I've been having electrical problems on my '92, F-150, 4.9L for going on nearly 3 years, maybe 2..

It started with the Fender-mounted Relay, after I changed it, things got better, i.e. My gauges would read higher and higher after using headlights, blower for air, holding the brake pedal, (when the brake lights would come on), anything that would start drawing a High Load. I have checked all grounds. Cleaned up aa few and replaced 2 that were bad. Anything electrical runs fine, as long as there is no load on the system, yet, I replaced my 2G alt. with a 3G, new brushes. i could sware I checked the volt reg. on it, and it tested good. the fender mounted relay is brand new..well 3 years old now..Is there some way of testing the Relay for high resistance..I didi it once before, but maybe I didn't do it right, just frustrated with this electrical problem.

I'm lost. I just know I hate this..and wish it would have never of started. I know that some days, the volt gauge in the dash is either on the "R" or on the "L" of normal, and the multimeter reads 14.50, 14.60, regardless it does that.

If anyone can point me in the right direction of checking resistance in some area of wiring I maybe missing when I am testing, I sure could use the help.

Thanks for looking!