I had a case recently on an 86 syncro where the foil connection for the
instruments, T14 on the diagrams,  was *very* dodgy.
Just barely touching the  T14  plug would maker the LED flash, or not.
Electrical contact cleaner there helped a little ..
Really needs a new foil IMO.

Scott

On 12/15/2013 2:21 PM, David Beierl wrote:
> At 10:22 AM 12/13/2013, Dean S wrote:
>> Hello all;ok I have the wacko flashing temp gauge syndrome which
>> magically
>> showed up  after a coolant flush...and replacement the coolant used was
>> Pentofrost SF....My guess its either and air pocket or a fill level
>> issue.
>
> You don't have to guess.  Stick a flashlight up to the pressure
> bottle and you can see the level if it's down.  If it's below the MIN
> marking the gauge should flash.
>
> IF this is the case, when you turn on the ignition you'll get the 2-3
> second flash which will then stop.  A few seconds later it will start
> up again and continue.
>
> If you get constant flashing from the instant of key on, it's likely
> the gauge or maybe the controller.  Unplug the controller (42 or 43
> painted on it).  If the gauge keeps flashing it's bad panel voltage
> or bad internal gauge capacitor.
>
> If it stops, plug the controller back in.  If it starts up instantly,
> bad controller.
>
> If it waits a few seconds to start up, key off, unplug the sender at
> the pressure tank and short the contacts of the connector, then key
> on.  If it still blinks continuously you've got open wiring somewhere
> between ground and the controller.  If it doesn't, you've got bad
> contact at the sender connector or dirty sender pins or conceivably
> coolant that's too strong or too weak.
>
> Yrs,
> d
>