Switch Performance Check
WARNING: This page is about a different car, the 1994 Mercury Tracer and 1994 Ford Escort. However, it is still accessible from the selected car via links, so may be relevant.
Check switch in ON and OFF positions. Install breakout box, leaving PCM disconnected. Turn ignition on. Measure voltage between breakout box test pin of switch being tested and ground. Switch should function as follows:
- BOO Depress brake pedal to close switch. Battery voltage should be present.
- DEF Turn rear defroster on to close switch. Battery voltage should be present.
- HDLT Turn headlight on to close switch. Battery voltage should be present.
- VST Switch is closed when engine is cranking. About 9 volts should be present.