The fan blower motor is not working and you need to find out why.
See if the following is of any help.
A Problem in the Blower Motor Circuit
1 . Check the No. 12 (40A) fuse in the under-hood fuse/relay box, and the No. 14 (10A) fuse in the under-dash fuse/relay box.
Are the fuses OK ?
YES - Go to step 2.
NO - Replace the fuse(s), and recheck.
2 . Connect the No. 2 terminal of the blower motor 2P connector to body ground with a jumper wire.

3 . Turn the ignition switch ON (II).
Does the blower motor run?
YES - Go to step 4.
NO - Go to step 17 .
4 . Turn the ignition switch OFF.
5 . Disconnect the jumper wire.
6 . Disconnect the power transistor 4P connector.
7 . Check for continuity between the No. 2 terminal of the power transistor 4P connector and body ground.

Is there continuity?
YES - Go to step 8.
NO - Check for an open in the wire between the power transistor and body ground.
8 . If the wire is OK, check for poor ground at G501. Connect the No. 2 and No. 4 terminals of the power transistor 4P connector with a jumper wire.

9 . Turn the ignition switch ON (II).
Does the blower motor run at high speed?
YES - Go to step 10.
NO - Repair open in the wire between the power transistor and the blower motor.
10 . Turn the ignition switch OFF.
11 . Disconnect the jumper wire.
12 . Disconnect the heater control panel 30P connector.
13 . Check for continuity between the No. 16 and No. 17 terminals of the heater control panel 30P connector and body ground individually.

Is there continuity?
YES - Repair any short to body ground in the wire(s) between the heater control panel and the power transistor.
NO - Go to step 14.
14 . Check the continuity between the following terminals of the heater control panel 30P connector and the power transistor 4P connector.


Is there continuity?
YES - Go to step 15.
NO - Repair any open in the wire(s) between the heater control panel and the power transistor.
15 . Reconnect the heater control panel 30P connector.
16. Test the power transistor (see Power Transistor Test ).
Is the power transistor OK ?
YES - Check for loose wires or poor connections at the heater control panel 30P connector and at the power transistor 4P connector. If the connections are good, substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel.
NO - Replace the power transistor.
17 . Disconnect the jumper wire.
18 . Disconnect the blower motor 2P connector.
19 . Measure the voltage between the No. 1 terminal of the blower motor 2P connector and body ground.

Is there battery voltage?
YES - Replace the blower motor.
NO - Go to step
20. Turn the ignition switch OFF.
21. Remove the blower motor relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 22.
NO - Replace the blower motor relay.
22 . Measure the voltage between the No. 3 terminal of the blower motor relay 4P socket and body ground.

Is there battery voltage?
YES - Go to step 23.
NO - Replace the under-hood fuse/relay box.
23 . Turn the ignition switch ON (II).
24. Measure the voltage between the No. 2 terminal of the blower motor relay 4P socket and body ground.

Is there battery voltage?
YES - Go to step 25.
NO - Repair open in the wire between the No. 14 fuse in the under-dash fuse/relay box and the blower motor relay.
25 . Turn the ignition switch OFF.
26 . Check for continuity between the No. 1 terminal of the blower motor relay 4P socket and body ground.

Is there continuity?
YES - Repair open in the BLU/WHT wire between the blower motor relay and the blower motor.
NO - Check for an open in the wire between the blower motor relay and body ground. If the wire is OK, check for poor ground at G301.
Nov 4, 2009 at 9:23 AM