Stock radio stays on when ignition is off

[brettdn]

I have a 1998 C1500 with a radio that stays on when the ignition is off and the key is out. This has caused my battery to drain within a few days of not driving the truck. Luckily removing the radio fuse fixes it however every time that I start the truck the radio clock is reset and I lose all of my memory for the stations.

Does anyone know where to start for diagnosing and fixing this issue?

 

[Eveready]

I have a 1998 C1500 with a radio that stays on when the ignition is off and the key is out. This has caused my battery to drain within a few days of not driving the truck. Luckily removing the radio fuse fixes it however every time that I start the truck the radio clock is reset and I lose all of my memory for the stations.

Does anyone know where to start for diagnosing and fixing this issue?

My guess is that your radio was wired into the cigarette lighter circuit by a previous owner. That circuit is energized on an OBS even when the key is off, at least it is that way on a '93 which is what i have . I expect someone wanted to run the radio while the key was off and this was an easy solution. All you would need to do is wire the radio to its original switched circuit and the problem is gone.

 

[brettdn]

My guess is that your radio was wired into the cigarette lighter circuit by a previous owner. That circuit is energized on an OBS even when the key is off, at least it is that way on a '93 which is what i have . I expect someone wanted to run the radio while the key was off and this was an easy solution. All you would need to do is wire the radio to its original switched circuit and the problem is gone.

That makes a lot more sense because the truck was previously a public works truck for the town I live in and they run CB radio 24/7 through the cigarette lighter. I'll have a better look at it this weekend

 

[Eveready]

That makes a lot more sense because the truck was previously a public works truck for the town I live in and they run CB radio 24/7 through the cigarette lighter. I'll have a better look at it this weekend

Aha ! That makes sense then. Please let us know what you come up with. I expect you will be able to move one wire to a switched circuit and done.

 

[someotherguy]

After checking the wiring, if things appear normal, then you may find that the radio is simply defective. The same thing happened to me on my old '96 and it was bone stock original.

Richard

 

[Eveready]

After checking the wiring, if things appear normal, then you may find that the radio is simply defective. The same thing happened to me on my old '96 and it was bone stock original.

Richard

While I don't doubt you, I wonder how that could happen if the radio is on a switched circuit? The OP stated that his problem was the radio staying on when the ignition switch was off causing the battery to run down. "Bone stock" would have the radio off when the ignition switch is off unless radio on an always powered line was an option.

 

[someotherguy]

Just like an aftermarket unit, the stereo has a constant power line (for retaining station memory and other settings), and a switched line. Apparently something inside the stock unit can sometimes go bad and power itself (or at least partially powered) full time. The symptom my 1996 displayed when I first got it was the clock display on the head unit never turned off, and when I removed the radio to check it out the case was hot.

When I put an aftermarket unit in, wired correctly to the constant and switched lines, it operated as expected. Also, none of the other accessories in the truck retained power with the key off so all the suspicion points to the original head unit.

Richard

 

[brettdn]

I'd like to clarify my post a little better for people to have a better understanding of my issue. When I turn the ignition to the off position the radio stops operating and just displays the clock. When the key is switched on then the radio operates like normal. I had a look at the wiring and everything seems to be wired like normal. I even did a parasitic draw test and when the "radio batt" fuse is inserted it draws 28 milliamps and when the fuse is removed there is zero draw.

 

[Eveready]

Just like an aftermarket unit, the stereo has a constant power line (for retaining station memory and other settings), and a switched line. Apparently something inside the stock unit can sometimes go bad and power itself (or at least partially powered) full time. The symptom my 1996 displayed when I first got it was the clock display on the head unit never turned off, and when I removed the radio to check it out the case was hot.

When I put an aftermarket unit in, wired correctly to the constant and switched lines, it operated as expected. Also, none of the other accessories in the truck retained power with the key off so all the suspicion points to the original head unit.

Richard

Now I understand. Probably a switching circuit stays hot as you say. Those old stock head units are not the best anyway. I guess it boils down to whether the stock in dash appearance is important to you or not. Like most, I installed an aftermarket unit and really enjoy the Mp3 and Bluetooth phone capability. That is most likely the easiest solution to this problem.

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[joep88cheyenne]

+1 This way you know where everything is run, and connected. On my 97 Tahoe it seems like either the cassette or CD could play with key off. Was at a restaurant with the po and his daughter, the kids were in theTahoe and listening to music from head unit while we were talking.