14 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHRadio not turning on
Reported or suspected cause
loose t tap fuse connection
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
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Reported cause · Original poster
The problem was a loose T tap fuse connection from previous installer.
Leading evidence: 'loose t tap fuse connection' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'loose t tap fuse connection' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check accessory power pin' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
Checked the accessory power pin from the harness and no voltage.
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Performed · outcome unconfirmed · Original poster
Checked the fuse on the �fuse tap� wired from the ignition switch (new) and that was fine.
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Performed · outcome unconfirmed · Original poster
Replaced older kenwood which I thought had died as it was not turning on (rear fuse was fine).
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Performed · outcome unconfirmed
I believe the 2003 and 2004 model ONLY used CAN bus to turn on the factory headunit.
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2004 C4S
stock Bose amp
Replaced older kenwood which I thought had died as it was not turning on (rear fuse was fine). Placed with a new unit but it�s not turning on either. Checked the accessory power pin from the harness and no voltage. The main fuses E1, D8 and 9 are all fine. Checked the fuse on the �fuse tap� wired from the ignition switch (new) and that was fine. However I could not measure a voltage from the fuse tap pin either (using the black wire pin on ignition switch as ground). (Yes the ignition was turned on). Weird. So there is no voltage going to the ignition switch for accessories?
May be the stock amp?
Can a bad amp prevent the head unit from turning?
Sorry - missed 2004 model. I believe the 2003 and 2004 model ONLY used CAN bus to turn on the factory headunit. IE - there is NO switched 12v in the harness at the radio.
-Tom
probably why previous owner tapped the accessories wire on the ignition switch.
gonna have to do more troubleshooting. I may not be measuring the voltage correctly at the ignition switch wiring pins.
This is from the CAI store installation pages:
Red
Key-In Accessory
This wire must be run directly to the ignition switch. Remove the heater duct under the driver's side of the dash. This duct section is easily removed, lie on the driver floor and slide the duct toward the left side of the car to disengage the inboard end-then slide it toward the middle of the car to disengage the outboard end where it connects to the short elbow leading to the left corner dash vent. This will allow better visibility and access. If you look at the back side of the ignition switch from under the dash you will find a double jacketed Orange wire. Tap into this Orange wire for accessory. This circuit will show 12 volts whenever the key is turned on and keeps power until the key is removed from the ignition cylinder.
This connection has been lengthened to reach from the radio location to the ignition switch. A 5 amp fuse and holder has been pre-installed for you.
Below: the back side of the ignition switch. Looking up from under the dash.
-Tom
yup that is how it�s set up.
so bought a new meter just in case the old one was malfunctioning. With the new harbor meter I measured from the ignition switch and got the expected voltage reading.. And now�.. it turns on. The heck�. I don�t know. Sounds great and simple mechanism. No more touch screen yay. Yea go figure.
For those with the stock CDR-23 radio:
There is an anomaly with the 996 radio (amp? MOST bus?), that creates "no sound" .
I had it a few weeks ago.
Lock the car with the remote, then unlock it.
That fixes it.
Go figure.
See post #12
https://rennlist.com/forums/996-foru...-no-sound.html
CDR-23 can sometimes go into "Transport Mode" and no sound .. ( radio sound is not needed during Transport for months on a ship or sitting in a Lot ) .....Doing a "Vehicle Hand-over " with PIWIS will take the Radio (and other things) out of Transport Mode to be ready to hand-over to the Customer ...
The problem was a loose T tap fuse connection from previous installer. Redid and all is well. I recommend the radio for its simpler factor and color adjustment.
^ Glad to hear it's resolved!
For future reference,
4A0 905 849B
replaces original early-version BLACK switch for 1999-2003, and
4B0 905 849
replaces original late-version WHITE switch for 2004-2005. There is said to be some version overlap on 2004 cars.
Make sure no wires are loose or touching metal. I had similar issue, thought the radio was bad but all it turned out to be was a speaker wire touching metal.
This is a source reference. Confirm exact model applicability in the original material.
