Re: ford cd stacker-help please!
ER1 would be an error code, but without knowing the model of the car it is a bit difficult to guess what it means. I am assuming that you have the boot mounted stacker. Try the easy things first - remove the CD cassette from the stacker, and try a different CD. If that doesn't work, I would disconnect the stacker, and reconnect it in case you have a dud connection. After this, I would be checking if power is getting to the stacker - they often have an in-line fuse - you may have to grab someone to give you a hand to check for 12V there.
After that, it gets a tad harder - I would check the connector at the back of the head unit to the stacker - but this will probably involve removing unit from dash (unless you have super long triple jointed fingers!).