Constant Power Source for my SC Radio?

[Jayhawkjustice]

I installed an aftermarket radio in my SC over the weekend and worked on programming the settings to my liking. However, when I turned the car off and removed the key, I realized that I lost all power to the radio. Clearly I do not have a constant power source to the radio and I am at a loss as to where to connect the device. Where is the best place to connect to a constant power source that would not require me to remove a bunch of parts?

[89911]

The 911 is one of the simplest cars I have ever wired. The easiest source would be to use one that is already going to the radio. If you don't have a schematic to use, use a voltmeter and check which one is live with the key off. If you don't have constant there, try the cigarette lighter lead. I am not sure, but generally these are always on. If both of these fail, you can easily run a lead to the fuse box and grab an unused fuse for power or even go directly to the battery and use a power source with an inline fuse. The most difficult part is pulling the wire through an available grommet in the wall between the interior and the front trunk.

[87turbo]

Interesting - I installed a new stereo in my 87' 930 over the winter and have the same problem. I have the 'always hot' lead from the factory connector plugged in the right spot on the stereo and it shows hot when the car is off. But I found that on starting the car the voltage drops to about 9.6v on that lead and that seems enough of a drop to reset the stereo. Haven't looked at it in more detail, but was considering just running a new wire.

Eric

[vreference]

Originally Posted by 87turbo

starting the car the voltage drops to about 9.6v on that lead and that seems enough of a drop to reset the stereo.

Ground issue? Seems like a lot of people end up resorting to running a wire up to the battery. Not the slickest way to do an install though.



Unswitched 12v should, litteraly, be the red (Fuse 1) wire per my '87 Wiring diagram. Switched 12v should be Green.

[911pcars]

Voltage drop during cranking is quite normal. AFAIK, only minimal voltage is needed to maintain the presets. They sell cig. lighter adapters to maintain radio presets (using a 9 volt alkaline battery) when the battery is disconnected. Thus, 9 volts does the job.

May I assume the radio is connected not only to its main power source wire but also to the memory function wire (I forget the exact name for it). When the ignition is OFF, main power to the radio is also OFF, but a this secondary circuit provides the power to maintain the radio presets.

If the memory wire is connected, most likely the vehicle source wire for this circuit isn't ON with the ignition OFF or not working at all. Not sure where this source wire comes from. A look at any 911 electrical diagram will reveal it. If not, there's a number of live terminals on the ignition switch as well as a direct connection to a fuse position in the trunk as options. Try to maintain the factory setup for future troubleshooting.

Sherwood