This is a common problem. The trick is to figure out what is and isn't
possibly causing the flashing. With your year the simple experiment is
to pull the relay marked "43" out of socket 3 of the main relay/fuse
panel.  (sometimes it has 42 written on it instead of 43) This relay
reads the coolant level reading from the tank sender and blinks the LED
if the level reading is low for more than a few seconds. Pull this relay
and see if the problem stops. If it does, that means that the coolant
level circuit is causing the blinking. If it still does it with the
relay out, the problem is in the dash, not in the engine compartment.
Let me know what you find.

Mark