My radio has a bad memory!

First of all, thanks to the help from these forums, my '91 Dodge Caravan now has a transplant radio w/ 4 newer speakers from a '94 vehicle. All works, except for the time- the radio forgets what time is set and won't keep time. Additionally, it forgets from time to time what radio station is what set at previously. A smaller minor issue is when power is turned off there is a "click" or "pop" from the speakers. Any ideas? Did I wire something incorrectly? Thanks all!

 

Most radios have two power wires. One is an always "hot" circuit so that information stored in memory won't be lost (time and preset stations) and the second power wire is only hot when the key is turned to "on" or "acc" so the radio comes to life when you turn the key on. I suspect you have a problem with the always "hot" circuit. If you hunt the issue down it may correct the pop.

 

I remember those two from wiring, now I know what they do. Could a reversal of those wires during wiring, accidental of course, cause the radio to run but forget?

 

Ummm, yeah, that might do it becasue when you turned the key off the memory side would be unpowered, BUT it would mean the radio would be on all the time and probably run your battery down.

 

Well, when the vehicle goes off, the radio's time light and sound do go out, so if you mean on in that sense, it does go off. Can it be "on" but appear off? It's been in the vehicle for days now and we are still cranking just fine.

If I did indeed wire the radio correctly, what would cause the forgetfulness?

Thank you!

 

There is a contant 12v wire (red), and a accessory 12v wire (yellow) that powers the unit.

When you turn your vehicle off, the constant 12v wire will ensure the radio retains the clock, stations, etc.

It sounds like you have the accessory wire hooked up, but no 12v constant. That is why the radio turns of when you shut the vehicle off.

 

I will pull the unit out and double verify my connections. Thanks for the information guys, stay tuned.

 

Even if the radio was on all the time, but appeared off it would probably take some time to run the battery down. It would be a pretty slow draw.

 

Verified my harness wiring. The harness I wired is after-market so the colors are different. The new harness has red for for battery and yellow for memory, and using my Hayne's radio wiring diagram, I correctly wired red battery to pink battery and yellow memory to red and white acc/run.

So now that I know these are wired correctly, where do I begin to look...?

 

codyy...
If I'm reading that right, you need to reverse the wires. Memory needs constant power, so it should go to battery. Radio power should come off the ign switch.

I may be misunderstanding which color is on which .

But anyway, you just need to verify that the lead connected to the radio memory is still hot when the ign switch is off. And that the lead connected to the radio power goes on and off with the ign switch. Could have a bad connection in a connector or poss a problem with the radio itself. You could prob check the radio memory on the bench with a 9V battery or DC power supply if you have one, just to eliminate that.

 

Car Radio Battery Constant 12v+ Wire: Red/Black
Car Radio Accessory Switched 12v+ Wire: Red/White
Car Radio Ground Wire: Chassis
Car Radio Illumination Wire: Black/Yellow
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: Yellow
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 5 1/4″
Car Audio Front Speakers Location: Dash
Left Front Speaker Positive Wire (+): Dark Green
Left Front Speaker Negative Wire (-): Dark Green/Red
Right Front Speaker Positive Wire (+): Purple
Right Front Speaker Negative Wire (-): Purple/Yellow
Car Audio Rear Speakers Size: 6″ x 9″
Car Audio Rear Speakers Location: Tail Gate
Left Rear Speaker Positive Wire (+): Brown/Yellow
Left Rear Speaker Negative Wire (-): Brown/Light Yellow
Right Rear Speaker Positive Wire (+): Dark Blue/White
Right Rear Speaker Negative Wire (-): Dark Blue/Orange

 

Most of that seems the same as my Hayne's guide, except I've got PK for battery and red/white for acc/run. On my aftermarket harness this means I have pink to red battery and red/white acc/run to yellow memory.

 

Any further ideas? Any way to check if the wires are indeed wrong or..? I hate losing my radio presets!

 

Seems like the constant 12v wire is not there, or...misplaced.

Get some wire and directly wire to a constant 12v source in your fuse panel. Check your radio specs and see what the amp rating is....I think you will want to fuse it into a 15amp fuse location.

Connect this new wire from the RED wire from the radio, to the new fuse location.

 

use a test light or voltmeter to see if and when those two wires in question have power (key off/on). That should determine which wire is always on and keyed on.

 

Repair is now complete! Tested with a multimeter to find out that my constant and switched were reversed. Changed it back, and now I expect proper time and station memory. The "pop" on key-off was eliminated immediately. Great fix guys, thanks for the information.

 

Awwww I said that 8 days ago...lol...but I only get 1/2 the points cause I didn't say the way to fix it...Right Mark?

 

Well, there was a few different opinions but once I tested with the multimeter I was certain!

 

:bad poster:

 

As long as it works Cody

And I dunno WTH Marks sayin...lol

 

Haha...I just like those emicons............