[123rmp]

A few things that might point you toward one system or another or toward wiring or other issue -

Does it happen all the time or it just starts up for some reason ? Once it starts how long does it do it or does it ever stop ? When it happens is the pulse occurring regularly as in every X seconds or seemingly random, etc.? Is the pulse a dimming or brightening of the lights? Does the frequency or intensity of the pulsing have either an inverse or direct relation to the engine RPM or any other action (e.g., does turning on the headlights or other system change the pulsing frequency or intensity)? Does the measured voltage level anywhere in the system pulse with the visible pulse?

Sorry to be playing 20 questions....just seeing if there is any lead to follow . Sometimes it's the one stupid question somebody asks that beaks the case....sometimes.

[cv70chall]

See replies to your questions:

Does it happen all the time or it just starts up for some reason ?
-All the time.
Once it starts how long does it do it or does it ever stop ?
-Occurs only while engine is running.
When it happens is the pulse occurring regularly as in every X seconds or seemingly random, etc.?
-It's a regular dimming pulse- occurring on all head/ tail/ parking lights, instrument panel lights and radio. Does the frequency or intensity of the pulsing have either an inverse or direct relation to the engine RPM or any other action (e.g., does turning on the headlights or other system change the pulsing frequency or intensity)? Does the measured voltage level anywhere in the system pulse with the visible pulse?
-Increasing engine RPM's seems to get rid of it- anything over 1400RPM approx. (I idle at 950-1000)
Voltage checked at alternator, VR, battery and appears normal.

What next?

[123rmp]

I believe before I did much more I'd put in a new alternator just to see what it does but that's me. If you have a backup unit or one you know is good you can borrow, I'd swap it just to see what it does.

If no change then.....
Have you measured the voltage at the lights when it pulses? I assume the voltage dips when it dims, so can you see what it dips to ? Somewhere voltage has to be dipping to get the dimming you indicate. You said voltage was measured at battery, etc and it's normal. I assume that means you do not see any dip in voltage whatsoever when it was pulsing? Is your volt meter capable of sensing the dip? I mean some meters may not be sensitive enough if the dip is quick.

If there is no voltage drop then I'm about out of ideas...clean connectors, good ground and known good parts are the things I know to look at. I know diagnostics leads you to assume certain things may or may not be suspect but if you're out of ideas I'd suggest you don't assume it's not a bad component based on diagnostics alone. Replaced one at a time w another component just to see....Alt, VR, Batt, are the suspects and maybe you did them all already, except Alt?. If you have done all then I'm about out of ideas.

I had an issue recently myself w ignition components and after meter readings, etc under the hood that were getting tedious, I just started replacing components that could go bad as I knew the wiring had not changed. It was the ECM (Orange Box). Everything I replaced that I know is good is now in the trunk as a roadside spare.