Modern Radio in old car - wiring?

[Hobby]

My Acclaim doesn't have its original radio (well it does but with no front to it!) as the previous owner fitted a new stereo which tbh doesn't work very well. Main issue is that when you turn off the ignition it switches off and all the presets are wiped, meaning you have to reset them every time you switch it on...

I think that modern car radios are connected to the battery at all times meaning that they don't lose the presets. Is anyone able to confirm this is the case and, even better, have a wiring diagram I could use to wire up a new radio I've ordered so it works without losing all the presets every time I switch off the ignition?

http://www.ebay.co.uk/itm/180852532155?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_2030wt_952

[AlanChatterton]

usually, modern stereo's have 2 positive feeds to them. One if ignition live, which means when you turn the ignition off, the stereo will turn off. The other is a permanent live, ie live all the time, to keep the presets etc.

Most people bodge it, and put the 2 live feeds together to an ignitioned live, which will cause the presets to be wiped.

Hope this helps,

Don't forget, both lives will need a fuse..... and do the permanent live one off a permanent live feed from the fuse box............. not direct to the battery!

[Lord Sorbington]

Most radios made in the last 5 years or so will have a standard ISO connector.  There are hundreds of adaptors available to match the ISO plug on the radio to the car wiring connector.

For an old car you won't find a car specific adaptor and will need an ISO connector for your radio which will plug into the radio but has no connector on the other end, just the wires.  You can then connect the wires onto your existing car wiring. Use proper connectors.........

It's best to run a new permanent live wire, there's often a spare terminal in the fusebox or you can even take it direct from the battery if you can't find anywhere suitable to connect it.  Fit an inline fuse in the new feed and use the correct fuse rating for the radio.

[roddymacp]

The wonders of the Web allowed me to download the manuals and diagrams for a modern radio that I put into the Spit. Yes,it's a second live that keeps the memory. I merely wired in a connector compatible with the one on the radio and everything worked as it should. Even got the connector free of charge from the local radio shop when I only went in to ask his advice.

[Glenn]

Could be wrong but I seem to remember the convention is red for permanent live and yellow for ignition switched live.  But if it's a Sony unit, swap them over.

[Hobby]

Cheers chaps!