The UK quattro Network

Audi ur-quattro 10V WR, WX and GV Engines
Checking the full load switch

See the notes on page 25-21

• Connect the ohmmeter to the contacts on the full load (WoT) switch
• Set the protractor to 0°
• Open the throttle slowly
• The ohmmeter should show 0 ohms and open to infinite ohms at 55° to 50° from the idle position

NOTE: The last test differs from Audi's documented tests, e.g., D 000.5147.00.00 frame 25-22, the wiring diagrams at 000.5755.52.00 Diagram 13 track 51, etc., that uniformly document this switch as "normally open". It is in fact normally closed and actuates the solenoid valve by default when the ignition is switched on. When the throttle opens sufficiently, the switch opens and deactivates the solenoid.

If the test fails, adjust or replace the switch. Adjustment may involve loosening the mounting screws - usually very difficult - or simply bending the actuating lever on the microswitch. Always check function with full throttle travel - it is easy for the levers to fall behind the operating post on the throttle valve lever or even jam against the post, holding the throttle open.

It is especially important that the full load switch, once opening successfully at around 55° to 50°, does not close again at full travel.

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