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Blower Motor Relay: Testing and Inspection
Relay Test
Blower Motor Relay
The high speed blower motor relay is located in the relay and fuse block, which is attached to the back of the junction block, under the left side of theinstrument panel in the passenger compartment. Remove the high speed blower motor relay from the relay and fuse block as described to perform thefollowing tests:
1. A relay in the de-energized position should have continuity between terminals 87A and 30, and no continuity between terminals 87 and 30. If OK,
go to Step 2. If not OK, replace the faulty relay.
2. Resistance between terminals 85 and 86 (electromagnet) should be . If OK, go to Step 3. If not OK, replace the faulty relay.75 5 ohms
3. Connect a battery to terminals 85 and 86. There should now be continuity between terminals 30 and 87, and no continuity between terminals 87A
and 30. If OK, see Relay Circuit Test in the Diagnosis and Testing. If not OK, replace the faulty relay.
Relay Circuit Test
1. The relay common feed terminal cavity (30) is connected to the ground side of the blower motor. There should be continuity between the ground
circuit cavity of the blower motor wire harness connector and the relay and fuse block cavity for relay terminal 30 at all times. If OK, go to Step 2.If not OK, repair the open circuit to the blower motor as required.
2. The relay normally closed terminal cavity (87A) is not used for this application. Go to Step 3.
3. The relay normally open terminal cavity (87) is connected to ground. When the relay is energized, terminal 87 is connected to terminal 30 and
provides a direct path to ground for the blower motor. There should be continuity between the relay and fuse block cavity for terminal 87 andground at all times. If OK, go to Step 4. If not OK, repair the open circuit to ground as required.
4. The coil battery terminal cavity (86) is connected to the ignition switch. When the ignition switch is placed in the On position, fused ignition
switch output is directed from a fuse in the junction block to the relay electromagnetic coil to energize the relay There should be battery voltage atthe relay and fuse block cavity for relay terminal 86 with the ignition switch in the On position. If OK, go to Step 5. If not OK, repair the opencircuit to the junction block fuse as required.