If the coolant LED is flashing all the time, it is quite possibly a
problem inside the actual gauge itself. There are some electronic
components in there whose job it is to flash the LED a few times
whenever the key is turned on. One of these goes bad and makes the LED
blink even when it shouldn't.

There are other possible causes that can be easily eliminated first. The
LED is designed to flash for 2 possible fault warnings. High coolant
temps and low coolant level. On 1985 models you can isolate the gauge as
follows.

In the dash below the instrument cluster is a 2 pin connector with 2
wires in it. One is black and the other is yellow/red stripe. Unplug
this connector. This removes all sources of signal to the temp gauge. If
the LED continues to constantly flash with this connector unhooked then
the problem is in the gauge and you should replace it.

83/84 models have slightly different wiring and the above method won't
work. The wires have different colors and are connected differently. 86
and newer are considerably different and a different approach is needed.
If anyone needs help with a different model year just ask.

Mark

Michael Wagner wrote:
>
> Folks -
>
> Need some suggestions.  The dreaded flashing red coolant light has come on in
> my '85.  The van isn't loosing any coolant, the main coolant bottle and
> overflow is full, everything appears to be fine.  I've replaced the sending
> unit that is on the main coolant bottle, so that isn't the problem.  Nothing
> else is obvious to me, so I need to start digging into the 'less obvious'.
> Any suggestions are much appreciated.  I know I'm not in any danger from this
> condition right now, but in the even that the main bottle ever does loose
> coolant, I'd like to be aware of it.  And besides, the flashing red light is
> just plain annoying.
>
> Thanks for your help.
>
> Mike W.