I have this problem on my 69 b body. At idle the interior lights are not as bright. When I hit the gas they go brighter and then without removing my foot of the gas pedal the light starts to go bright then dimmer then bright again. Almost like the light is pulsating. I have drilled out the bulk head connector and ran two new wires to the amp gauge from the engine bay. Any help would be great.

have you upgraded to the electronic replacement for your voltage reg?
if you are still using the old style, that is probably the problem.

If you are still using the stock single field alt with the original style mechanical voltage reg then what you are describing isn't unusual..

There are points in the regulator that open and close to regulate the voltage. Thats what you are seeing with the lights pulsing.

They have electronic regulators that smooth out the voltage.

Yes I am using the 1 fld alternator and the blue mopar constant voltage regulator that summit sells.

You need to add relays to run the headlights

http://www.madelectrical.com/electricaltech/brighter-headlights.shtml

Some good info here too:

http://www.allpar.com/history/mopar/electrical.html

Is it worth spending the extra money and changing the alternator to a dual fld and upgrading to the 70's voltage regulator, or should I just add the VR706 regulator and keep the 1 fld?

What size alternator (amps) can you use with the factory wiring gauge?

Did all B body's use the same wire gauge regardless of your options?

We run the new solid state regs on a few cars.Night and day difference in the charging.They are cheap at about 20 bucks and look stock and no wires to cut.My 65 I run a dual field new 78 amp alt and reg.They didnt make the SS reg when I converted it.My son runs full MSD with digital 6 and big stereo.No charging problems with the OE 62 aly.Your brushes might be going if its the OE alt.Easy to change.Rocky

Make sure you have a ground strap between the motor and the body.

I'd get a later 78 amp 2 field terminal alt for iirc an ?85 M body and an OE '70 up flat v regulator and you can trim its' sides & redrill one of the holes and it will nestle neatly onto the squarish firewall recess where the "box" VR resided. Just takes 1 extra wire and the diagram is in the archives. The blue constant voltage reg (741/742 iirc) is more of a race item tho people have used it sucessfully on the street I think it is an ineffective bandaid and will over the (very) long run shorten batt life. EDIT flickering lites is a common symptom of the old mech regs so if you have a solid state one (race or OE) then what Rock said, alt (brushes)

Robert a lot of people want the OE look.My kid runs the 62 stock alt with new reg and no problems charging.Now if looks dont matter the new style is easier to get.I have a Summit chrome alt in my 65 was like 75 bucks new.4 years now and still charges great.Rocky

Okay I have replaced the blue constant voltage regulator for the autozone vr706. It made no difference. I performed some test and these are my results.


Start the engine and turned on the headlights.

1. tested negative battery post to the engine block = (.012 volts)

2. tested negative battery post to the body = (.017 volts)

3. tested engine block to fire wall = (.030 volts)

4. tested positive battery to output stud on the alternator = (.700 volts)

5. tested positive battery to the starter relay threaded stud = (.02 volts)


charging system voltage from alternator stud to negative battery post 15.2 volts and postive and negative post on battery 14.4 volts

The interior lights still flicker any ideas?

got .8V drop from alt "batt" terminal to battery positive post which is high (I'd do some cleaning) but not the flickering prob. I'd say R&R the brushes (1st, they're cheap) or maybe the whole alt

Check the condition of your ground wires , That could possibly be contributing to the problem