So recently my ST205 has been acting up. While driving, the engine check, oil and overheat light turns on and off. So does the led for my car alarm. The dash just keeps clicking away and my car deck and subs turn on and off.
The car starts up and runs fine otherwise...

Can anyone advise me on what to do?

Start by checking your electrical connections, particularly the battery terminals. Corrosion can produce a weak connection. Usually a little sandpaper is enough to restore a clean connection, with dielectric grease to keep it that way.

^ What he said, especially the grounds...

Yep you have a loose ground

Thanks everyone! The problem seemed to resolve itself without me doing anything but I will check the grounds and sandpaper as suggested to prevent it from happening again.