At 08:37 AM 7/27/2013, ralph meyermann wrote:
>Hi gang! I recently installed new fuel tank and sending unit and with 12
>gallons approximately of fuel its showing about half a tank. Is there some
>adjustment I can do to calibrate it?
>Velma 82 na diesel westy

Check for 10.0 +/- 0.5 V between the ground pin of the temp gauge and
whichever of the other pins gives the higher reading.  If that's low
you've got bad panel supply, bad panel ground or bad panel
regulator.  Any of these will cause both temp and fuel readings to be low.

If that's not the problem, a bad ground will cause low readings.

Check your gauge calibration per Bentley page 90.20.  The formula to
convert VW1301 tester settings to ohms is (VW/2) + 10 = ohms, so the
high value is 35 ohms and the low value is 170 ohms.

Note:  According to Bentley up through '84 used different
calibration, 37.5/290 ohms.  However I think that's baloney.  I've
swapped '85 panel into '84 with no calibration change, and ETKA shows
the same sender p/n up through mid '87.

If the gauge calibration is off you can adjust it with some pain by
the toothed zero and span levers accessible through little holes in
the back of the gauge.  They are interactive, takes 3-4 passes to get
them right.  One moves the pivot point and the other changes the
spring tension.

Yours,
David