Rear camera

Now that I think I have my fridge problem well addressed, I have an issue with my old voyager(I think) rearview monitor. Here's what happens...upon start up of mh , I get an unreadable picture, its all lines and no picture. After 30+ miles, sometimes a lot more, I finally get seeable view. My first thought was a voltage/bad connection....I've done some checking on this but I probably need to really get into it because this is the only thing that makes sense. I was thinking my echo charger might not be maintaining my chassis battery up to par but upon start up, the alternator should supply more than enough current. I thought if someone else had a similar issue, they could share their solution before I start going wild on things.