Wiring sound systems!

[83 WB_Ute]

Only thing I can think of is that the memory wire is intermittently/randomly losing power, hence losing memory.

What fuses did you hook into to power it?

Thats exactley what I think is happening! I did some searching this morning and found that the 12volt power wire that I have connected to the fuse box does not lose power (test lamp stays on..) when the key is turned to Accessories, On or Winding the motor over.. :/
I had a fiddle with the cd player aswell, put the settings/radio stations in and then turned it off, then back on. It kept the memory for about 4 times and then lost it on the 5th! :(
That makes it even more weirder :/

The ignition/accessories wire is attached to the cigarette lighter fuse on the top left hand side of the fuse box, while the 12volt constant power wire is connected to the bottom right hand side of the fuse box (off the top of my head, I don't know which fuse..)

I moved the earth this morning to a better spot, and I did notice that when the glovebox was open (head unit is mounted in there..) it held the information, but as soon as the glovebox was closed and the ignition turned off, it lost it.. :/
Any idea as to why it's doing that?

I have found with late model head units on old cars to hook the 12v constant straight to the battery with an inline 15amp fuse, because if you turn them up with an amp or somtimes on there own its to much for the old fuses espiecally the original 3 amp radio fuse. i have always used the cig lighter fuse for acc as it also uses a large fuse. also did you scrape the paint off when you connected the earth?

I'm considering doing that with mine now, cause I'm having shitloads of problems with it the way it is now :/

Yep, the cigarette lighter fuse is what the ignition/accessories is connected to. I'll have a look and get back to you as to which the power wire is connected to..

Yep, I took the metal right back to bare metal and them connected it up. I repositioned the earth to a better spot this morning aswell..