM and lights on, then again with lights off. 1200 RPM is just your best guess at speed, or call it fast idle.

          I only use my analog volt meter around cars.
          Well the Fluke 75 was no better, used the analog meter and had approx 7.5 vdc with the lights on and 8.5 with lights off when checking at the starter switch. I let run a while with the lights on. This seams a bit high don’t you think? The meter I used has been certified to be accurate. Engine was at a very fast idle.
          28 Tudor
          57 Tbird
          2kMR2 Spyder
          62 Willys Pickup

          Wise man once told me you don’t know what you don’t know

          Comment


          • #10
            Yes, that is very high voltage for charging a 6 volt battery. Ideal voltage would be around 7.2, if you had a voltage regulator. A weak battery will have less resistance and will make the generator output show higher voltage. If your battery is good, then put a 6 volt battery charger on it for several hours to be sure it's fully charged, then take the voltage readings again. I like a battery charger of 4, 5, or 6 amps. My Sears 6 amp 6/12 volt is my favorite.

            Comment


            • CSPIDY
              CSPIDY commented
              Editing a comment
              Battery is very strong, will take it for a drive and recheck tomorrow. Will charge it first.
              Last edited by CSPIDY; 09-30-2018, 09:30 PM.

          • #11
            Tom
            So after charging the battery took it on a spirited drive, afterwords rechecked the voltage at the “starter switch” and had approx 7.5 and 8 VDC lights on and lights off. I will be getting another volt meter with a better resolution to verify the voltage.
            Dave
            28 Tudor
            57 Tbird
            2kMR2 Spyder
            62 Willys Pickup

            Wise man once told me you don’t know what you don’t know

            Comment


            • #12
              Hi Dave,

              1. Sounds to me like a typical case where the third generator brush was pushed down too far to try to compensate for an "incorrect" and "yet unknown" type of extra heavy electrical draw when lights are "ON".

              2. In simple laymen terms, with lights ON and engine begins to die after 5-10 minutes this condition indicates your electrical ignition system is beginning to starve ......... then when lights are turned OFF, generator immediately charges and feeds this starving electrical ignition system.

              3. Would be great if, after trying, you would have a close-by Model A club to call for someone to further test and further observe what is going on.

              Comment


              • H. L. Chauvin
                H. L. Chauvin commented
                Editing a comment
                This may sound most parochial, but:

                A. It is ..... "known" ..... that the spark at the tips of the spark plugs become weak after 10 minutes of lights "ON" when engine is running and generator is ..... "Charging".

                B. What is ..... "un-known" ..... is ..... "the number of minutes" ..... required for the spark at the tips of the spark plugs to become weak ..... "with lights ON" ....... when engine is NOT running and generator is ..... "NOT Charging".

                Hmmmmmmmm !

              • CSPIDY
                CSPIDY commented
                Editing a comment
                I do have access to some local Model A experts, very good advise. As my quote says.

            • #13
              May have found the additional resistance in my electrical system. The car has had a habit of not starting a few times. I replaced the points and condenser and it seemed to be fixed. But yesterday it would not start again. I pulled the key switch and found It has very high resistance and sometimes an open. I have a new switch and will be replacing it this week. Will advise.
              Dave
              Last edited by CSPIDY; 10-07-2018, 09:44 PM.
              28 Tudor
              57 Tbird
              2kMR2 Spyder
              62 Willys Pickup

              Wise man once told me you don’t know what you don’t know

              Comment


              • Mitch
                Mitch commented
                Editing a comment
                Those can drive ya nuts with an intermittent
                These are the best available and be sure to insulate the back as stated in this thread further down

                https://www.vintagefordforum.com/for...on-switch-info

              • H. L. Chauvin
                H. L. Chauvin commented
                Editing a comment
                A typical Model A Forum scenario:

                a) A very humble Model A owner/student asks a question.
                b) Several Model A owner/Instructors kindly offer all sorts of different answers.
                c) The Model A owner/student tries all assumed recommended fixes for the problem.
                d) The Model A owner/student returns to report what exactly fixed the problem, whether first recommended or not.
                e) The Model A owner/student is now the "Model A Instructor" .... after telling all "Model A Students" exactly what worked.
                f) Every Model A owner/student who asks a question and reports the solution is really a great Model A "Instructor".

                Dave,

                Your initial Model A question is very much appreciated ....... we most humble Model A "students" will be glad to hear from your above reply #13 statement ...... "I have a new switch and will be replacing it this week. Will advise."

                Thanks!

            • #14
              Originally posted by CSPIDY View Post
              May have found the additional resistance in my electrical system. The car has had a habit of not starting a few times. I replaced the points and condenser and it seemed to be fixed. But yesterday it would not start again. I pulled the key switch and found It has very high resistance and sometimes an open. I have a new switch and will be replacing it this week. Will advise.
              Dave
              My experiance with troubleshooting there is never one path, only many. Sometimes you must try each path till you prove it wrong. This may not fix my light issue but it is a likely solution. That is the fun part.
              28 Tudor
              57 Tbird
              2kMR2 Spyder
              62 Willys Pickup

              Wise man once told me you don’t know what you don’t know

              Comment


              • H. L. Chauvin
                H. L. Chauvin commented
                Editing a comment
                Appears a Model A is sometimes a lot like a wife ....... a husband tries .... but never knows what path to take ..... agreeable likely solutions are also the fun part.

              • CSPIDY
                CSPIDY commented
                Editing a comment
                and I have the bruises to prove it

            • #15
              Well, finally got around to replacing the ignition switch with a new Briggs & Stratton switch, looks identical to the old one except the contact resistance is nil. With the lights on the amp meter is showing about 5 amp discharge and +15 amps with lights off. Is this normal? If not better.
              28 Tudor
              57 Tbird
              2kMR2 Spyder
              62 Willys Pickup

              Wise man once told me you don’t know what you don’t know

              Comment


              • #16
                It's normal if you have headlamps that draw 20 amps, which is a lot.
                My stock headlamps and taillight draw about 8 amps.

                Comment

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