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HVAC Control Power and Ground Circuit Troubleshooting
HVAC Control Power and Ground Circuit Troubleshooting
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1. |
Fuse check:
Fuse check
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?1. |
Check the following fuse.
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Fuse |
No. B1 (7.5 A) |
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Location |
Under-dash fuse/relay box | |
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Is the fuse OK?
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Replace the fuse, and recheck. If the fuse blows again, repair a short in the No. B1 (7.5 A) fuse circuit.? |
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2. |
Open wire check (IG2 A/C line):
Open wire check (IG2 A/C line)
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?1. |
Disconnect the following connector.
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?2. |
Turn the ignition switch to ON (II). |
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?3. |
Measure the voltage between test points 1 and 2.
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Test condition |
IG ON (II) |
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HVAC control unit 32P connector: disconnected |
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Test circuit |
IG2 A/C |
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Test point 1 |
HVAC control unit 32P connector No. 17 (LT GRN) |
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Test point 2 |
Body ground | |
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Is there battery voltage?
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The IG2 A/C wire is OK. Go to step 3. |
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Repair an open in the wire between the No. B1 (7.5 A) fuse in the under-dash fuse/relay box and the HVAC control unit.? |
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3. |
Open wire check (GND line):
Open wire check (GND line)
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?1. |
Turn the ignition switch to LOCK (0). |
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?2. |
Check for continuity between test points 1 and 2.
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Test condition |
IG LOCK (0) |
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HVAC control unit 32P connector: disconnected |
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Test circuit |
GND |
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Test point 1 |
HVAC control unit 32P connector No. 19 (BRN) |
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Test point 2 |
Body ground | |
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Is there continuity?
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Check for an open in the wire between the HVAC control unit and body ground. If the wire is OK, check for poor ground at G506.? | |