Isolate House Stereo From Start Battery

[danesk]

We are new owners of a 2000 Chinook Concourse - learning alot in a hurry!

One problem remains..the house stereo draws power from both the coach and chassis battery. I had read on this forum that it is possible to isolate the house stereo from the start battery by moving one of the two power wires to the stereo.

Though I have searched on this forum and elsewhere, I cannot find a more detailed description of this rewiring project. Can anyone help with some details? Thanks in advance for your help.

BTW, this forum is a wealth of good information. Thanks to all who make it happen!

Dan

[caconcourse]

We are new owners of a 2000 Chinook Concourse - learning alot in a hurry!

One problem remains..the house stereo draws power from both the coach and chassis battery. I had read on this forum that it is possible to isolate the house stereo from the start battery by moving one of the two power wires to the stereo.

Though I have searched on this forum and elsewhere, I cannot find a more detailed description of this rewiring project. Can anyone help with some details? Thanks in advance for your help.

BTW, this forum is a wealth of good information. Thanks to all who make it happen!

Dan

Welcome. The original stereo (Kenwood) uses a rectangular 16-pin connector that is now pretty much an industry standard for our vintage radios. I believe pin 9 (yellow wire) is the wire for station memory and is wired directly to a battery (generally the truck battery). Pin 2 (red wire) is the 12V ignition input which "allows the radio to turn on" and should be connected to the coach battery. If you cut the yellow wire connection and attach the remaining part from the connector to the red wire, both should be powered by the coach battery.

This is off the top of my head and from memory, so I would do some buzzing out of wires before I did any cutting. There is a fuse for the stereo in the 12V distribution panel (brown box), so I assume the main 12V radio power source is from the coach and appears on that radio red wire.

Here is a link to a picture of the pinouts of the connector: http://pinout.net/pinout-scheme/399/Kenwood%2016%20pin

I've thought about doing this, but truthfully, it never seemed worth the trouble, because it's never been a problem. If you leave your Chinook in deep storage for a long time, I suppose the radio could drain the truck battery, but in general use, it's not a significant drain on the truck battery, and the solar can keep both sets of batteries charged with the two-way Sure Power separator, parked in the driveway or outdoors for long stretches. The built-in truck radio would have a similar draw on the truck battery in storage, so it would be safer to disconnect the truck battery cable if it is really going to be stored a long time with no power.

Clay

[Blue~Go]

I'm bushed from a long day at work and about to make supper, but I can give some details as I have done this. Was almost my first project back in 2014! It's not hard, especially if you know what to look for. I had the benefit of another Chinooker having gone before me (Bob Will). I'll see if I can round up some photos too.

[Blue~Go]

Sorry it took me so long to get back to this. I killed part of my keyboard and it has put a cramp in my mind-to-hand writing ability.

So as background, this is one of the first things I did to my Chinook. So I wasn't overly creative, but mostly followed the example set forth by Bob W (thanks, Bob!). It worked just fine, but just saying I didn't experiment with other methods (no need). I think he has a 2000 Concourse and I have a '99. Mine seemed the same as his.

Here is what he said that I had saved before starting the project. I'll add comments below this.

Hi, I just thought of one other thing that caught me by surprise. When I added my Trimetric monitor I started checking out the amps usage of various things in the coach. When I turned on the stereo, nothing changed on the monitor. But when I pulled the fuse labeled stereo on the DC power distribution panel, it went out. Hmm. Checked batteries, pulled out stereo and started trying to trace wiring with a volt meter testing continuity. Finally read the manual more closely, noting that the red cable we assumed was power, was instead the ignition sensor. The yellow wire is the power. Well, I could find the red at the PDU, but not the yellow End result:

Red = ignition sensor = was at DC box (sensor normally on vehicle ignition switch)
Yellow = power = was in cab on start battery

*** The stereo in my 2000 Concourse's coach had its ignition sensor wired to the DC fuse, but its actual power coming from the Starter Battery.

Now, in a way, it makes sense, as this way the stereo always has power, the way any car stereo expects when the car is turned off. It has a tiny drain for keeping its stations, code protection if its a protected stereo, etc. The ignition wire is normally used to tell the stereo to actually turn on and work. So in this case, they made the cab's DC "store" button take over the ignition function.

However. This means if you camp somewhere for days/weeks on end, running the stereo all the time because you like background music, you are draining your starter battery. If you don't turn the vehicle on during that time, you could find yourself with a depleted battery. Not to mention a long term small load on a starter battery is not a great thing. My stereo seems to have a draw between 1 and 1.5 amps while I'm running it with the speaks where I normally do (not very loud), but the stereo's manual talks about being on its own 15 amp circuit and I did get it as high as nearly 9 amps before the blinking thing was too loud for me to want to continue my test.

It also means the starter battery had 2 drains on it all the time, the car stereo and the coach stereo (and in mine case, my Viper alarm system as well).

I decided I didn't like this, so I changed the wiring so both the yellow power and red ignition sensor wires go to the coach's DC PDU. Strangely, we found that if we connected the yellow and red together, essentially making both wires be on the same fuse, the stereo didn't work, and its panel seemed to flicker in time with the charger/converter's light (on my PD4645 I have the Charge Wizard light blinking at various speeds to show bulk/absorption/float stage). When we moved the virtually no-power ignition wire to another fuse, everything seemed fine, and the stereo has been working for the past week. Of course, there was only the one wire going back to the PDU, so we had to find another (or run a new wire). We ended up using the extra power wire left over from removing the VCP (VHS video cassette player, remember those?)

Note that trying to just reverse the wiring to put the ignition wire on the starter battery and the yellow power on the coach, did not work. Not sure why, maybe grounding issues? Tried various things and then gave up, as having both on the coach worked eventually.

Note also that having the stereo power on the coach means that when the coach "store" button in the cab is turned off, the stereo has no power at all. It kept the station settings when I had store on for a few minutes, but no idea how long it would keep those when staying in store mode. When you turn the store button back on, the stereo will make noises as it goes through its power-up, including what sounds like moving/testing the CD mechanics.

So he basically says it all here. I found the yellow wire behind the coach stereo and wired it to the abandoned VCP (VCR) wire since I had removed that. If I had not had that wire I could have used another one (for example my Chinook came with two yellow wires running up to the overcab (one on each side) that must have been for some sound system option that were not connected at either end).

Here is an excerpt from my notes on my original wiring (coach wiring). I tested each wire and made notes by circuit number and wire color (from the brown box).

8) 20 amp -- 12 gauge black - was VCP/VCR. Now powers one of the stereo wires (the one that used to go to dash). (This one causes radio to go off, and when fuse re-inserted radio does start up cycle but stays off.)

9) 15 amp -- 14 gauge green - stereo. This is the original coach stereo wire, still used for that.

So based on Bob's notes above (because I don't remember specifically except that his notes worked fine for me):

1) Red wire from back of stereo connected to green Chinook wire which ran to brown box (house power). This stayed the same.

2) Yellow wire from stereo ran to cab originally (start battery) in overcab; now connects to black wire that used to power VCR.

So this all happened right "behind" the coach stereo in the overcab.

[danesk]

Thanks Blue-Go and caconcourse for the very thorough, detailed explanations and procedures. This will give me enough knowledge and confidence to proceed.

For a Chinook newbie, this forum has proven to be extremely helpful!

Dan