Here is the situation:

Symptoms:

-Lights for instrument cluster, heating/cooling, and headlights fade in and out (especially while driving at high speeds)

-Radio works perfectly, no fading.

-Car starts perfectly evetytime so I know the battery is charging; this has been happening for about a month now and no signs of battery or starting problems.

-SRS light and battery light will come on randomly while driving (again, especially at high speeds).

Dealer claims voltage regulator and alternator is fine, as well as the belt on the alternator.

I have no idea what could cause the problem. I am goign in tommarrow to remove my V-AFC and scanner because they are wondering if my "after market" parts may be the problem.

Can anyone offer any suggestions?

 

like you said, put the car back to BONE stock and see if it still happens.

 

Check grounds. High speed/high vibration may cause certain grounds to loose contact, causing electrical cuts. But usually your engine cuts also when you loose a ground contact, but just an idea...

 

Is your V-AFC hardwired in (i.e. soldered)?

 

Nope, got a adaptec harness from Kenji

 

If its an adapter harness, unplug the VAFC. I am guessing something is wrong with it.

 

A similar problem happened with my car when the ABS light would come on, then the lights would fade etc., but then recently it went away

 

your battery? mind did that for month or 2 before it went out

 

Check to insure that your negative battery terminal is on solid. If you have anything wired to the terminal if it pops off during driving the car wont stall because
it will be running off the alternator but you can get a lot of weird electrical problems.

 

My mustang used to do that. It was the voltage regulator.
...and thats about the extent of what I know. sorry.

 

Check the Grounds on each side of the Engine bay.
1 near the ABS Pump on the Fender Skirt and the other on the opposite side near the windshield washer fluid.