On more than one occasion, in more than one 1.9 system, I have run plain
water and the low coolant light operated normally.  I have seen posts
about improper coolant mixes causing the light to blink but I've never
been able to get that result.

Mike

John Rodgers wrote:
> If I understand how the system works, the circuit samples the resistance
> of the coolant. Depending on temperature, it takes a bit of time for the
> sampling to take place. Once done, if the resistance is correct, the
> light goes out. If not, it continues to blink. An open circuit condition
> would be one in which there is no coolant between the terminals in the
> sensor - like perhaps all the coolant leaked out. That would be an
> infinite resistance, and the light would blink. If the coolant/water
> ratio is not correct, the resistance would not be correct for the
> circuit, and the light would blink. It is possible that a weak or
> failing component could affect the resistance, or a ground could be
> developing corrosion and thereby increase resistance and in so doing
> cause the like to blink.
>
> My $0.02
>
> John Rodgers
> 88 GL Driver
>
> Kim Springer wrote:
>
>> So, lately I had the blinking light behind the temp needle come on
>> randomly, but more often when cold..  No overheating, everything seems
>> to be fine.  The coolant level looks fine to; no loss, no low level.
>>
>> Please explain.  Yes, I'm too lazy on Turkey day to look it up in the
>> archives.
>>
>> Happy Thanksgiving everyone,
>>
>> Kim Springer
>> 2WD '89 Tristar #7 White
>>
>>
>>
>>
>