DIS

Hi to all
This issue relates to a 1991 964 Targa with TIP.
The radio quit working a few days ago but the radio had power, judging from the "background light" of the display and the lights in the CD slot. There was just NO DISPLAY and NO SOUND.

I was ready to replace the radio, but then I had trouble determining how to remove the radio. I tried to enter the CODE, but the display did not show anything.
Finally I checked my fuse listing, and found that fuse 38 was the radio fuse. So, for just fun, I pulled the fuse and amazingly the display came on and CODE displayed with the fuse removed.
I put the fuse back, entered the CODE, and my radio is back in operation. Do not know for how long, but.....
One thing I observed was that there was still power to the radio with the fuse removed, and that after shutting the radio and ignition OFF, the little red light (Theft) was still flashing.

So two questions: 1. What was/is the problem with my radio 2. Where does the power for the alarm light come from and what fuse controls that.

Thanks
Don
1991 964 Azure, Targa, TIP, 40K miles.

DIS

Hi

The tip to remove fuse 38 was a great tip. I had the same problem, removed the fuse, put it. back, entered the radio code,
and WOW! Radio came back alive.

Thanks a lot

Don

1991 964 Tip/Targa/Azure/35K miles.

cjoenck

I think the radios all have essentially two power supplies, on switched and the other one always on. The always-on power supply is needed for the radio to retain its memory functions, including the security code. By pulling the fuse, you obviously disconnect the radio and reentering the security code reactivates the radio.

Silvertarga

what some call a hard reset..

cjoenck

Exactly. Believe it or not I just had to reboot / hard reset my fridge, yes my fridge, to get it to cool again. Now that's progress.

rmurphy1969

Removing the factory radio is easy if you have the wire tools with a 90 degree bend at the end. There should be 4 small holes in the radio face, and it takes some jiggling. The tools release a tabs on the side of the radio that hold it into a sheet metal frame. If your radio has a slot instead of small holes on the face, you'll need a different too but they're available online for about $7.

dmaddox

I know an older thread, but this secondary source of power may be my problem.

i have the same behavior…blank, no sound but backlit. When I remove fuse 38, my radio won’t turn on at all, totally dead.

Can anyone shed light on what fuse/source is providing power when 38 is unplugged?

thank you!

-nick

If you pull fuse 38, and turn off the ignition, then you've removed all sources of power.

Fuse 38 is always hot. That's the red wire into the radio for memory. The main power is the thicker red/black (some radios use the memory wire as memory+main power, and the ignition switch as just an on/off input). The red/black goes through the ignition switch and is "on" in key positions 1/2/3.

dmaddox

I see, thank you.

So the OP, turn the ignition on (not necessarily started) pulled 38, put in the code, replaced 38, fixed?

Without 38 in any ignition (I didn’t try starting) my radio has zero power.

With 38 in, it comes on, I hear a light speaker pop and the backlight on, but no sound and the screen is blank.

-nick

My first check would be to make sure that there is +12v on the red/black wire with ignition on. Then check for +12v always on the red wire. Then check continuity on the ground wire. If that is all good, then the radio almost certainly has internal problems.

Sounds like the OP used the fuse to remove all power and reset their radio. Radios can be a little weird when it comes to the main and switched power sources, but the same should be accomplished from just pulling a battery cable.

dmaddox

Thank you @-nick !

In fear of sounding daft, where is the best location for testing for these voltages? I’d assume pulling the radio, however if there is an easier spot, to avoid pulling the radio, that would be awesome.

I guess I’ll have to pull the radio anyway at this rate.

thanks again!

-nick

I would pull the radio. Use the hook/puller tool to make it extra-easy

amomin2321

Mine does something similar to dmaddux. I pulled the fuse and put it back in...Got speaker pop, backlight and code...when I enter 4 digit code I get nothing
Is there something I am doing wrong, for example is there an enter button or something after the 4 digit code? Any help is much appreciated.