When you quickly turn on the key and start the engine, does the light
stop blinking for a few seconds and then come back on? If so, there is
likely a problem at the main tank where the sensor is. The cable may be
loose, the connection may be dirty, the sensor may be bad or dirty/ or
the coolant in that tank may actually be low. The overflow tank is not
where you need to check. You must open the engine cover and check the
main tank. Verify the level by unhooking the small hose from the cap and
opening the cap, slowly if the engine is hot. Slowly add water to the
top. Put the cap back, start the engine and check for flashing..

If the light flashes continuously even when the engine has just been
started the fault is often in the temp gauge itself. A simple test for
this on 86+ models is to remove the coolant level relay from relay
socket #3. This relay will have a large 43 printed on the end of it.
(some late model versions have 42 on them instead). If the flashing
continues with this relay out, the cause MUST lie in the dash wiring or
instrument cluster.

Mark

Keith Pike wrote:

>Just  fired   up the  bomb and  the  water temp light  stays on  blinking;
>heaters  work and  o/f tank is  up. what to check next?
>TIA
>Keith, NL
>Canada
>
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