760 cr702

[russwinchester]

The latest challenge in my 760 rolling resto, we’re now into details thank goodness. I have the original CR702 stereo installed, I have the code, unfortunately I think the unit is knackered as it displays “code” but it’s not responding to any inputs. I’ve replaced the aerial so that goes up and down as Volvo intended….so does it sound like the head unit is beyond repair? If so, as much as I could update with something more modern, it just feels wrong, so I might post this in the wants section, but if anyone wants rid of a CR702 that is gathering dust, please get in touch 😂
Alternatively if anyone knows a trick to bring my CR702 back to life then please let me know!

[Clan]

Originally Posted by russwinchester

The latest challenge in my 760 rolling resto, we’re now into details thank goodness. I have the original CR702 stereo installed, I have the code, unfortunately I think the unit is knackered as it displays “code” but it’s not responding to any inputs. I’ve replaced the aerial so that goes up and down as Volvo intended….so does it sound like the head unit is beyond repair? If so, as much as I could update with something more modern, it just feels wrong, so I might post this in the wants section, but if anyone wants rid of a CR702 that is gathering dust, please get in touch 😂
Alternatively if anyone knows a trick to bring my CR702 back to life then please let me know!

see if you can find a later CR 906 from late 1990's , a super radio with RDS and a built in 4 channel amplifier and cassette player sockets on back for an external 4 channel amplifier and 6 CD changer . looks period too .

[360beast]

I'd fit a decent aftermarket unit personally, I removed the CR906 from my 940 and fitted a kenwood unit, the difference in sound quality seriously surprised me, turns out the original Volvo speakers are actually quite good.

[Forrest]

Is it that the CR-702 does not respond at all when you press the preset keys to enter the code or does it reject the correct code?

The code is set at the factory through a set of diodes on the PCB which can be decoded manually. There is a recent-ish thread about it here.

https://www.volvoforums.org.uk/showthread.php?t=313230

Some people have reported that the diodes can become unreliable with age causing correct codes to be rejected. I believe this can be fixed by removing all the diodes thus making the code 6666.

If the preset keys are unresponsive then it might be worth opening up the case to see what’s going on inside. It is possible that someone else has been in there before and left a ribbon cable disconnected. Maybe also try some contact cleaner.

I’ve always found the CR-906 quite adequate in the 940. Back in the day I once scored a virtually unused unit for a starting bid of 99p on eBay. They do still come up but tend to be pricey for what they are.

The CT-906 is the equivalent but with a CD player instead of a cassette. They are rare and pricey but are a direct fit onto the OEM cabling.

Blaupunkt now do a retro-styled but fully modern unit - the Bremen SQR 46. I fitted one of these in my Mk2 Scirocco but have resisted the temptation to try one in the Volvo. I have four Volvos and it might get expensive.

[Laird Scooby]

Fitting any modern head unit is going to improve the sound quality, the components in the original radios are now past their best and are deteriorating through age resulting in poorer performance. Also the solder is now 30+ years old and if it was the lead-free solder, is likely to have several dry joints.

Like Luke, i've fitted a modern unit, mine is a JVC (near identical to Kenwood except for the brand) and comes with BT streaming so i can use my phone as a music library, GPS with all 4 speakers giving me instructions and if a phone call comes in, switch to the call using the handsfree microphone tucked up on the A pillar while hearing the caller via the speakers.

Although mine is a modern unit, it doesn't look wildly out of place, this is a similar unit i fitted in my Rover so you can get an idea what it looks like in the Volvo. If i remember, i'll get a pic later of what's actually in my 760 to give you a better idea :



There are other options, my original fit in the Volvo was to use a Rover R960 and 6-disc CD changer, Volvo used the same head unit and changer but with a Volvo designation (CR-505 rings a bell but might be wrong) but again, as previously mentioned, the components are now 25+ years old and the performance has dropped off :



Just a couple of options, the Blaupunkt suggestion is probably the best option as it looks period but is in fact brand new but obviously costs more!

[loki_the_glt]

I've got the CR906 that came out of the Exxon Valdez gathering dust in the loft if you want an OEM unit.

[Laird Scooby]

As promised, a couple of pics of what the modern unit looks like :





Just some food for thought!

[russwinchester]

After taking the CR702 apart and copious amounts of contact cleaner, no joy.

So I've gone down the aftermarket route...I'm in the process of bypassing the amp, I've never known so many different non-ISO colours of speaker wire in my life.

Does anyone know where I can find a wiring diagram for the speaker wires from amp to door speakers for a 1989 760 V6? Otherwise I'm into trial and error...

[Laird Scooby]

Originally Posted by russwinchester

After taking the CR702 apart and copious amounts of contact cleaner, no joy.

So I've gone down the aftermarket route...I'm in the process of bypassing the amp, I've never known so many different non-ISO colours of speaker wire in my life.

Does anyone know where I can find a wiring diagram for the speaker wires from amp to door speakers for a 1989 760 V6? Otherwise I'm into trial and error...

There is a plug'n'play solution Russ, Autoleads make (or at least made) a plug-in patch lead to convert Volvos contorted wiring into ISO connectors. Have a look on fleabay and find one of these :

https://www.ebay.co.uk/itm/384454529673

That should be right for yours. Also as you have the facelift model, you should be able to direct fit the new DIN head unit straight into the dash panel, if not and for some odd reason you still have the 740 style dash you'll need one of these too :

https://www.ebay.co.uk/itm/181337877710

Having rewired my 760 from scratch without a diagram (at the time) due to the PO fitting a £19.99 Sendai CD/radio with bullet crimps, i know what a pig of a job it is. If the plug'n'play route had been an option, i would have taken it!

[russwinchester]

Thanks Dave, but believe it or not I bought the Autoleads ISO connector thinking easy life, however all the leads in the connector to the Volvo harness were in the wrong place! Even the power and earth leads! So I'm going freestyle....

I'll try trial and error with the amp speaker wires, I'll get there in the end.

Yes my dashboard has single DIN, so that's at least one relief