Dim bulbs and grounds
No, I'm not talking about your sister....mine maybe
One reason your lights may not be getting full juice at lower rpms is sort of related to your alternator/regulator. Many times you don't have a good chassis ground in your electrical system.
Right now, you have a positive battery cable going to your starter solonoid, then from there to the starter. OK now, think of where your
negative battery cable goes. That's right. It goes to a bolt on the engine block. How do you have a chassis ground? Sometimes, if you still have your original negative battery cable, there is a lug in the middle of it that usually gets held by one of the voltage regulator bolts. Does your car still have this chassis ground? Does it have
any chassis ground? If you have replaced your cable, probably not! Without a good chassis ground you are going to have all sorts of electrical gremlins. You'll get feedback (sneak) circuts, blowing low-amperage fuses, dim lights, ....
I had a problem with my Cougar having its lights pulsate at low RPMs. That is a sign of a bad regulator, right? I was also blowing light bulbs. One night I burned out just about every bulb in the car! I thought the regulator had stuck. I replaced the regulator. Still pulsate and blowing bulbs. Hmmmm. After finally exhausting all of my options, I ran another ground cable (short battery-type cable) from the engine block grounding bolt to a bolt on the front frame rail.
No more pulsing lights!!! See, the
regulator wasn't getting getting the proper voltage that would have triggered it to stop charging.
Give this a try!
Cougrrcj's tip line
Tip # 208
