Date:         Fri, 26 Jul 2013 16:51:21 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Do I drain coolant B$ removing sensor
Comments: To: Spencer Allen <spencervw@AOL.COM>
Content-Type: text/plain; charset="us-ascii"; format=flowed

>Beyond that though, you can mostly diagnose the blinker without
>removing the sender, as I'll describe in the next email.

This assumes you have blinking light but the gauge does not read
overheat.  Some '85s might have the early controller that will also
peg the gauge.

1) Observe the light as you turn the key on.  If it simply doesn't
stop flashing that's normally a gauge problem, and we'll make sure
later.  If it blinks for a couple seconds and goes out, then a short
time later starts blinking again,

2) shut the key off, unplug the sender and short the connector
terminals with a paper clip.  Turn the key back on.  If the blinking
does NOT stop and stay stopped, you have bad ground to the connector
or bad wiring from the connector to the controller module which on
the 1.9l is mounted on the cabin wall forward of the fuse/relay
panel, above the star grounds.  However,

3) if the blinking DOES stop and stay stopped you have bad contact
between connector and sender, dirty sender pins, or conceivably
coolant that is too weak or too strong to conduct properly.

4) Back to step one, if the gauge blinks and doesn't stop, then it's
usually a leaky capacitor inside the gauge.  It could be a bad
controller module.  Diagnose by removing the controller module.

Yrs,
d