New Car Stereo - Continuous Power???

[Richard10002]

A five minute job is never a five minute job, is it!

I bought the new Bluetooth car stereo unit, (Sony MEXBT3900U), removed the old unit, (Blaupunkt SantaCruz CD31), and all seemed fine. The connectors on the old unit married up to the connectors on the new unit. Wire colours and functions all the same. Switched power red and continuous power yellow connected together to the switched power source wire, on the old, so ends up the same on the new.... But.....

On the old unit, all stored stations and other stuff was retained when I turned the power off at the boat switchboard. On the new unit, all stored stuff is lost. I'm not actually surprised, but am wondering how the old unit managed to save its settings, whereas the new one doesn't. The new Sony retains its settings when turned off at its own off switch, but not when the supply is switched off.

I was actually expecting to find the existing continuous power cable separate from the switched power cable, and was surprised to find them joined and connected to the switch.

Am I going to have to run separate cables the length of the boat, (I'll probably run a 3 core to separate the stereo from other stuff), or is there something secret setting that was set in the Blaupunkt, and needs setting in the Sony, or might it have had a built in rechargeable battery?.

Hope this makes sense!

Help, (although I think I know where this is going ).

Richard

 

[pvb]

The continuous power lead can be fairly thin cable, as it's basically only powering the memory. Just run a single cable back to the battery, but you must put a fuse (say 5A) in the cable as close to the battery connection as possible. The switched power lead can stay where it is.

 

[prv]

Old memory technologies needed a continuous supply of power to keep the data alive. (Actually, even older ones didn't, but I very much doubt anyone built a stereo with cores or drums!). Newer ones don't - take the card used in your digital camera, for example - so there's really no need for a stereo to require power to save the data. It kind of surprises me that one does, but apparently so.

Not much for it except to run a new cable. Or I guess maybe you could wire in a small battery to keep the memory alive? You get some 12v batteries that look like half an AAA; if the current draw is just for the memory then one of these might last a season or more?

My Fusion stereo, being designed for use on boats, does not require such fannying about.

Pete

 

[Richard10002]

.

Not much for it except to run a new cable. Or I guess maybe you could wire in a small battery to keep the memory alive? You get some 12v batteries that look like half an AAA; if the current draw is just for the memory then one of these might last a season or more?

If I got one of these batteries, would I connect the continuous power yellow cable to the positive end, and run a cable from the negative end to the ground/negative of the stereo. If this is how it works, I'm tempted to get something like this from Maplins to hold 8 AA batteries which would give something like 1000mA at 12V?

http://www.maplin.co.uk/aa-size-battery-holders-31427

I'm wondering if it's wrong to have 2 negative wires coming out of the stereo - 1 to the switch, and the other to this new battery pack. I guess electrics sort themselves out in this respect?

Thanks for the help.

Richard

 

[Richard10002]

The continuous power lead can be fairly thin cable, as it's basically only powering the memory. Just run a single cable back to the battery, but you must put a fuse (say 5A) in the cable as close to the battery connection as possible. The switched power lead can stay where it is.

If I was going to run a cable of any kind, I'd probably run a multicore cable to allow for future additions. 8 cores could allow for a couple off negative/ground cables plus 6 positive cables, for example. I think it would be seaside to feed a thicker cable through some of the spaces, than a thin cable.

Thanks for the help.

 

[30boat]

My old Sony required the yellow wire to be directly conneted to the battery in order to maintain the stations .I've just fitted a AEG stereo that won't even work if the yellow wire is disconnected.The problem with the old one is that it flattened two batteries to death before I realised the cause so now I do without memorized stations and connected the yellow wire to the battery switch.

 

[elton]

If I was going to run a cable of any kind, I'd probably run a multicore cable to allow for future additions. 8 cores could allow for a couple off negative/ground cables plus 6 positive cables, for example. I think it would be seaside to feed a thicker cable through some of the spaces, than a thin cable.

Thanks for the help.

The ground cables should be equivalent in capacity to the positives, otherwise you're limited to the maximum capacity of the lesser. In other words, there's no point in running 6 positives and 2 negatives (of the same gauge).

 

[nigelmercier]

Leave it powered up for a few days, it may have gold capacitors as the back-up.

 

[Ruffles]

I used the cable from the battery meters for the permanent connection. You may have similar.

Mine was originally un-fused so added a couple of in-line fuse holders near the battery switch.

 

[pathfinder]

I have a similar set and the permanent 12v also powers the amplifier so a small set of batteries won't do this for you.Best to run separate fused 12vdc supply from battery.

 

[Ric]

General advice - don't buy Sony consumer goods. They are hopelessly complicated to use as they are designed for Japanese minds which are presumably wired differently to ours. Also, doesnt surprise me that Sony has volatile memory - everything I have ever bought by Sony also had volatile memory.

I have a similar set and the permanent 12v also powers the amplifier so a small set of batteries won't do this for you.Best to run separate fused 12vdc supply from battery.

 

[Maine Sail]

I have a similar set and the permanent 12v also powers the amplifier so a small set of batteries won't do this for you.Best to run separate fused 12vdc supply from battery.

On most 12V car stereos (at least since the early 90's), not just Sony, the yellow wire carries the vast majority of the 12V DC load so it serves as not only a memory wire but also your head units power source feed. It is normally a larger gauge wire than the red/ignition wire. This is pretty much the industry standard. The red wire is simply ignition/remote turn on to to turn it on, and it carries very little power. Even the "marine" stereos by Fusion use the yellow lead as system power and red as remote/ignition on...

The standby draw of these stereos can vary but is often around 0.001A - 0.008A (worst one I have measured).. Even at 0.008A the Ah consumption from an entire week is just 1.3Ah's.

The Kenwood Excelon on our boat draws .002A or just 0.34Ah per week..

 

[misterg]

On most 12V car stereos (at least since the early 90's), not just Sony, the yellow wire carries the vast majority of the 12V DC load so it serves as not only a memory wire but also your head units power source feed.

THANK YOU!

I put a Sony CD/MP3 player in our boat a few years ago and couldn't understand why the 'backup' power fuse kept blowing while the player was in use. I thought I must have got the switched / 'backup' supplies mixed up, so I swapped them around, but then (obviously) the radio stations were lost when we shut the batteries off, so that wasn't the case. I thought I was going nuts!

I reluctantly concluded that the 'backup' supply was the main supply, but had never been 100% happy with that conclusion or seen it confirmed - 'till now!

 

[PabloPicasso]

Old memory technologies needed a continuous supply of power to keep the data alive. (Actually, even older ones didn't, but I very much doubt anyone built a stereo with cores or drums!). Newer ones don't - take the card used in your digital camera, for example - so there's really no need for a stereo to require power to save the data. It kind of surprises me that one does, but apparently so.

Not much for it except to run a new cable. Or I guess maybe you could wire in a small battery to keep the memory alive? You get some 12v batteries that look like half an AAA; if the current draw is just for the memory then one of these might last a season or more?

My Fusion stereo, being designed for use on boats, does not require such fannying about.

Pete

Oooooo Fusion stereo oooOOOo. Suits you sir

 

[timmygobang]

Right I'll add this to my job list, it's been annoying me for ages!!

 

[Stemar]

General advice - don't buy Sony consumer goods. They are hopelessly complicated to use as they are designed for Japanese minds which are presumably wired differently to ours. Also, doesnt surprise me that Sony has volatile memory - everything I have ever bought by Sony also had volatile memory.

+1.

Also volatile functioning, in my experience. They seem to last just a little longer than the earlier of warranty expiry or loss of receipt.

 

[dutyhog]

+1.

Also volatile functioning, in my experience. They seem to last just a little longer than the earlier of warranty expiry or loss of receipt.

It seems easy enough to remove the whole car radio from the boat in winter. That should help prolong life, unless the deterioration is due to vibrations and slamming, or big voltage spikes, rather than high humidity, condensation or salt in the air.

I've just installed a Sony car stereo, with LW, and hope it will last more than warranty.

PS the LW is for R4 and its shipping forecasts, when in those places where there is no coastguard reception (quite a few) or mobile signal, and certainly no wi-fi or FM/DAB.

 

[lustyd]

The continuous power lead can be fairly thin cable, as it's basically only powering the memory. Just run a single cable back to the battery, but you must put a fuse (say 5A) in the cable as close to the battery connection as possible. The switched power lead can stay where it is.

Obviously when you say fairly thin cable, you mean one which can take 5 amps at 12V otherwise the fuse is worse than useless

 

[simonfraser]

Send it back to amazon and order a more suitable product

 

[KAL]

My old Sony required the yellow wire to be directly conneted to the battery in order to maintain the stations .I've just fitted a AEG stereo that won't even work if the yellow wire is disconnected.The problem with the old one is that it flattened two batteries to death before I realised the cause so now I do without memorized stations and connected the yellow wire to the battery switch.

+1

Did not want to risk battery run-down so wired my Sony's continuous supply to the switched supply and just do a 'seek' for the station we need when we switch on.