How do I establish the cause of faulty a/c controls?

1996 ISUZU RODEO
67,000 MILES
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NISSIEN
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I have replaced a faulty blower motor but am unable to power it. It appears to be an electrical fault, however on testing, fuses appear satisfactory. I wonder if there is a faulty relay.

1 Where is the relay situated which governs the air conditioning controls?
2 How do you remove the front panel where the A/C controls are positioned?
I removed 3 fixing screws but the panel remained firmly in position
Jan 10, 2012 at 5:38 PM
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DOCFIXIT
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Check Main fuse and blower fuse in relay box and find heater/ac relay. Do you have a meter or test light?
Jan 10, 2012 at 5:51 PM
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NISSIEN
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Thank you. Could you please advise how to remove the panel where the A/C controls are positioned?
Jan 10, 2012 at 7:04 PM
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DOCFIXIT
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Do not think that is problem do you have a meter?
Jan 10, 2012 at 9:19 PM
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NISSIEN
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Yes we have 12v meter, a continuity meter, and an ac meter incorporated and in addition a 12v test light.
The 4 speed a/c control is now faulty. The 3rd was previously faulty but the system was efficient.
Are you referring to the 100A Main or the ECM Main labelled EB-27?
We have checked relays EB- 21 (A/C COMP.) EB-29 (COND.FAN) and appear satisfactory.
Jan 10, 2012 at 9:39 PM
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DOCFIXIT
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ON blue/white wire to blower motor is there 12v+ when heater/AC on?
Jan 10, 2012 at 10:01 PM
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NISSIEN
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There was no voltage reading.
Jan 11, 2012 at 12:11 AM
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DOCFIXIT
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Check fuses underhood relay box
EB-16 100 Amp
EB-4 20Amp
Jan 11, 2012 at 2:52 PM
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NISSIEN
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I have returned.It is a 20 mile journey.
Fuses appear satisfactory.
There is no power to the blue/ white wire.
I have been told that the speed regulator/ resistor may be faulty. If that is so would that effect the power to the blue/white wire?
Jan 11, 2012 at 5:46 PM
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DOCFIXIT
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No blower resistor provides ground through fan switch to complete circuit. was voltage checked at blower motor connector disconnected?
Jan 11, 2012 at 6:25 PM
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DOCFIXIT
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Also test fuses with meter looking not enough and need to know if power is feeding circuit
Jan 11, 2012 at 6:45 PM
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