Date: Fri, 18 Feb 2011 14:44:45 -0500
Reply-To: Dagbear@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rico Dagastino <Dagbear@AOL.COM>
Subject: Re: blinking coolant light solution
Content-Type: text/plain; charset="US-ASCII"
I replaced the coolant tank on my 87 Vanagon about a year ago. I arrived
with a new coolant level sensor. When I flushed the cooling system and
replaced tank/sensor combo the low coolant level warning light would blink
until the coolant warmed to operating temperature. I replaced the low coolant
sensor control unit and checked the wiring for continuity and excessive
resistance. There was none. All of the grounds were cleaned. Still, the
light continued to blink until the coolant warmed to operating temperature.
I replaced the female spade connectors on the sensor. Still, the coolant
light blinked until the coolant warmed to operating temperature. By
eliminating all other causes I reasoned that there must be excessive resistance at
the probes immersed in the coolant. I further reasoned that increasing
the surface area of the probe ends would overcome this increased resistance.
I took two very small gauge spade connectors and cut off the cylindrical
portion which is intended to be crimped around the wire. I took those two
cylinders which were about 1/4" in length and slipped them over the ends of
the probes making sure that they were just long enough to cover the probe
ends but did not extend further. I tightened them against the probes with a
crimping tool and soldered them to the ends of the probes. When I
returned the sensor to the tank and turned the key to the "on" position the low
coolant indicator light functioned as it was intended. It blinked for a few
seconds and then was dark. It has continued to function properly for
months.
By increasing the surface area of the probes slightly I was able to
overcome the resistance problem which caused the indicator to continue to blink.
I checked the condition of the probes recently and found them to be in
pristine condition. This was an inexpensive fix for a problem which defied
solution.
Rico Dagastino
Memphis, TN
In a message dated 2/13/2011 11:32:53 P.M. Central Standard Time,
gfs@GREGORYFSMITH.COM writes:
The past couple (ok, few) days I've had a blinking coolant light despite
having a full pressure tank and good level in the reservoir. Finally
got some time today and pipetted some coolant form the pressure tank and
removed the level sensor. Sure enough the probe tips were coated with a
dark slime. Wiped it off and all is well.
Gregory Smith
'88 Vanagon GL
Smith Design Studio
Small Building Company
Olympia, WA
360-239-0429
gregoryfsmith.com