Component Tests and General Diagnostics

Fig. 1 Wiper switch continuity chart:

WIPER SWITCH CONTINUITY TEST
1. Check switch continuity using a suitable test lamp or ohmmeter. Continuity should exist at various switch positions between terminals shown.
2. On intermittent wiper systems, measure variable resistance between terminals 4 and 5, if intermittent wipe cycle does not operate. Resistance should measure 5600---8400 ohms with control knob rotated to full counterclockwise position and decrease to 100---900 ohms as knob is rotated clockwise.
3. If switch does not meet continuity and resistance specifications, it must be replaced. If switch performs satisfactorily, check wiring for proper continuity.

Fig. 2 Wiper switch circuit breaker test:

CIRCUIT BREAKER TEST
The circuit breaker is integral with the wiper switch and has a rating of 7 amps.
1. Connect wiper switch to tester, and adjust current draw until it equals circuit breaker rating. Leave switch connected to tester for 10 minutes and ensure ammeter reading remains at rated current. If circuit breaker opens, replace wiper switch.
2. With wiper switch still connected to tester, adjust current draw until it doubles circuit breaker rating. Current reading on ammeter should drop to zero within 15 seconds. If it takes longer than 15 seconds for circuit breaker to open, replace wiper switch.