If your coolant light is flashing either the coolant sensor is bad,
the coolant is low, or there is air in the system.
Regarding the buzzing, I may be wrong, but I seem to remember that my
87 GL would buzz when the coolant was low.  But that's been several
years and so I'm not entirely sure.

Warren in Santa Fe
88 Westy "Billy Bones"

>>From:    Sunshine <vwbusgirl@KC.RR.COM>
Subject: Re: flashing LED

YES indeed I meant to say that and the coolant is NOT low but the
sensor might be not sensing is all I can gather as I saw when it DID
and now it is hooked up and everything and sealed but just isn't
working properly because obviously upon starting the engine the coolant
is not hot and it's telling me that it is.
The thermostat is brand new.

Peace, Love & VW Grease,
Sunshine<<