Date: Tue, 31 Jul 2001 11:25:59 -0400
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Re: More Flashing Red Light mysteries
In-Reply-To: <F140JSFsxf4yp8ARf3s0000a7d7@hotmail.com>
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At 10:50 AM 7/31/2001, Mark Ingalls wrote:
>I haven't traced the wires back to the gauge. Does one of the level probe
>wires have a ground that could be cleaned? Or a lose connection via the
>foil wire behind the instrument cluster?
>
>I haven't heard on the list of anyone buying a new gauge, does anyone know
>if these are a dealer only item?
>
>Do the new gauges flake out in humid weather?
Quoting myself from last Friday:
>2) Unplug the connector from the coolant-level probe. Needle will either
>head offscale or stay put. If it heads offscale then the flasher circuit
>in the gauge is bad.
>
>3) If it stays put then it's still probably the gauge, but you need another
>test. If you can remove the control module do that -- if the gauge still
>flashes continuously it's definitely the gauge. If not it's the module.
>
>4) If you can't remove the module, open the panel connector shell and
>remove pin 14, with a double yellow/red wire on it. Plug it back in
>without that wire. If still flashing, it's the gauge, if not then the
>module. Put the wire back.
>
>If (since) it's the gauge, you have three choices: a) replace it, b) remove
>the faceplate (rivets) and internal circuit board (solder) and replace the
>aluminum (probably) electrolytic capacitor sticking out of the side of the
>board. Use a 16v or 25v tantalum cap of the same value, and observe
>polarity. Almost certainly this will fix the circuit -- now you have to
>put it back together. Or c) put a piece of tape over the light. If your
>test #2 made the needle go offscale you will still have this indication of
>low coolant (or overtemp -- up to you to figure it out, just as it would
>have been with the light flashing). If test #2 did not make the needle
>climb then your only low-coolant warning is the light.
and
At 10:19 AM 7/27/2001, TimcoWestyGMC@aol.com wrote:
>Thanks David,
>Finally found the control module (relay?) with your description of the
>location.
>With it removed, the warning lamp continues to flash.
>(DEFINATELY a faulty gauge?)
Faulty gauge or just possibly faulty regulator, should have mentioned
that. Input to the gauge (left-hand pin as you face the gauge front)
should be 10v +/- 0.5v.
The usual difficulty is that there's a blinker-test circuit in the gauge,
that shuts off when the big capacitor charges to a certain point. The
capacitor gets leaky over time and never charges up enough. When it's in
the marginal state it can be affected by humid weather making the circuit
board a little more conductive. A minimal fix (not tested) would probably
be to simply remove the capacitor, thus losing the test function -- but you
still have to take the gauge apart for that, so might as well replace
it while you're in there. I think that 5-56 machine screws are the right
size to put the gauge face back on (you'll have to check).
It's fiddly work but not really difficult if you can solder and are careful
and thoughtful.
David Beierl - Providence, RI
http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"
