Bought used 96 Suburban 2500 that will be occassionally driven to tow my travel trailer and the radio will only work sometimes on a low volume level. If I turn it up some it will either go out or blast at high volume. There seems to be a "dead" zone on the low-med volume settings. How hard is it to replace the head unit? I was considering getting a junk yard replacement unless this is a common problem (or they are problematic) then which aftermarket heads are easily to swap into and are affordable. I am not an audiophile and a good stock system will suffice my needs. I have considered swapping out the speakers though if someone has some recommendations for something that are compatible and not expensive.