Date: Tue, 1 Sep 2015 20:31:45 +0000
Reply-To: Jim Felder <jim.felder@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jim Felder <jim.felder@GMAIL.COM>
Subject: Re: Voltage leak found
In-Reply-To: <BE36E9EF-C455-40D6-8BEB-91ECD5BF02F1@shaw.ca>
Content-Type: text/plain; charset=UTF-8
OK I will try that next.
Jim
On Tue, Sep 1, 2015 at 3:28 PM Alistair Bell <albell@shaw.ca> wrote:
> This subject is becoming a perennial favourite in the list. I measured the
> current draw of my stereo head unit. It was something like 130mA turned
> off, but face plate on. And only 30 or so mA turned off with the face plate
> off. Faceplate off current draw was low enough to for me to accept, I take
> the face plate off if not driving the van for a few days.
>
> Alistair
>
>
>
> > On Sep 1, 2015, at 10:33 AM, Rob <vwrobb@GMAIL.COM> wrote:
> >
> > How do you measure the draw?
> >
> > Rob
> > vwrobb@gmail.com
> >> On Sep 1, 2015 9:39 AM, "Larry Alofs" <lalofs@gmail.com> wrote:
> >>
> >> A lot of the speculation and contradictory "understanding" can be
> cleared
> >> up for any given radio by actually measuring the current draw thru the
> >> wires with the radio in various modes, on, off, high volume, low volume,
> >> etc.
> >>
> >> Larry A.
> >>
> >>
> >> On Tue, Sep 1, 2015 at 11:16 AM, Rocket J Squirrel <
> >> camping.elliott@gmail.com> wrote:
> >>
> >>> This page also seems to indicate that the fatter wire (the constant-on
> >>> wire) is the main source of power for the radio, and the skinnier wire
> >>> (switched) is only used to wake the radio up.
> >>>
> >>> <
> >>
> http://avic411.com/index.php?/topic/36319-which-wire-is-the-power-source-yellow-or-red/
> >>>
> >>> "Without a doubt B+ (the yellow wire) is the main current carrying
> wire,
> >>> but this is only up to a point, as you have seen due to the radio fuse
> >>> not being more than about 10A typically on vehicles. Acc/ignition is
> >>> just a turn-on signal. While it can be used at a lower current
> >>> application, it is not typically meant for higher loads."
> >>>
> >>> --
> >>> Jack "Rocket j Squirrel" Elliott
> >>> 1984 Westfalia, auto trans,
> >>> Bend, Ore.
> >>>
> >>>> On 09/01/2015 07:57 AM, Jon VO wrote:
> >>>>
> >>>> Well, my understanding is a bit different; the ignition switch
> controls
> >>>> /switched/ power to the stereo, and is the source of the amplifier &
> >>>> control power which is usually multiple amps for a high-powered
> stereo.
> >>>> The other continuous power lead is supposed to draw only a few
> milliamps
> >>>> to keep the memory charged and for control functions, and is powered
> all
> >>>> the time. At least that is the way the stereos worked when the Vanagon
> >>>> was current. If you want to reduce the current through the ignition
> >>>> switch, you would need to add a relay, and I believe some newer
> vehicles
> >>>> already do this.
> >>>> Jon
> >>>>
> >>>>> On 9/1/2015 8:45 AM, Rocket J Squirrel wrote:
> >>>>>
> >>>>> The keying wire itself draws little current, it just provides a
> signal
> >>>>> voltage to the unit to put it to sleep or wake it up. The designers
> >>>>> assume that you don't want to draw a bunch of amperes through your
> >>>>> ignition circuit, so it's the the always-on wire that is the main
> >> source
> >>>>> of power for the unit.
> >>>>>
> >>>>> How much current the unit itself draws from its always-on wire when
> >>>>> asleep (standby) is a matter of design. But the key wire is not a
> >>>>> significant current-drawer.
> >>>>>
> >>>>> What I'm saying is that you can put the unit into standby with the
> key
> >>>>> wire and it can still be drawing hundreds of milliamperes through its
> >>>>> always-on wire. That's the one you have to watch out for.
> >>>>>
> >>>>> --
> >>>>> Jack "Rocket j Squirrel" Elliott
> >>>>> 1984 Westfalia, auto trans,
> >>>>> Bend, Ore.
> >>>>>
> >>>>>> On 09/01/2015 07:30 AM, Jim Felder wrote:
> >>>>>>
> >>>>>> I remember when you went through all that, about the same time I
> >> bought
> >>>>>> my radio. So, using the keyed hot wire will draw very little or no
> >>>>>> current? I like the idea from a previous post that I could install a
> >>>>>> switch to connect it to either circuit, aways hot and switched hot.
> >>>>>>
> >>>>>> Jim
> >>>>>>
> >>>>>> On Tue, Sep 1, 2015 at 9:26 AM Rocket J Squirrel
> >>>>>> <camping.elliott@gmail.com <mailto:camping.elliott@gmail.com>>
> wrote:
> >>>>>>
> >>>>>> Many car stereos/radios don't really turn off. They mute and the
> >>>>>> front
> >>>>>> panel goes dark, the power amp sections shut down, and the
> >>>>>> controls go
> >>>>>> to sleep, but they are still partially on and drawing current. I
> >>>>>> guess
> >>>>>> the manufacturers assume that you drive your car frequently.
> >>>>>>
> >>>>>> The current draw is through the main power wire, the other wire,
> >>>>>> frequently connected to the ignition switch, doesn't draw much
> >>>>>> current
> >>>>>> at all -- it is used to signal the unit to wake up.
> >>>>>>
> >>>>>> I had to search high and low to find a unit that actually powers
> >>>>>> off --
> >>>>>> not only from the front panel power button, but from the remote,
> >>>>>> too. So
> >>>>>> I could turn off the music when I get into bed rather than have
> >>>>>> to lean
> >>>>>> up to the dash to shut things down.
> >>>>>>
> >>>>>> --
> >>>>>> Jack "Rocket j Squirrel" Elliott
> >>>>>> 1984 Westfalia, auto trans,
> >>>>>> Bend, Ore.
> >>>>>>
> >>>>>>> On 09/01/2015 06:08 AM, Jim Felder wrote:
> >>>>>>> About a month ago I wrote about having installed two pairs of
> >> USB
> >>>>>> ports and
> >>>>>>> an LED voltage display in my Vanagon. The round double outlet
> >> on
> >>>>>> the dash
> >>>>>>> took the place of my factory Eberspacher heater knob and the
> >>>>>>> outlet-and-voltmeter combination set neatly into what was the
> >>>>>> rear ashtray.
> >>>>>>>
> >>>>>>> That's when I noticed a drop in voltage that would flatten the
> >>>>>> battery
> >>>>>>> after a couple of days of being parked. Long story made very
> >>>>>> short, I
> >>>>>>> discovered that it was my radio in standby mode that was
> >>>>>> draining the
> >>>>>>> battery. I pulled the fuse to the radio on Saturday and this
> >>>>>> morning the
> >>>>>>> voltage is showing 12.9, exactly where it was when I pulled
> >>>>>> the fuse.
> >>>>>>>
> >>>>>>> The reason that this was unknown to me all this time is that
> >>>>>> coincident
> >>>>>>> with the addition of the USB ports the Vanagon was, except for
> >>>>>> use of my
> >>>>>>> wife's Prius, my daily driver had been the Vanagon. When I got
> >> a
> >>>>>> TDI Jetta
> >>>>>>> the Vanagon started sitting for days or a week at a time, and
> >>>>>> that's when
> >>>>>>> the problem showed up.
> >>>>>>>
> >>>>>>> I could wire the radio to the switched 12v circuit that no
> >> doubt
> >>>>>> came with
> >>>>>>> it, but then I would have to have the key on to listen to
> >>>>>> music while
> >>>>>>> camping. Is anyone using a switch on the circuit, and if so how
> >>>>>> was it done
> >>>>>>> and how does it work out for you?
> >>>>>>>
> >>>>>>> Jim
> >>
>
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