Problem anyone had?

[Wrcampbell]

My 94 1500 5.7 has been having a voltage drop problem now for a few years and it seems to be getting worse over time. I purchased this truck and it hasn't had any modifications. I have replaced the battery and alternator and checked both battery cables for voltage drop. Haven't found anything out of normal that i can tell. Voltage gauge goes from around 14 to about 10 volts depending on what i am doin example turn signals, heater fan, etc. and the lights dim at night when do the same. So is there some other direction or place i should start looking at next? It seems there is no end??? Any help would great!!