Radio power wire question

[BANGEREXPO76]

Guys

I have a bad "memory" power wire in my radio harness because the person I bought it from cut the factory harness. Now when I hook up a radio. It will not store any information. i.e. radio stations, or pick up where it last left off on the cd. I have tried long and hard to figure out why that memory power wire is not working correctly. The radio will only power on if I put all the power wires together. But it will not hold memory. Take them apart and the radio wont power on at all which is very confusing. Any ideas???? Also. How can I wire a line in. I dont see anywhere to tap the fuse and send a new line up. Do I need to take the fuse box down in order to gain access to tap a wire in for power? Any help appreciated.


Banger

 

[Thermo]

banger, if you look at your wiring, there are 2 wires that you need to be focused on. You have a black/pink wire (black wire with a pink stripe on it) that is your switchable 12 VDC wire. The wire that you are more interested in is the white/purple wire. This is your 12 VDC constant wire (for the memory. There is also a light green/purple wire (12 VDC constant), but that is the power wire for the amps and should have nothing to do with your memory issue.

I would measure the white/purple wire with the truck off and see if it truely has 12 VDC on it. If it doesn't, then I would be looking at fuse #6 under the hood of the truck. That is what will power this wire. I bet you will find that this fuse will be either blown or it has developed a high resistance and if you measure it while connected up to the radio, it will read low.

Now, not to question how you have the radio connected up, assuming you are running a new aftermarket radio, you should have the yellow wire hooked up to the black/pink wire and the red wire connected up to the white/purple wire. If you have them backwards, you can get the same indications that you are seeing.

 

[BANGEREXPO76]

banger, if you look at your wiring, there are 2 wires that you need to be focused on. You have a black/pink wire (black wire with a pink stripe on it) that is your switchable 12 VDC wire. The wire that you are more interested in is the white/purple wire. This is your 12 VDC constant wire (for the memory. There is also a light green/purple wire (12 VDC constant), but that is the power wire for the amps and should have nothing to do with your memory issue.

I would measure the white/purple wire with the truck off and see if it truely has 12 VDC on it. If it doesn't, then I would be looking at fuse #6 under the hood of the truck. That is what will power this wire. I bet you will find that this fuse will be either blown or it has developed a high resistance and if you measure it while connected up to the radio, it will read low.

Now, not to question how you have the radio connected up, assuming you are running a new aftermarket radio, you should have the yellow wire hooked up to the black/pink wire and the red wire connected up to the white/purple wire. If you have them backwards, you can get the same indications that you are seeing.

Thanks for the reply Thermo

I will check that #6 fuse under the hood. Now that you have opened my eyes I can most definately see it being blown. Probably touched something when the last owner was installing his system. Hopefully popping in a new fuse if blown kills the entire problem.

I have the connections correct even reversed them to be sure numerous times. Its just that the radio will not power on when the wires are connected seperately. But if I connect them all together the radio will power on. Just no "memory". So that was throwing me for a loop. Trying to find a work around without getting robbed at the electronic store.

 

[BANGEREXPO76]

Thermo

Are you speaking on a fuse in the truck or under the hood?

Thanks
Banger

 

[Thermo]

Banger, you are wanting fuse #6 under the hood of the truck. Not the one in the fuse box under the dash. It should be a 15 amp fuse. Keep in mind that you may also need to look for a 10 amp fuse in a mini fuse block under the dash as this is inline with the radio. I would say to pull the radio out and look at the white/purple wire and verify that you have 12 VDC there. If you have power there, then both fuses are good. No power, no memory.

 

[1koerner]

thermo is absolutly correct but a quick and easy way to do it (if thermo's way is confusing u) just run a piece of wire from a constant source (cig lighter pwr ect) and connect it to the yellow wire on your aftermarket hu ive had to do this to a lot of chevy's and a few dodges b/c they have no constant in the aftermarket harness for a hu

 

[BANGEREXPO76]

I thank both of you boys for the help.

Ok I will look under the hood at the fuses.
But when I look at the fuse diagram for my truck. it doesnt show the number 6 fuse in the power distribution box or the mini fuse box under the hood as anythig related to radio. Maybe Im reading it wrong.

http://www.motorcraftservice.com/pubs/content/~WOVEXD/~MUS~LEN/41/97exdog1e.pdf

pg. 137

I have testers so I will make sure I go in and check that white/purple wire for 12v.
Im pretty sure there is no fire on that line but I will make sure. The previous owner hacked the harness up pretty good.
My other issue is if I cant get fire on that w/p wire. Can I just stick a wire in the fuse space for the cig lighter or other constant source and slide the fuse back in to hold it? Or does the fuse box have to come down. I dont see any where to put an actual fuse tap like in the old school cars. Let me know what you think. Thanks again. help is much apprciated.

 

[BANGEREXPO76]

Thermo,

The #3 10a fuse in the little fuse box on the side wall near the power distribution box was blown.
Popped a new fuse in, seperated the power wires and everything is working like a charm.
Been trying to get to the bottom of it for 5 years.
Thanks for pointing me in the right direction.
Much appreciated.

Banger