JVC to Sony?

[Simpo Two]

Afternoon all.

This is actually for a boat, but it's a car stereo so hopefully someone will know the answer.

My boat was fitted from new with a JVC KD-R331 CD/radio, and hence has a bunch of wires sticking out of a bulkhead that end in a JVC-shaped plug. 8 are for speakers, plus black and red (power I deduce) and yellow. Don't know at the yellow one is - earth?

Anyway, I hate the JVC unit, and want to replace it with a Sony MDX-C5970R because that's what I happen to have going spare and I like it. Naturally it has a Sony-shaped socket at the back. I have an adaptor cable for it which ends in two ISO plugs.

Can I get a JVC line socket to Sony plug, or do I need to go via ISO, in which case I'd need JVC line socket to ISO plugs?

Help required please

[Simpo Two]

Thanks. At present there's about two feet of mixed wiring emerging from a hole in the wall between saloon and cockpit. It looks like they chopped the ISO sockets off the cable that came with the JVC unit and wired it directly into the boat's electrics with bullet connectors.

I have Sony to ISO male adapter, and I can find JVC to ISO male... is there an ISO female-female adapter to join them that way?

If necessary I can join bare wires with a soldering iron. Speakers are easy to work out but the others I'm not sure of. I could take the Sony cable and chop the ISO sockets off, like they did, but the Sony has extra wires which presents options for mistakes.

Edited by Simpo Two on Monday 12th October 17:49

[Simpo Two]

oilslick said:

I'm not aware of their existence, but you could make one with two female ISO harnesses.

That's a good idea!

oilslick said:

However, it's a rather messy solution. If it were me I'd be looking for a wiring diagram for the JVC connector then chopping it out (probably at the bullet connectors that are already there) and wiring in a proper ISO block. Then if at any point in the future you want to change radios, it's a much simpler job, just plug and play with a new adapter for whichever manufacturer you've bought.

I was reaching the same conclusion - found these: https://www.amazon.co.uk/dp/B07DK5WMFD and also https://www.ebay.co.uk/itm/Car-Stereo-Radio-headun... - not sure which is easiest.

Luckily I still have the installation guide for the Sony. Any idea what the yellow wire on the JVC is?

It's not really a boat issue, just a car stereo issue. I can do it, I just need to close the knowledge gap...

[Simpo Two]

Very helpful, thanks. I can work out which lead is which from the JVC plug, and the Sony installation instructions tell me which lead is which for the Sony (and says Red is the switched 12V).

There are three extra leads in the Sony plug over the JVC which I don't think have anywhere to go. Light blue marked 'ATT', blue/white which is connected via bullet to 'power aerial control', and an orange/white one not mentioned in the instructions, perhaps the illumination dimmer you mentioned. Hopefully it will work without those.

I'd like the Sony to be easily removable so will probably get the bare-ended ISO set, wire that into the boat, then it should be easy from there. Does that make sense?

Edited by Simpo Two on Tuesday 13th October 10:39

[Simpo Two]

jakesmith said:

Buy a cheap multimeter...

Yep, got one

By perusing both the JVC and Sony instructions I've got every lead worked out, and by 'reverse thinking' I can identify the wires in the boat. I considered buying a crimper and bullet connectors but in the end decided to solder in an ISO system. Then if I sell the boat it's easy to retrieve the unit.

I was almost there on my own but PH filled in the missing bits