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Subject:Re: Wonky temp gauge
From:David Beierl
Date:Sat, 2 May 2015 23:47:57 -0400

At 10:32 PM 5/2/2015, Jeff Palmer wrote:
>Sounds like i now have a spare temp gauge to add to my collection :)
>
>Light doesn’t flash at all.  Just glows 
>faintly.  Temp needle pegs ‘immediately’ 
>which means starts rising immediately but takes 2-3 seconds to reach the top.

That's about as fast as that needle can 
move.  The bimetal element is bending as the 
heater heats it up.  Unplug your level controller 
(on the side wall above the star grounds in a 
1.9l) and test.  If the gauge still pegs, unplug 
the gauge sender back at the engine.  If it still 
pegs, unplug the panel connector and look for the 
gauge sender line being shorted to ground.

The gauge itself is just a heating element 
connected between the 10V+ screw and the sender 
screw.  There is no normal failure that would 
result in it pegging by itself, it needs to have 
something loading down the sender connection.

The blinker circuit is entirely independent of 
the gauge; it takes power from +10V and the 
skinny ground pin, and has a sense connection to 
the sender pin.  When voltage at the sender pin 
gets low enough it starts to flash.

If it does not flash for 2-3 seconds when you 
turn the key on, either bad power, bad ground, or 
bad blinker circuit, there are no other possibilities.

Yrs,
d

>Last year before gauge replacement the temp 
>needle pegged the same and the light flashed 
>continuously.  The foil connection is getting kinda grungy.
>
>So power supply or ground issue it sounds like?
>
>Thanks
>Jeff