Weird Electrical Problem Please help!!!

[DportTalon]

ok gonna be a bit long here so here it goes..

let me first tell you what i have in my car just so you get an idea of whats in my car.. i have a optima yellow top battery, a rockford power 851s and rockford 500x amps in my car. thats just to let ya know what i have.

i went out to my car a few days ago and when i got in i noticed the dome light didnt come on.. go to turn my key, nothing no turn over.. no lights come on no power period.. i pressed in the dome light too see and nothing.. my first thought was hmmm i killed my battery somehow.. while sitting there the dome light turns on... so i turn the key and car starts right up.. drive to work runs fine nothing seems out of the ordinary.. go to lunch at work nothing wrong.. get home turn key off and no power again.. then a few minutes later the power kicked back in... so it seems like right when i turn my key off or when the car is sitting not running i dont always have power... this is getting very annoying because it keeps reseting my deck and what not.. one other note that might help determine what is wrong.. is when the car is on whether the amps are on or i have the face off and the amps are off.. all my lights in the car flicker.. so that is one odd thing that happens almost forgot to mention that.. other than that nothing is out of the ordinary

any help would be greatly and ut most appreciated.. thanks
bryan

 

[Defiant]

Make sure your battery is bolted down, you have an insulating cover over your positive terminal, and clean the battery posts and cable rings for starters. Get those little felt rings to put under them, and spray them with that red stuff for battery terminals. They're all on the battery rack at Wal*Mart, on the skinny end, and will cost about five bucks.
After that, check your fusible links on the battery cable (just replace them) and in the fuse box. Another ten bucks or so.