pulsating headlights at idle / 66 valiant

Electrical and Ignition

  1. pigman

    pigman Member

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    HEY guys,
    Just finished installing a new heater core, 1st time out at night and at idle, she pulsates thru the headlights/ lights brighten then dim/...kick up the throttle, same shit, but turn a signal switch on and it stops...makes me think maybe a voltage regulator, the later is possibly an alternator needs changing, what do you think..?????
    1966 Plymouth valiant signet / SLANT 6 :help:
     
  2. cuda67

    cuda67 Well-Known Member

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    Mine did the same thing, not serious, but annoying. I replaced my voltage regulator and all was fine. I did replace the alternator later on but that was weak.
     
  3. toolmanmike

    toolmanmike FABO Staff Staff Member FABO Gold Member

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    Regulator, but make sure all the connectors and grounds are clean. (especially all the bulkhead connectors)
     
  4. 67Dart273

    67Dart273 Well-Known Member

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    This certainly CAN be the regulator but it also can be other causes.

    If you still have the old electro--mechanicaly relay regulator, buy an new one, and most replacements are actually "solid state." To easily tell the difference......look at the bottom

    The old style regulator has two big wirewound resistors underneath

    The modern replacement has none

    I am NOT referring to the 70/ later electronic regulator which MUST use an isolated field (incorrectly called "dual field") alternator

    IF you replace the alternator for any reason DO ask for and buy the later so called "squareback' mid-70's isolated field alternator. Even if you don't convert to the 70/ later regulator, you can ground either field terminal and use your replacement regulator. The squareback design gives better low speed output. Do NOT accept the old style.

    This link is the old style mechanical regulator with two resistors:

    http://vintagemoparts.com/img/p/440-1620-thickbox.jpg

    The link below is a solid state replacement for the above, most likely what you'll get

    http://i10.ebayimg.com/02/i/001/2a/fe/80f4_35.JPG

    This link is a more expensive replacement regulator

    http://ecx.images-amazon.com/images/I/41-aG0961CL._SL500_SS500_.jpg

    Left below is the better "squareback" design

    [​IMG]
     
  5. kt340sport

    kt340sport Well-Known Member

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    Great information here from 67dart273, anybody with electrical issues he knows what he is talking about .Great to know .Wish i new more electrical hate it with a passion!!!!!!!!!!!!!!
     
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