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ElectronicsPete, Electronic Engineer
Category: Car Electronics
Satisfied Customers: 17318
Experience:  Over 16 years of experience installing and repairing electronics.
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I recently installed the Pioneer FH-X720BT in a 2005 GMC

Customer Question

I recently installed the Pioneer FH-X720BT in a 2005 GMC Canyon using the GMOS-01 harness. The head unit works fine when the car is still, but loses power when the car is moving. Power is restored when the car stops at a stop sign or light or parks. I have triple checked all of the connection and they all are good.
Submitted: 1 year ago.
Category: Car Electronics
Expert:  ElectronicsPete replied 1 year ago.

Hi there,

If the system only works when the car is stationary then it seems it may be getting power from the brake lights...

You will need to use a voltmeter to test the power supply wiring and trace it back to figure out what is wrong.

Customer: replied 1 year ago.
It works fine when the car is in park and the power is coming from the factory harness. It seems as though there may be a voltage drop when the car is in motion which is causing the head unit to turn off.
Expert:  ElectronicsPete replied 1 year ago.

Can you measure the voltage when in park position and when the car is moving?

You may need a second pair of hands to assist with this.

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