Hey fellow F150 fans. I'm pulling my hair out. First, know that I'm relatively familiar with both the vehicle, electrical issues and radio installs. I retired from automotive a few years back and had worked as a tech at first, (cut my teeth on Fiats back when they were the worlds first biodegradable car), then service and parts management. Ended my career as a commercial parts pro for Advance Auto Parts in 2020.

To the problem. I had an aftermarket unit that I'd wired in all the requisite "Metro Sound" adapters. At first the problem started about 6 months ago. Left door speaker went out. I had replaced the speakers and figured maybe I had a connector come loose. Two weeks ago the whole darned thing went out. I figured what the heck, it was a cheap aftermarket anyway, almost ten years old, get another. I purchased the same unit on Amazon, figuring it'd just be pull the connectors and voila, shove it back into place and good to go. No such luck. In doing this I did a thing I hadn't done on the older unit and cranked the volume all the way up.

Here's where the weird part comes in. There was sound. So faint you barely hear it but both sides, low volume, almost imperceptibly there. So I put the old one back in and tried cranking it too. Yep. Same thing. Sound but I fart louder. My suspicion would be that there's a separate amplifier and in some threads I've seen there's one in the premium sound system of the day so I went looking for it. Didn't find squat. I cant be sure if it even has one. The VIN is 1FTDF1723VNC88295, if y'all have any resource that can verify from that, that it should or shouldn't have one. The fact that I have this very truncated signal getting to the speakers tells me it might and I just cant find it.

I have the wiring schematics for that year and model. It's an XLT with the only nods to comfort being A/C and power steering. 1WD work truck that doesnt even have carpet, just the rubber liner. All that said, I love the old b--stard. Enough so that at about 55 years old I put a new long blck in it myself. If you've ever done one you know what a b-tch that is. Working on a Van without a doghouse. That 8 ft bed is heaven though.

Things I've done. Wired directly to each of the two connectors for the sound system and bypassed the "Metro Connectors" Made sure the wires to power both constant and switched were getting juice. Made sure the ground was actually grounding, Those with a multi meter. All good there. Same results, signal but very low.

Big ? mark for me. Between the two connectors for the radio was a third wired in, has Ford part number, I think. Not connected to anything and yellow blocking plate covering the pin connectors. My thought is that this would have been the connector to an amp but they just block it off on the cheap ones without the premium system. There doesn't seem to be anything "jumped" between connectors so I'm counting that as a redundancy but checked the wires to it as well to see if there was anything that might have come undone. Doesnt seem to have and the durned thing worked just fine for almost 10 years.

I'm bumfuzzled. Any help younger minds and hands?

Thanks in advance from an old dude that now just tends his property, makes really cool stuff out of leather, loves his dog and takes his best friend dog fishing in a Jon Boat now again. To the brainiac with way more skill than me that figures this one out, if you have a dog, you get a well made collar for them. If you don't have a dog but you're a kinky sort, hell I'll make one for your wife/girlfriend/partner. I just can't not have tunes while rolling. I've attached a picture of that weird "goes to nothing connector

Thanks for trying any way we look at it.

Leo

 

Just to be clear, So what you're asking is what that plug goes to on the Metro connector? If so I can tell you that it does obviously look as though it goes to a factory amp setup as you can see the main hot and remote wires are spread off to the plug. However Metro is also notorious for makeing universal harnesses to fit different yr models as the one you have could fit newer or older models with different configurations. Or just different cars/trucks of the yr range provided by metro.

Other side of OE amp


Now as far as having a OE amp. If you have one it will be behind that black panel on the floor where the floor vents exit right above mounted towards the firewall between the floor and HVAC Controls (or just remove the hvac controls and look downward) if you have a amp it'll be there. I've included a pic of what the amp itself looks like. But tbh. If you want to find out if there's a issue with the factory harness etc. I would just disconnect one or all of the outputs on the radio going into the metro harness and run my own wires to at least 1 sound device and see your results there. If it plays as it should then you've got something going on in either the harness (metro), a bad amp (if you have one) or the trucks harness has something going funky in it. If that's not the case I would verify that you are in fact getting 12volts to the actual radio's harness by checking voltage at the radio's connector. Also be sure you have a good solid ground. I've had issues similar before where the OE ground won't good enough and run my own to a good solid clean metal surface. And volla like magic everything come back. Anyways, Hope at least some of this helps and keep me updated on what you figured out😎.

Amp from my 97 lariat

Plugs

 

Thanks V. I was asking what the heck the plug between the two factory connectors was. The one with the yellow insert. At this point it's kind of moot. I have run new wires to everything. Using two Add-A Circuit fuse connectors I'm sending new 12V feeds to both the head and now separate power amp. Both 12V constant and 12V switched. I'm also creating a new ground lug for all. Speaker wires have been replaced as well. So all the wiring is new and solid. Hook up will be today. I picked up a set of speakers that will likely be returned as those currently in the truck, like the head and amp are aftermarket. I installed them I think 3 years ago. I realized that if one or both had gone bad they would have damaged the head with right short (power wire rubbed through with speaker wire sending power back through the speaker circuit could fry it). This way, I've eliminated all the factory harness possibilities, the speakers themselves, any ground issues. We'll see what happens today when I connect everything. My last task at this point is deciding what 12V constant to go to. I want to stay away from any crucial circuits like ECU, lights, etc. Looking at the interior light fuse at present. May go to the underhood panel and knock off from there. Suggestions for the constant power would b appreciated. I'm just going to use the radio fuse for the switched. Just a side note, I happen to be a leather artisan. The door panels were getting rough at the door pull. Cracking, tearing and just looking crappy. I had some upholstery leather that is a great match for the interior. A little tricky getting that section of the door panel separated as it's those melted plastic connections on the back side. Heres a sort of before and after picture of the left completed and the right will be soon. I'm pleased with the results, wanna slap a few engineers for their genius way of doing things. Planned obsolescence. Gotta love it. But now my 97 beater work truck has better interior appointments than most Mark LTs.

The lighting makes them look different colors

Newly covered

waiting for repair
Why they put no escutcheon around the door pull is beyond me.