I've recently had my share of problems with a blinking coolant light. I
have done everything I could think of to do:

1. New pressure cap (but it's Meyle brand, so a better one is next)
2. Replaced the gauge with a re-capacitored one David B did for me years ago
3. Cleaned all the terminals and finessed the connectors on the foil.
4. Made sure grounds were in fact grounds.
5. Made sure the coolant was as full as possible, and was mixed properly.

It would not stop blinking at some point on a trip as short as three of
four miles. I ended up jumping the connector so that the light will at
least stay off, and it does. I have all new hoses and tank, and no other
leaks so I am not worried about the coolant going low on me.

Any ideas as to where to look next? Before I jumped the connector, it would
usually--but not always--start off without blinking, but after a few miles
it would begin. I have pulled over to check the coolant a lot and never
found it low.

Jim