Test Procedure

1. Wiring - Check connections on sending unit and rear of fuel gauge for tightness and lack of corrosion. Check for ground continuity on black and black/green wires at sending unit (2 wires, one connection).

NOTE:
Ground point for fuel gauge sending unit and fuel pump is underneath left hand side of headliner at the rear.

2. Multifunction unit - With an accurate-voltmeter measure stabilized voltage at disconnected green/black wire at sending unit or at rear of gauge (right hand gauge stud as viewed from rear of binnacle). Specification: 10.0 +/- .25 V with the ignition switched on. Replace multifunction unit if out of tolerance.

3. Gauge - Using a 0-500 ohm variable resistor (locally supplied) and an accurate ohm meter perform the following tests:

A) Adjust the variable resistor to 19.0 ohms. Connect one lead to the green/black wire disconnected from the sending unit and the other lead to vehicle ground. Switch on the ignition and wait two (2) minutes. The gauge should indicate in the full range.

B) Adjust the variable resistor to 270 ohms. Connect as above. The gauge should indicate empty.

C) Check several intermediate values as found on the table below:

FULL - 19 OHMS
3/4 - 38 OHMS
1/2 - 67 OHMS
1/4 - 116 OHMS
Reserve - OHMS
Empty - 270 OHMS

NOTE:
All values are plus or minus 5 percent.

Replace the gauge assembly if needle position does not match the appropriate resistance.

4. Sending unit - The sending unit must be checked if the gauge tests OK (Step 3). With a full tank of fuel, measure the resistance of the 7 sending unit with an accurate ohm meter (wiring disconnected).

Specification: 18.8 - 19.6 ohms. If not, drain fuel tank and remove sending unit.

CAUTION:
Use extreme care when transferring fuel. Use only approved fuel storage containers. Test the removed sending unit with an ohm meter using the values from the table in item # 3. There may be no breaks or opens as the float arm is moved from full to empty and vice-versa. Replace the sending unit if found to be electrically out of tolerance or mechanically damaged.

NOTE:
In cases of apparently stuck sending units or when replacing one with a new part, ensure that the float ball is snapped into the rod with the larger part of the ball facing forward (toward the front of the car).