Installing The Continental TR7412UB-OR Radio
 

Background: My interest in upgrading the stereo in my 993 began when my Son said that Jax Teller and I must be the only two people on Earth still using a flip-phone. My phone is Bluetooth capable however and I had grown used to using it in my Audi sedan. Then too, the iPhone 6S was about to be introduced, so I decided to look into replacing the factory radio to take full advantage of 21st Century communications and entertainment.

The original owner of my car had the dealer pull the CDR-210 delivered and replace it with a CR-210 radio. An FM-modulated Pioneer CD changer was also dealer-installed giving the car Radio/Tape/CD capability. This meant that I was looking for a full-featured, black matte, retro radio without an optical CD.

At the time I began, there were isolated Rennlist posts describing Kienzle installations. But other options, Continental and VDO were also available. Kienzle in Germany sells all three brands, go here: http://www.kienzle.de/p_cmn_audio.html Product descriptions of each can be viewed and downloaded. Click the "Details" button of the radio of interest, then "pdf" on the resulting page.

I chose the Continental TR7412UB-OR for two reasons; orange illumination and a Worldwide turner that can be set for North American AM/FM frequencies. German companies sell this radio on eBay and Amazon-Germany (amazon.de). An occasional unit may be available from Rennlist members.

Preparation: There are three original factory set-ups for the 993; standard installation, the M490 HiFi option and DSP. My car had the HiFi option in which the factory CR-210 functioned as a head unit with line-level outputs to a Nokia power amplifier located under the passenger seat. There are six speaker level outputs from the Nokia amplifier, full range to both rear speakers, full range to the front mid-range and tweeters, and low frequency outputs from an internal cross-over to the 5 1/2 inch speakers located in the doors. I'm going to describe installation of the Continental radio in my HiFi-optioned car.

If you have the standard CR/CDR 210 installation, you are in luck. The Continental installation is essentially plug and play, a 3/10 on the DIY scale.

Regretfully, none of these three German radios have line-level outputs, which means that a line-out converter (LOC) has to also be installed to convert the radio's speaker level outputs for the Nokia power amplifier if you wish to keep using it. I wired my Continental radio directly to the factory speakers and removed the Nokia. The Nokia amplifier power was advertised as 25 WPC in Porsche factory literature and that's probably a peak-to-peak claim. The advertised power of the Continental is 4 X 41 Watt Max (peak-to-peak) and 4 X 25 Watt RMS, which is a more meaningful value. So the Continental is at least as powerful as the Nokia amplifier.

The following pertains only to a CR/CRD 210 removal and installation of the Continental. My primary goal was to maintain the integrity of the factory radio harnesses in the event that a future owner would like to revert back to the original set-up. That meant no splicing into factory wires.

Several inexpensive items from Harbor Freight made this job much easier; a Nylon Pry Bar Installer Kit (Item 69668) - much better than a cloth-wrapped screwdriver, a Nylon Fish Tape (Item 66505) - for pulling the harness down from the dashboard, and a palm-sized LED flash/flood light (Item 62532) to help see inside the dash through the radio cut-out. Go here: http://www.harborfreight.com/

You can buy a conversion "harness" from a number of on-line vendors, but these appear to actually be "pigtails" that require splicing wires to fabricate a speaker lead harness. Now that the Radio Shack near me has closed, I have no easy access to electronic supplies, but fortunately, I found an alternative. Go here: http://www.nexxia.co.uk/ for the following items:

1 ea. PC2-101-4 Car Radio ISO Extension Cable 2.5m
1 ea. M-50-1 Car Radio ISO Connector Pins, Pack of Ten
1 ea. M-59-1 Female Power ISO Connector Housing

The Extension Cable is long enough to reach from behind the dashboard to under the passenger seat. The Connector Pins and Housing are used to fabricate a short power patch cord.

A cable is much easier to pull from behind the dashboard than an eight-wire speaker output bundle. Tesa Black Fuzzy Fleece Interior Wire Loom Harness Tape is better alternative to 3M friction tape for wrapping the wires. Search here for suppliers: www.amazon.com

The factory Nokia power amp interfaces the speaker leads through a 25-pin pcb connector manufactured by TE Connectivity. The part number needed and description are 825535-1 25 P Messerleiste. Contact TE Connectivity for current sources: Go to http://www.te.com/usa-en/home.html.

Removing the CR/CDR 210 Head Unit

Search Rennlist for the full procedure. Briefly, it involves removing the faceplate, then inserting a key on the right and left front sides to unlock the radio from its galvanized DIN 1 retention frame. Unlock, then slowly pull the radio forward and carefully remove the plugs and antenna from the back of the chassis.

When the radio is completely free, inspect the back of the chassis. It should look like this:

REAR OF CR/CDR 210 RADIO

Attachment 977510

Note the "A," "B" and "C" ISO blocks. The A block is 12 V power, the B block is speaker outputs (unused in HiFi Option/Nokia cars) and the C1 block contains the line out connections used to feed pre-amp signals to the Nokia amplifier. The C2 and C3 blocks were not used in my radio, but may be in yours depending on related accessories.

Here is the back of the Continental chassis:

Attachment 977511

Note that pins A4 and A7 of the factory harness have to be exchanged with each other to install the Continental. The "ignition" and "battery" connections are reversed.

Using the appropriate corresponding Nexxia supplies, a short male to female A block harness can be fabricated. Alternatively, the two leads can be reversed in the factory harness male plug - but the factory set-up will be changed. I fabricated a six-inch patch cord for my installation.

Part 2: Installing The Continental TR7412UB-OR Radio
 

Installing the Continental Radio

1. Fabricate a short A block patch cord using the ISO male plug from the Extension Cable, the female ISO Connector and the Connector Pins obtained from Nexxia. Wires not needed can be removed. Exchange the locations of pin-outs 4 and 7 on the Extension Cable's male plug. Google "remove ISO socket pin" for tips and a "how to." I used a small jeweler's screwdriver inserted along the pin shaft, then rotated it 360 deg. They fell out.

2. Wrap the length of the Nexxia B block Extension Cable with Tesa Harness Tape. Leave the last 12 inches free.

3. Partially disassemble the center console, using a Nylon Pry Bar, as described here: http://www.pcarworkshop.com/index.ph...center_console

4. Pass the Nylon Fish Tape from behind the emergency brake handle forward into the area behind the DIN 1 cutout and galvanized frame for the radio.

5. Tape or otherwise secure the fish tape to the free end of the B block Extension Cable and gently pull back so that the cable passes behind the switch array, past the gearshift and into the area just behind the emergency brake handle. Leave enough length in the dash cut-out so that the B block, A block and antenna can be easily inserted and removed in the future.

6. The Continental radio comes with a pre-installed DIN antenna connector in the rear left bottom of the radio chassis. Pull it straight back for removal. It will not be needed.

The Continental fits into the factory CR/CDR 210 galvanized radio frame remaining in the dash cut-out. If a locking installation is needed, the factory frame will have to be replaced by the frame supplied with the Continental radio and their supplied proprietary keys will be required to unlock it in the future. Also, a brown chassis ground wire is riveted to the bottom right rear corner of the factory frame. That will have to be removed and reinstalled on the Continental frame. I chose to place my Continental radio into the factory frame. It does not rattle and is secure, but unlocked.

7. Where and how to exit the center console is a matter of discussion. It may be possible to run the B block speaker wires in a factory chase or trough found under the carpet and soundproofing on the passenger side. On the other hand, some have advised running the speaker leads under the carpet from the center console to the area under the passenger seat. I could not figure-out an easy way to do either of those without removing the center console or carpet and soundproofing entirely, so I exited the center console on the passenger side at the point that the rear carpet section overlaps the front carpet section.

When Cover #9 is removed as described in the pcarworkshop "Updating the center console" procedure, you will see a medium-sized, bright-plated Phillips screw than secures the console to the car body. Loosen this screw, elevate the console with a Nylon Pry Bar and pass the B block cable under the console at the point the rear carpet overlaps the front carpet. Reassemble the center console and the result looks like this:

Attachment 977514

The cable is hidden by the inboard passenger seat bolster. If there is a better way to do this, please contribute your knowledge. I'm not totally OCD - just mostly - and this solution works for me.

As you can see, the B block cable runs forward to the inside of the seat track then back to exit through a cut-out at the rear of the passenger seat area. I protected the cable from sharp metal edges with plastic wire wrap.

8. The passenger seat has to be removed to pull the Nokia amp and access the 25 pin speaker harness connector. Raise the seat all the way, then backwards and forwards for full access to the bolts. Six ea. 8 X 20 mm socket screws secure the seat to the tracks. Rennlist posts have described these as "butter bolts" and "cheese-head bolts." Carefully - very carefully - remove them with a good 6 mm hex socket and ratchet while pressing downward to keep the hex fully engaged into the bolts, so that you do not strip-out the internal hex. My shop charges $2.00 a minute and replacement bolts are $2.75 each from Pelican. Ask me how I know.

9. Protect the sill from scratching with a towel, then tilt the seat backwards to disconnect the power cable to the switches. Fold the seat back forward, then reach in and clean and jerk the seat up and out of the car with your arms fully extended.

Connecting the Speaker Wires to the Factory Harness

1. Disconnect the 25-pin and DIN connections to the Nokia amplifier and remove the four Phillips-head screws securing it to the floor plan. Replace the screws in their locations for future use. Note the 25-pin plug in the following illustration. That is the Messerleiste plug.

Attachment 977515

2. Modify the 25-pin TE Connectivity 825535-1 25 P Messerleiste plug by snipping-off pins 1 through 13 and shortening printed circuit board (pcb) pins 14 - 25. The short pins remaining will be used to connect the speaker leads from the Continental radio.

3. Solder the speaker wires from the Continental radio cable harness to pins 18 - 21 on the pcb side of the Messerleiste plug in the following order - refer to the Nokia amp diagram above for pin numbers and speaker terminations:

Conti Harness Wire Color/Channel/Messerleiste Plug Pin #
Green/LR +/18
Green-Black/LR -/19
Purple/RR +/20
Purple-Black/RR -/21

Pins 14 - 17 are low frequency outputs into the speaker harness from the Nokia amplifier internal crossover. Pins 22 - 25 are full range outputs from the Nokia amplifier. These pin connections lead to the right front and left front speakers located in the doors.

If you are not wiring crossovers, you can connect the door speakers in parallel so that all three on a side will be in the circuit. Or you can connect the corresponding speaker outputs to the full range pins as follows:

Gray/RF - (full)/22
Gray-Black/RF + (full)/23
White/LF - (full)/24
White-Black/LF + (full)/25
Not Used/RF + (low)/14
Not Used/RF - (low)/15
Not Used/LF - (low)/16
Not Used/LF + (low)/17

When wired as described, the low frequency, 5 1/2 inch speakers are out of the circuit and will not play. I initially wired my speakers in this configuration and did not like the sound, so I placed external crossovers into the right front and left front circuits.

Although my factory speakers are good, I plan to upgrade them next Summer. Focal European specification speakers appear to be plug and play replacements, so I wired the front channels with two-way Focal XO13-VR crossovers; go here: http://tinyurl.com/qerven2

Conti Harness Wire Color/Channel In/Output/Messerleiste Plug Pin #
Gray/RF +/W + (woofer)/14
Gray-Black/RF -/W - (woofer)/15
T - (tweeter)/22
T + (tweeter)/23

White-Black/LF -/W - (woofer)/16
White/LF +/W + (woofer)/17
T - (tweeter)/24
T + (tweeter)/25

Do you have pics of the Continental radio installed? Willing to state how much this unit cost or if you want you can PM me the info.

Thanks and great write-up!

Andy

Great detailed write-up, here is mine installed...
You can buy them direct from www.amazon.de at around 105 EUR + 30 EUR shipping to the US (about $155 or so).

Thanks Jansan946 for doing all this research an creating this DIY. It is a great help for people like me who wanted to do the same as you did. I hope to start the install of my Continental in a couple of weeks after receipt of the last bits and pieces I need from your write-up. This is another fine example of people helping others on this forum.

Good write up - thanks.

SiriusXM?
 

Wonderful write up and great looking radio. Can a SiriusXM satellite radio be added to this setuP?

I just ordered the same radio and your install instructions will come in handy. Thank you.

Gaspasser!,

The SiriusXM option in my Audi is hard wired and I see no accessory plug or port on the back of the Continental radio for that, so I doubt it. IIRC, the first SiriusXM unit I had was FM-modulated and if those are still available, that solution might work for you.

I Googled it, go here: http://tinyurl.com/peassu2

Nice job on the write up and many thanks.

So for a standard, non-hifi, non-dsm install, do I need to get the three items from the UK?
{1 ea. PC2-101-4 Car Radio ISO Extension Cable 2.5m
1 ea. M-50-1 Car Radio ISO Connector Pins, Pack of Ten
1 ea. M-59-1 Female Power ISO Connector Housing}

Also won't have to deal with removal of the center console for standard install?

Looking at getting rid of my current multi colored Alpine.

It should be a plug and play, 5 minute job depending on what was done to the factory harness, frame, and alarm wire when the Alpine was installed.

It seriously took < 5 minutes for me on my MB with similar ISO connectors. I would try to just unplug the alpine, then plug in the new one.

I'm working to install the disc version of this, the CDD7418UB-OR. Mine doesn't look like it's going to sit flush in the 964 if I want the facial on there too. Did you have to force the facia in or did it just slide right in?

Thanks!

https://cimg0.ibsrv.net/gimg/rennlis...b291bc3ca.jpeg

It sits flush in the 993 without any issue.

By facial, do you mean the black plastic frame surround than snaps into place over the front of the radio chassis? Try placing it into the dash without the radio and see if it seats fully flush as in deekay911's 993 photo in post #4 above. If it won't go, then the 964 opening may be slightly smaller than the 993. If it does go, the radio may not be seating fully into the DIN 1 frame because harness wiring or the antenna lead is obstructing it.

What are the outside dimensions of your frame's height and width? The non-CD frame dimensions are 2 5/16" H X 7 7/16" W.

Thanks for the quick feedback!

Yes, I meant fascia, not facial. :) I'll check the dimensions tonight, but even without the radio itself it doesn't quite fit. If the non-CD is smaller I'll have to decide how much the aesthetics bother me and if I'd buy that model. It's kind of a bummer, like you all, I spent a lot of time choosing a model that would look relatively stock and got this unit directly from Germany.