No Subwoofer

[andyb5]

At my wits end here, hoping you guys can help me out.

I have a subwoofer that recently stopped playing. Other than no subwoofer, the head unit (Pioneer AVIC F700BT) functions normally. The problem is constant regardless of the input audio source - radio, CD, USB, or iPod.

So I went ahead and started troubleshooting from the back of the car forwards. The sub isn't blown (measured ohms with DMM) and I checked the speaker wire from the amp to the sub for continuity, all good.

Next, I verified there weren't any breaks or internal faults in my RCA cables and everything there is fine. So my conclusion was that the head unit is not outputting a signal for the sub. Even with a DMM on the RCA outputs on the HU, there is no signal to be found.

So after so searching online, I checked for breaks in the RCA shielding inside the Pioneer unit by following these instructions - http://bcae1.com/images/rca/temporaryrcashieldrepair.html and the shields are ok. And that's where I'm at.

Help please!!

[floggingmike]

Is the amp getting power and properly grounded?

[andyb5]

Amp is getting ~14.4 volts, and the ground is solid. No blown fuses anywhere either.

I ordered a spare harness so I can test the system with an older Pioneer headunit I have.

[floggingmike]

hmm....any chance you could swap the amp out to test? is there absolutely no sound coming out of the sub? you said theres a signal from the hu through to the rca's, and that the speakers itself works, so that has me thinking it may be the amp.

[andyb5]

There is no signal from the HU. I verified that the RCAs themselves are fine, but the amp isn't receiving a signal.

[T-5Bandit]

Sounds like the RCA outputs on the headunit are bad. To test, try connecting the RCA wires to another pair of outputs on the headunit and see if the amp gets a signal.

[andyb5]

Will do, thanks!

[floggingmike]

oh woops! Yeah check the RCA outputs as bandit said. Did you test with the other headunit yet?

[BrickCity242]

If you have a home audio receiver with rca output and an extension cord long enough to reach your car. You can use it to test the amp. Would seem easier then installing a head unit to test.

[BEJinFBK]

A 3.5 mm headphone to RCA adapter cord makes any handheld device an audio source, too.

[floggingmike]

Any luck?