Q2 Check Stoplight Switch

- Connect Rotunda EEC-IV Breakout Box 014-00322 with Anti-Lock Test Adapter T90P-50-ALA or equivalent to the anti-lock connector on the anti-lock brake wiring harness.

- Turn ignition switch to RUN position.

NOTE: Do not apply brake pedal while performing this test.

- Measure voltage between breakout box pins 32 and 60.

- Is B+ present?

YES -- Replace stoplight switch or service circuit 511 (LG). Restore vehicle. Retest system.

NO -- Go to Q3. Q3 Check ABS Function