Way OT- car stereo/radio

Way OT I know, but- the radio in my 97 F350 went. It was an aftermarket job that came with the truck. Went to put in a used unit my son gave me that worked fine in an S10. Got the proper harness adapter and wired it up per instructions, and I've done these at least a couple dozen times over the years on older vehicles. I have power and ground at the plug to the radio itself but no sign the unit is powering up. No lights, no display, no nuthin'. The other one died after I lifted the bed and replaced a fuel pump. The previous owner had a backup camera that I disconnected as it died on me some years back. The thought came to me that the camera might have fried the old unit before I unplugged all that stuff, a pinched wire maybe. I can't find anything pinched and all the additional wiring for the amp and "thump/thump" stereo the kid had is long gone. Common sense says the new/old replacement I'm trying (a Walmart special) was toast before I tried it, but I don't know enough about post early 80's cars to know if there could be something else screwing me up.

Ideas? Power and ground both test good. There is one yellow wire that is supposed to be for the "memory" that is supposed to be 12v+ but I get nothing on that. I assume that's active with the ignition off, but nothing shows in that condition. I'm going to try to trace that back next, but it's gonna be real cold for the next few days. Just wondering if the lack of power to that yellow wire would keep the unit from turning on?

Just did one in a john deere tractor. The yellow one had to have power all the time or the radio wouldn't work. You can google the radio make and get a
wiring diagram.

Find a "hot with ignition off" source and connect the yellow wire from the radio to it.

If no fuseholder in the yellow wire at the radio, install when where you source your "always hot" power "just in case", just a couple of Amps is enough.

Once you get the yellow wire powered up the radio should come to life.

Okay, thanks guys, I also just found a video outlining the wiring. I misinterpreted the yellow wires purpose. It's what the red wire used to be for and the red is just there to recognize the signal that the ignition is on. Sheesh! Things were simpler back in 1978...

I'll have to wait till things warm up and trace that yellow wire.

If the radio has a digital clock it would need the hot at all times feed.

Yeah. Whatever happened to the days when black was the ground and red was the positive. Seems like I see a lot of black positive hot wires.

(quoted from post at 19:35:37 01/28/21)
Yeah. Whatever happened to the days when black was the ground and red was the positive. Seems like I see a lot of black positive hot wires.

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The color of the wire that's in question here is YELLOW, as an "FYI"!

Also a lot of aftermarket radios have a mini fuse plugged in to the rear of the radio chassis, it's not hidden but often overlooked.

(quoted from post at 02:58:43 01/29/21) Also a lot of aftermarket radios have a mini fuse plugged in to the rear of the radio chassis, it's not hidden but often overlooked.

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Yup, first thing I checked. I guess have to start thinking of this like it's 12/3 wiring and not 12/2! My old mind just gets " 'fused up" too easy with this new and improved stuff!

FWIW, had to charge the battery up anyway, so I traced out those wires. I think the previous owner, who was a BIG fan of Scotch connectors (which I've found to cut wires as often as make a good connection), screwed something up way up under the dash and lost power to that wire. By the time you get into the harness it's green/black and disappears into the darkness. I checked eveywhere the books and internet said it should come out, but never did find it. Maybe in the warmer weather I can pull the dash apart and trace it out. I did determine that if I got power to that pin the radio would in fact work. Took quite a while to figure it out because the radio power system ground doesn't seem to go back to chassis ground, but the ground in the harness works fine. Makes zero sense to me, but it is what it is. So I found a constant 12v source and plumbed into that and it works fine. Now I need to fix the 3 out of 4 speakers that are inop and get the manual for the radio off line. At least we got the clock set! :lol: