1993 F150 XL. Factory am/fm radio had an issue where the volume would increase from where you set it to very high and then back down.

Replaced it with a Pioneer Digital Media Receiver. Single Din. Also used the Scosche wiring adapters so I would not have to cut the factory harness. I soldered the wires rather than use crimp connectors.

The radio lights up, selects stations, bluetooth streaming, etc. Absolutely no sound out of any of the speakers. I triple checked my connections. they are essentially color to like color. Used my mutli-meter and checked the solder connections and they are all perfect.

Any ideas or things to try? While the audio control was goofy in the factory radio, the speakers did work fine.

Thanks.
Mike

 

There is a warning in the fine print about the requirement to use speakers over 50W and between 4 and 8 ohm impedance. It says do not use 1 to 3 ohm speakers. Could the factory speakers be the issue? I have not replaced them.

 

Speaker impedance matching is vital to any solid state audio device living a long life. Even so though most aftermarket stereo's suppose factory speakers will be used and should be able to accomodate your existing speakers.

Unless your Pioneer is vastly different from the typical replacement upgrade stereo all should be good. The complete lack of any signal even operating noise suggests the unit itself might be the cause?

 

Thanks for the reply.

The only noise I get is a slight pop from the left front speaker when I turn on the head unit. Other than that, not even static, hum or anything. Before I have to cut the radio harness off and return the unit, I figured i would try the battery test on each speaker lead to ensure the vehicle wiring goes where it is supposed to.

Short of that, I can't think of anything else to try.

 

Testing results:

1. I connected the scosche harness to the radio. Then connected the grey connector only (power). I then connected an 8 ohm speaker from the house to the right rear pins on the black scosche connector. There was sound from the radio.

2. I pulled the right rear speaker and ohm'd it out. 4.7ohms so they should be ok.

3. I verified the oem wire colors are matched to the harness correctly. They were.

4. I used a AA battery with wires on each end and touched them to the vehicle speaker leads through the pioneer plug/scosche harness combo. I could hear the scratching pop noise on the appropriate speaker for every connection.

So, I can conclude the receiver is not at fault. The speakers seem to be within ohm spec and should work fine. The wiring is correct to each speaker and to the harness.

What else is there that I could possible check?

I could run new wires to the factory speaker locations but that is a lot of work and it was a whopping -2F outside today. My fingers went numb during these tests.

 

I'd try the same test but on the entire speaker wiring system, all speakers in place and connected.

At the stereo's connector leading into the chassis speaker wiring do you Ohm test. Typically its safe to assume the DC reading of a speaker will be about 2/3 of its nominal impedance which will be helpful determining your system's total impedance load the stereo is seeing.

After that the only thing would be something in the wiring system when connected is causing a short of some sort.

Sorry I can't be more helpful but trying to diagnose or troubleshoot over the 'net ain't easy for me.

 

Sounds like a short. That pop u hear is a giveaway. Test all 8 spkr wires for resistance to ground as well as impedance of each spkr n u will find it.
Be sure to ohm out each speaker through the harness wiring as that will test the entire circuit not just the voice coil

 

I tried to follow both your instructions and here are the results.

Test through whole system (multimeter probe touching the speaker +/- on the vehicle black connector):
Left Front 5.0 ohms
Left Rear No reading
Right Front 5.1 ohms
Right Rear No reading

Test each to ground (multimeter probe touching the speaker + or - on the vehicle back connector and multimeter probe on chassis ground. bare spot on door hinge):
Pin 1 (Brown/Pink) No reading
Pin 2 (Pink/L Blue) No reading
Pin 3 (Black/White) 28.2 ohms
Pin 4 (White/L Green) No reading
Pin 5 (Blue/Orange) No reading
Pin 6 (Pink/Green) No reading
Pin 7 (Black/White) No reading
Pin 8 (Orange/L Green) 37.8 ohms

Am I interpreting the results correctly to assume I am dealing with rear speaker pin 3 and 8 having shorts?
If that is the case, I would assume I could disconnect those wires in the harness, connect the receiver and I should now have sound out the front speakers?

 

That's correct. If u disconnect those two wires u shld have sound. The next step wld be to find out why they r shorted. Likely causes wld be a pinched wire or tensil leads on a spkr shorted to ground.

 

Found the shorts. Sound worked fine after I rewired that. Thanks!

 

Glad I cld help. Ford on brotha

 

What caused the short---any idea?