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Home >> Plymouth >> 1978 >> Arrow Base, Automatic Trans >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Auto. A/C Systems >> Testing >> Blower Master On-Off Switch

Blower Master On-Off Switch

Test this switch by applying 7-9" of vacuum from an external source and checking for electrical continuity. Switch should open at less than 3" of vacuum. Internal resistance of switch can be checked by measuring voltage at blower motor when system is in A/C-high blower. It voltage is low, and it can be corrected by replacing the master switch with a jumper, the switch should be replaced.

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