If you installed a trailer light set up you should go back and verify the connection or remove it to see it the problem goes away. I have had the same problem with other vehicles and yes the dash light are tied in with the tail lights.
On a 1999 GEO Tracker, a bad fuse can cause the headlights and dash lights to blink. A bad voltage regulator or alternator can also cause lights to blink and flicker.
dash lights looks like an engine
Check fuses or headlight switch
Blinking lights on dash and exterior lights may indicate a bad ground wire or a faulty headlight switch. Both would cause those problems.
replace fuse
There is no BCM in a 99 Saturn......2000 it's under the dash pad
The rheostat for dimming and brightening the dash lights.
Add oil.
To locate the dash lights fuse on a 1999 Honda Accord to find out if it is causing the dash lights do not work when you have the parking lights on after installing an after-market radio, check the owner's manual. You can also find a fuse diagram at most auto part stores.
by licking stuff
Probably a fuse, check to see if your horn works, really!
Are you sure that the dimmer switch is working?