Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Mr1964cj5

  1. #1
    Junior Member
    Join Date
    Jun 2017
    Posts
    25

    Mr1964cj5

    Can anyone help me out with a problem I have with my amp light staying on all the time. Had the generator overhauled along with a new voltage regulator. My amp light has a wire going to the ignition switch and one going to the voltage regulator. Any ideas out there?

  2. #2
    Super Moderator gmwillys's Avatar
    Join Date
    Aug 2017
    Location
    Alabama
    Posts
    2,487
    One question, is the amp light staying on all the time, even with key off? If they amp light is wired into the hot side of the key switch. I don't have a schematic handy, but it is a basic set up. If the light stays on after the key is on, and the engine is running, check for a dirty or loose ground. Hope this helps a little.

  3. #3
    Junior Member
    Join Date
    Jun 2017
    Posts
    25
    The light is only on when running. Not sure what the 2 wires hooked to the idiot light do as one goes to regulater and other to ignition switch. Only ground wire I see is the ground wire from regulater to starter case

  4. #4
    Super Moderator gmwillys's Avatar
    Join Date
    Aug 2017
    Location
    Alabama
    Posts
    2,487
    Just want to make sure. I get myself into trouble making assumptions. Most time, the regulator grounds to one of the bottom mount bolts to the fender. After painting, it's tough to grind a ground in the fresh paint. If all checks out with the ground, then the regulator needs to be checked for battery voltage when the engine is off. You installed a new regulator, and a rebuilt generator, but was the polarity set after installation? I can not link a post to help, but it can be found on the net. Also full feild the generator to make it out the max voltage.
    Last edited by gmwillys; 07-04-2018 at 07:53 PM.

  5. #5
    Junior Member
    Join Date
    Jun 2017
    Posts
    25
    I will check the ground again. Not sure what you mean full field the generator but I did do the polarity with the regulator. Not sure where to go from here

  6. #6
    Super Moderator LarrBeard's Avatar
    Join Date
    Nov 2014
    Location
    Ft. Wayne, IN
    Posts
    1,691
    Full fielding a generator is a term used to describe the process where you drive a bunch of current into the field coil to see just how much voltage the generator will produce. The voltage output of a generator is regulated by limiting the current going into the field coil.

    There are a lot of ways to do this, but here is a way that is pretty safe and won't damage anything.

    Go get a big square six-volt lantern battery - the kind with spring contacts.

    You will need a couple of jumper leads to connect it to the generator. You are going to use this battery to provide current to the generator field coil to create a magnetic field in the generator. The lantern battery won't deliver enough current to damage anything. Connect the NEGATIVE terminal to the generator ground terminal.

    Disconnect the field and armature leads from the generator. The ARMATURE is generally the larger of the two insulated terminals, the FIELD is the smaller. GROUND or NEGATIVE is the screw into the generator frame.

    Connect a voltmeter to the armature terminal of the generator. If it's a manual voltmeter, set to read about 50-volts (you can adjust later). Start the vehicle (generator is turning). Connect the POSITIVE terminal of the battery to the generator's FIELD terminal.

    You should get a significant voltage reading on the voltmeter. Vary engine speed and the voltage should vary - higher speed, higher voltage. Don't be surprised at 35 or more volts on a 12-volt system - that's why you disconnected the ARMATURE terminal on the generator; 35-volts doesn't do batteries or bulbs any good.

    If you get the high voltage from the generator, you have pretty well proven that the generator is working.

    I don't like to full field a generator using the vehicle battery because it can deliver LOTS of amps into the field coil. The lantern battery will current limit itself below damage level.

    Don't run at the high voltage too long, just satisfy yourself that things work. It is not out of the question that the "new" voltage regulator is defective. We had a new regulator fail when we were doing the '48 (another oh-by-the-way) and we used this process to isolate whether the 70-year old generator or new regulator was the problem.

    If the generator checks OK - I'd replace the regulator after I checked all of the wiring.

    Let us know what you find.
    Attached Images Attached Images

  7. #7
    Junior Member
    Join Date
    Jun 2017
    Posts
    25
    If you connect one lead of the volt meter to the armature then where do you connect the other lead?

  8. #8
    Super Moderator LarrBeard's Avatar
    Join Date
    Nov 2014
    Location
    Ft. Wayne, IN
    Posts
    1,691
    Sorry, my error in not giving complete instructions.

    Positive voltmeter lead to ARMATURE, negative to vehicle ground - make sure you have a clean place, no paint or rust.

    Let us know what you find....

    (Then, you'll be an expert).

  9. #9
    Junior Member
    Join Date
    Jun 2017
    Posts
    25
    Only other question is do I use 6 volt battery or 12 volt like the Jeep is

  10. #10
    Super Moderator LarrBeard's Avatar
    Join Date
    Nov 2014
    Location
    Ft. Wayne, IN
    Posts
    1,691
    The square lantern battery is a 6-volt battery. All it is doing is putting a couple of amps of current through the field coils. 6-volt battery is fine.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •