pulsating headlights at idle / 66 valiant

[pigman]

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 ****, 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:

 

[cuda67]

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.

 

[toolmanmike]

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

 

[67Dart273]

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

 

[kt340sport]

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!!!!!!!!!!!!!!