OE Radio help.

[Ashc]

My last 740 had the same issue with two outputs on the cr 702. I took the top off it and found a couple of dry joints, which I re-soldered. This fixed the problem.

[swedish brick]

Originally Posted by Laird Scooby

Just a radical suggestion here - have you checked to make sure the speakers actually exist and if so, are intact? It's not unknown for a 30 year old car to have the voive coil but no cone left on the speakers!

The speaker grilles will either unscrw (screw in each corner) or if it's the later one, just pull off with long pegs holding it in.
Before you get too deep into whether you have an extra amp or not, check your speakers!

As for the CR-702 amp/no-amp debate, out of the three 740GLEs i've had, 1 x 87, 2 x88, the first (87) had the CR-702 plus amp, second had the CR-702 but no amp that i could see and the third had a dead CR-702 with amp. I suspect it was an option and the unit with the internal amp wasn't as powerful.
Even the external amp wasn't that powerful, if memory serves from when i checked mine, 25W RMS per channel split between the front and rear speakers for that channel.

If you have a look at this, it's one option from this seller on ebay :

https://www.ebay.co.uk/itm/Volvo-740...X/162552385453

Look at "Sellers other items" if that one doesn't take your fancy and enter 740 in the ebay search bar, it'll show you the various options they do for the 740 which are all plug'n'play and come with a face-plate adaptor, patch leads to bypass the amps etc.

I’ll check the speakers tomorrow. Worth doing regardless I suppose!

I’ve got a known good modern aftermarket CD player radio in the loft, so I’ll dig it out tomorrow and see if it’ll plug in in place of the Volvo unit. At least then it’ll prove or disprove the rest of the system.

I’ve seen those replacement head units on eBay. I’m sure they’re good and all but I just don’t think I can bring myself to fit something that looks like that in an old car! It’d bug me more than not having a working radio!

Would any of the old non oe radios from the likes of blaupunkt etc etc work in this? Or would they have the same problem?

[Laird Scooby]

Originally Posted by swedish brick

I’ll check the speakers tomorrow. Worth doing regardless I suppose!

I’ve got a known good modern aftermarket CD player radio in the loft, so I’ll dig it out tomorrow and see if it’ll plug in in place of the Volvo unit. At least then it’ll prove or disprove the rest of the system.

I’ve seen those replacement head units on eBay. I’m sure they’re good and all but I just don’t think I can bring myself to fit something that looks like that in an old car! It’d bug me more than not having a working radio!

Would any of the old non oe radios from the likes of blaupunkt etc etc work in this? Or would they have the same problem?

Physically your CD/radio will fit with a hole round the edge (you can buy the facia plates separately from that ebay supplier) but it won't plug in electrically unless it was designed for a Volvo. That's why that seller has the patch leads included.

These are the other options for a 740 from them :

https://www.ebay.co.uk/sch/m.html?_o...o+740&_sacat=0

They sell things like the facia plates, patch leads etc separately so you could buy the patch leads and facia plate and a head unit with standard ISO connector plugs.

Howver, be careful with the likes of Blaupunkt, many of these were destined originally for BMW, Mercedes and similar and were deliberately wired with reversed memory and switched +ve connections so simply plugging them in to the standard ISO harness would see them not working correctly.

This was so their original customers had to go back to the dealer for audio upgrades, exactly what Volvo did except Volvo took it to extremes!

You can also buy DIN-ISO patch leads with swappable memory and switched +ve leads to overcome this, i've actually got one but intend using it to enable me to break out on the audio side without damaging the original loom in the car it's going into.

It's not impossible, just needs a bit of checking to make sure you get the right bits to work with what you've got.

[MiniNinjaRob]

I bought a more modern stereo for my 940 as the standard one was rubbish even with new driver units. Mine was the very top of the range one in the last 940’s but it still had so little power it distorted at anything approaching a medium level volume - not great for listening when on the motorway.
I did try to get one with as few flashy lights on as possible which helped.
Sounds great now!
All I bought was a fascia panel (less than £10 eBay), an ISO lead (about £5) and the new stereo itself. All plugged in with no soldering or cutting required. Easy!
I think I could do a swap in 10mins now.

[swedish brick]

Right!

So there’s no point digging out the CD player from the loft then as it won’t plug in to the cars wiring harness. I didn’t intend to fit it permanently as it’s a modern unit - and thus is too ugly to fit in my old dashboard!

I think the only option is to stick to oe parts? But how do you know if any of it works?
I could go on eBay and buy new speakers - presumably any that physically fit will be ok?
A Volvo head unit - completely unknown 30+ years old and probably won’t come with a code.
Then comes the issue of the amp! - again, 30+ years old and completely unknown if it’s any good or not or even if I need it or not!

I’m half tempted to forget about this and just fit everything back in so it looks good but will never work!
It doesn’t help that I know nothing about radios or ice installation! I’ve never bothered with it beyond standard fitment!

[Laird Scooby]

Originally Posted by swedish brick

Right!

So there’s no point digging out the CD player from the loft then as it won’t plug in to the cars wiring harness. I didn’t intend to fit it permanently as it’s a modern unit - and thus is too ugly to fit in my old dashboard!

I think the only option is to stick to oe parts? But how do you know if any of it works?
I could go on eBay and buy new speakers - presumably any that physically fit will be ok?
A Volvo head unit - completely unknown 30+ years old and probably won’t come with a code.
Then comes the issue of the amp! - again, 30+ years old and completely unknown if it’s any good or not or even if I need it or not!

I’m half tempted to forget about this and just fit everything back in so it looks good but will never work!
It doesn’t help that I know nothing about radios or ice installation! I’ve never bothered with it beyond standard fitment!

https://www.volvoforums.org.uk/showt...45#post2564145

Post #45 on that thread - he has a CR-906 with code from a car he's breaking. Almost certainly got the amp as well if you can't find yours. I'm not sure on the connections, whether they'll be compatible but would think so. I'm not even sure the 906 needs an amp but as he's got the car there he can look for you.

As for speakers, 13cm (5.25") speakers fit straight in. Because of the spacing of the pegs on the push-fit grilles, adaptor plates are sometimes a good idea although you can get round that.

https://www.ebay.co.uk/itm/VOLVO-740...5/290388292676

For the sake of a tenner, life is much easier though!

[swedish brick]

Just been out to the car and made a discovery! Not a particularly useful one but...
My car only has front speakers? The two rear door ones are just vinyl door trim material under the speaker grills. The two front speakers look very good though, there’s no obvious damage to them.

The wiring colours on the radio multi plug are:
1 - red + white
2 - grey + red
3 - black
4 - black
5 - unused
6 - yellow + white
7 - unused
8 - blue
9 - green
10 - black (larger diameter wire)
11 - yellow + black
12 - red
13 - unused
14 - unused

Wiring colours on car loom side of multiplug are:
1 - blue + white
2 - grey + red
3 - white
4 - purple
5 - unused
6 - yellow + white (goes to unused connector)
7 - pink (loop to 11)
8 - grey
9 - green
10 - black ( large diameter wire)
11 - pink (loop to 7)
12 - red
13 - unused
14 - unused


I’ve compared this to the Haynes manual for 84 - 88 wiring drawings and it doesn’t match! The colours of the wires are wrong!

[swedish brick]

One other question!

Since my rear speakers seem to have never been there can I simply cut out the vinyl blanks under the unused speaker grille and fit new speakers.
Is the wiring for rear speakers already in the doors? So I can just plug in and go?

[Laird Scooby]

Originally Posted by swedish brick

One other question!

Since my rear speakers seem to have never been there can I simply cut out the vinyl blanks under the unused speaker grille and fit new speakers.
Is the wiring for rear speakers already in the doors? So I can just plug in and go?

Don't know if you'll have the speaker wiring in your rear doors, best way to find out is pop the door card off. Found two wiring diagrams for 1988 and 89 respectively, both have radio diagrams on pg13 (by Doc Viewer page) but neither seem to bear any resemblance to your colour codes. Can't say i'm surprised to be honest but you may be able to make some sense by cross-referencing the pin numbers in the plugs :

http://360.haubits.net/VolvoRacing.s..._740__1988.pdf

http://360.haubits.net/VolvoRacing.s..._740__1989.pdf

The other thing is they're both for the USA models which might add to the confusion! Could give you an idea of what to look for though.

I think if you're going to try and get the rear speakers working, the first thing to do is find out if you have an amplifier or not. If not then you'll likley need a different patch lead (ISO > Volvo) which that seller i linked to earlier should be able to help with. If you have the wiring for the rear speakers then life is easier, add the patch lead, speakers, radio/head unit and jobs a good'un!

In theory at least! Experience with Volvos has taught me things are never as simple as they seem or should be!

[bob12]

Originally Posted by swedish brick

Just been out to the car and made a discovery! Not a particularly useful one but...
My car only has front speakers? The two rear door ones are just vinyl door trim material under the speaker grills. The two front speakers look very good though, there’s no obvious damage to them.

The wiring colours on the radio multi plug are:
1 - red + white
2 - grey + red
3 - black
4 - black
5 - unused
6 - yellow + white
7 - unused
8 - blue
9 - green
10 - black (larger diameter wire)
11 - yellow + black
12 - red
13 - unused
14 - unused

Wiring colours on car loom side of multiplug are:
1 - blue + white
2 - grey + red
3 - white
4 - purple
5 - unused
6 - yellow + white (goes to unused connector)
7 - pink (loop to 11)
8 - grey
9 - green
10 - black ( large diameter wire)
11 - pink (loop to 7)
12 - red
13 - unused
14 - unused


I’ve compared this to the Haynes manual for 84 - 88 wiring drawings and it doesn’t match! The colours of the wires are wrong!

Agreed nothing in Hayes of that colour set-up.

I have found in my files one piece of paper in my hand writing with those pin/colours (more or less) on it with the words 'original connector'. Unfortunately, I have not got any idea what radio it is referring to (although the choice is limited to three different models) ... it would need me to go a rummaging through boxes in the garage!! Hopefully I may be able to do this shortly and I will get back to you when done.

I also guess that's why there is no amp if you only have 2 speakers as the CR-702 has enough 'limited power' to drive two. As Dave said above if you have wires going into the rear door and if you take the door card off you may well find the loom speaker wires.

Bob