Replacing car stereo but has odd wiring

[Sinbad]

HI All, I am in the process of replacing the stereo in our motorhome and have found an odd bit in the wiring on the black and yellow wires of the current unit, which is shown in the attached photos. The current unit is a Kenwood KDC-BT73DAB unit which was already installed when we bought the van. I don't think that the unit is wired 100% correctly as it doesn't hold anything in it's memory and I am forever resetting the sound preferences. This happens every time the engine is started and also when the habitation supply is switched on (it automatically disconnects when the engine is on). My suspicion is that this odd part is to do with power supply being 'split' between engine or habitation so that it is always available.

Plan is to replace this with a double DIN Android head unit ( Atoto S8 Standard) and to power it from the leisure batteries (2 x 105Ah which are fed by solar) so there is no interruption to it's supply. There will also be a reversing camera fitted and attached to the unit as the van doesn't currently have a camera on the rear.

I would appreciate any advice or guidance on the oddity and also the proposed power feed.

Thanks

 

[Guigsy]

Power efficiency doesn't seem to be the priority of many head units. They often pull significant current when they're just idling. So be careful about it being permanently on, even with solar.

Head units should have two power feeds. One to maintain their clock and settings that's permanently connected. And another that's the ignition feed.

My head unit is wired with a switch on the dash so I can select between cab (ignition switched) and hab (always on) power sources. I assume that switch is connected to the 'ignition power' on the radio and the memory power feed must be wired to the cab battery?

 

[Jev88]

That little black box looks like a suppressor? Old school cars you had to fit one there or near distributor/alternator to stop interference? The other plugs look fairly normal to me and there should be a direct adapter kit from "base van" to "insert head unit manufacturer here" ? It does also sound like they never connected the always on feed to keep memory etc...

 

[Sinbad]

Power efficiency doesn't seem to be the priority of many head units. They often pull significant current when they're just idling. So be careful about it being permanently on, even with solar.

Head units should have two power feeds. One to maintain their clock and settings that's permanently connected. And another that's the ignition feed.

My head unit is wired with a switch on the dash so I can select between cab (ignition switched) and hab (always on) power sources. I assume that switch is connected to the 'ignition power' on the radio and the memory power feed must be wired to the cab battery?

Thanks for the info and having a manual switch sounds like a good idea, will look at including that when I do it.

I have not traced back the wiring fully yet so don't know for certain but through operating it, it appears to go through the power supply unit for all habitation power as if the ignition is off and the hab unit is off the radio does not work. As soon as the hab unit is turned on the radio springs into life by itself.

 

[Sinbad]

That little black box looks like a suppressor? Old school cars you had to fit one there or near distributor/alternator to stop interference? The other plugs look fairly normal to me and there should be a direct adapter kit from "base van" to "insert head unit manufacturer here" ? It does also sound like they never connected the always on feed to keep memory etc...

Thanks, so by the sounds of it, that suppressor should not be an issue. I am really hoping the rest of it is standard but I guess I won't know for sure until I start 'playing'