Connect battery positive voltage to terminal A and ground to terminal B of the blower motor and verify its operation.
Mazda 6 Service Manual: Procedures for determining the location of a malfunction
System Wiring Diadram
PCM
1. Check the display of DTC U0121 and/or U0155, using the SST (WDS or
equivalent). (See DTC TABLE.)
2. Referring to the following table, determine the malfunctioning part of the
CAN system.
ABS/TCS HU/CM or DSC HU/CM
1. Accec and monitor the PCM MSG and IC MSGo ...
Mazda 6 Service Manual: Woofer inspection
1. Inspect for continuity between the audio amplifier connector terminals and
woofer connector terminals using an ohmmeter.
If not as specified, replace the related wiring harnesses.
2. Verify that there is battery positive voltage at the woofer connector
terminal A (4SD) or C (5HB) u ...