On Mon, 14 Oct 1996 12:02:01 -0500 Bo Kersey <kersey@outdoortech.com>
writes:
>At 11:24 AM 10/14/96 -0500, you wrote:
><<SINIP>>
>>John,
>>
>>Your coolant light will blink if you do not have the proper mix of
>>coolant and water.  It will also blink if your fluid level is low.
>>
>>Just a thought.
>>-- 
>>Hotch
>>hotch@netaxs.com
>
>The sensor is simply a level sensor, not a magical glycol sniffer.
>>
>Bo Kersey
>'89 Westy - 65k miles
>
 The level sensor "senses" coolant level , not with a float/ switch
arrangement, but with two metal probes . When coolant level falls below
these probes for about ten seconds conductivity is lost and the LED
flashes and the gauge pegs. Using a decade-resistance box I found that
our 85 reacts this way at over 150,000 ohms between the terminals of the
sensors plug. I can see how this conductivity could be affected by high
anti-freeze (i.e. low H2O ) ratios. 
"What if I live in a cold clime and needed a higher ratio than the sensor
will tolerate?" you exclaim!? I would try an external resistor in
parallel to the sensor. I would start with about a 300k ohm. This would
lower the overall resistance into the acceptable range but not interfere
with the intended function (hopefully).
Good luck
ken lewis
kdlewis@juno.com