CR-824 Radio repair and bluetooth integration

crawlvo

I finally found a CR-824 radio thanks to another Ozvolvo member, seems they are hard to come by!
From what I can tell, they only came with some Turbo models from 90-93 ish?
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I've wanted one as it looks way nicer (I think) than the CR-728 in the '93 940GL, which had its own issues. It is plug and play with the big 14-pin connector on the back (rear of CR-728 shown)
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Anyway, this unit was reported as not working. Let's open it up and see...

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Right off the bat I see the drive belt for the tape deck has turned back in to tar - no worries, a fix for another day.

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The unit looks OK inside aside from some electrolytic caps that have leaked. easy fix, right?

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The schmoo has eaten away at the PCB. This has happened next to the stereo amp chip LA4445, which I think just drives the dash tweeters. Craig from the SA club told me he had a unit in with the same fault, makes sense as this is where heat is being produced.

Repair of the board is the same as with your 940 Speedo - scrape and clean off the solder mask, reinforce or replace the traces, and ideally cover with some conformal coat (which I don't have)

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After buttoning it back up, it works a treat! I replaced some other caps and gave it a general service - after 30 odd years solder starts to go grainy and weird.

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Some notes!

Make sure you have the EQ shorting/blanking plug in the right orientation!
The 824 radio has its removal clips easily accessible behind the volume/frequency knobs, as opposed to the "shove screwdrivers through the gaps in the trim" method from the 728 and similar.
Enter the code (6 digits) then press AUT to confirm. If you keep entering the code or hit other buttons (ie on the 728 once you punch in the 4 digit code it will unlock straight away) you will be locked out for 2 HOURS (ignition has to be in KPII or something)

The main reason I got this radio is it can interface with a CD changer - so I should be able to interface with it and inject audio over bluetooth! The 728 has a plug for this as well, but it seems you can't choose the CD stream over the others, it has to be triggered by the changer...
My previous solution was a cheap bluetooth board wired into the EQ jack on the 728 - had heaps of alternator whine. More to come...

Clive740

crawlvo

I like what you’re doing, my radio and EQ were already gone when I bought the car. The previous owner had installed a DAB Kenwood head unit which if I’m honest, I’ve grown to like. But I do like the idea of factory audio that’s updated with modern conveniences. Nice work.

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crawlvo

That kenwood looks pretty sharp I reckon, a good fit for the wood trim

Clive740

crawlvo

Cheers, but I still prefer the factory look with the radio recessed into the OEM fascia. The aftermarket fascia sticks out a bit too much for my liking. But it’s neat enough. It took me ages to find a decent insert for the pocket below the radio. I got this one from the UK.

I’m looking forward to seeing your finished set up. Have you upgraded speakers?

crawlvo

Clive740 The stock angled fascia is a bit odd too when you look at it for too long I reckon.

Yeah, some Focals in the front and kickers in the back. I had to cut some material out of the doors for the fronts 6.5's which part of me regrets a bit. Lots of rattles to chase down with low frequencies!