| Radio power source? [message #322042] |
Sun, 13 August 2017 22:28  |
lw8000
Messages: 201
Registered: July 2012
Location: S.E. Michigan
Karma: 1
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Senior Member |
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Hello all,
I have the original AM/FM/8-track radio and recently we were using it, when I noticed that I can use it when the ignition key is not on. This is actually great as we would like to use it this when parked and engine off. My question is, does the radio draw from the engine or house battery? I've looked over the 12V wiring diagrams that I have, and searched other posts, but I have not been able to confirm one way or the other so far.
Thanks as always!
Chris S. -
77 Kingsley, 3.70 FD, mostly OEM -
S.E. Michigan
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| Re: [GMCnet] Radio power source? [message #322045 is a reply to message #322042] |
Sun, 13 August 2017 22:32  |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
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Senior Member |
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The radio usually runs off the house battery. But on my coach, it runs off
the engine battery, and I think that is original. So, go figure.
Rick "noting the radio fuse in the chassis fuseblock" Denney
On Sun, Aug 13, 2017 at 11:29 PM Chris S. wrote:
> Hello all,
>
> I have the original AM/FM/8-track radio and recently we were using it,
> when I noticed that I can use it when the ignition key is not on. This is
> actually great as we would like to use it this when parked and engine
> off. My question is, does the radio draw from the engine or house battery?
> I've looked over the 12V wiring diagrams that I have, and searched other
> posts, but I have not been able to confirm one way or the other so far.
>
> Thanks as always!
> --
> Chris S. -
> 77 Kingsley, 3.70 FD, mostly OEM -
> S.E. Michigan
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com
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| Re: [GMCnet] Radio power source? [message #322049 is a reply to message #322045] |
Sun, 13 August 2017 23:50 |
<rallymaster
Messages: 361
Registered: May 2014
Karma: 2
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Senior Member |
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Disconnect the house battery and try it again. If it doesn't work, it's
connected to that one.
If it does, it's probably connected to the coach battery, but not through
the ignition switch.
ronC
On Sun, 13 Aug 2017 21:28:18 -0600 Chris S.
writes:
> Hello all,
>
> I have the original AM/FM/8-track radio and recently we were using
> it, when I noticed that I can use it when the ignition key is not
> on. This is
> actually great as we would like to use it this when parked and
> engine off. My question is, does the radio draw from the engine or
> house battery?
> I've looked over the 12V wiring diagrams that I have, and searched
> other posts, but I have not been able to confirm one way or the
> other so far.
>
> Thanks as always!
> --
> Chris S. -
> 77 Kingsley, 3.70 FD, mostly OEM -
> S.E. Michigan
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
Ron & Linda Clark
North Plains, ORYGUN
78 Eleganza II
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| Re: Radio power source? [message #322056 is a reply to message #322042] |
Mon, 14 August 2017 07:40 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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lw8000 wrote on Sun, 13 August 2017 23:28Hello all,
I have the original AM/FM/8-track radio and recently we were using it, when I noticed that I can use it when the ignition key is not on. This is actually great as we would like to use it this when parked and engine off. My question is, does the radio draw from the engine or house battery? I've looked over the 12V wiring diagrams that I have, and searched other posts, but I have not been able to confirm one way or the other so far.
Thanks as always!
Chris,
The wiring diagrams that I have looked at always have the radio on the chassis (main engine) battery. It is not switched with the ignition, but that is where it is and it is(was) on a 10 amp fuse in my coach. The real issue here is that the normal car radios cannot draw enough power to significantly drain that battery in a reasonable time. But even still, when I put in the new radio, and the cell repeater and the CB (now gone) and the two extra DEC mouseholes, I also added an extra fuse block to the space behind the glove compartment to be distribution for a run from the house bank. It has been good.
Are you going to make Elkhart? Even if you can only get there for Saturday and Sunday, it is still very worth your while.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Radio power source? [message #322074 is a reply to message #322042] |
Mon, 14 August 2017 11:19 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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The OEM wiring is: The radio powered by the engine battery and powered all the time no matter what position the ignition key is in. Some people have changed them to the house battery side instead.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Radio power source? [message #322075 is a reply to message #322042] |
Mon, 14 August 2017 11:25 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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My 76 was connected to the chassis battery . I relocated to the house battery. The easiest way to do this is to connect the radio wire to the isolator house battery terminal also connect the cigar lighter when you do it. Don't forget be sure they are fused.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: Radio power source? [message #322240 is a reply to message #322042] |
Thu, 17 August 2017 07:42 |
lw8000
Messages: 201
Registered: July 2012
Location: S.E. Michigan
Karma: 1
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Senior Member |
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Thank you everybody for the information, that helps a ton.
Matt, I like your idea of having an alternate fuse panel up in front that feeds from house battery. Would make it easy to switch over one circuit at a time from one to the other. I might look in to that as we have a house battery hot connection close to there under the dash with a cigarette plug. Unfortunately we cannot make Elkhart this year.
Chris S. -
77 Kingsley, 3.70 FD, mostly OEM -
S.E. Michigan
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| Re: Radio power source? [message #322260 is a reply to message #322240] |
Thu, 17 August 2017 15:50 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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lw8000 wrote on Thu, 17 August 2017 08:42Thank you everybody for the information, that helps a ton.
Matt, I like your idea of having an alternate fuse panel up in front that feeds from house battery. Would make it easy to switch over one circuit at a time from one to the other. I might look in to that as we have a house battery hot connection close to there under the dash with a cigarette plug. Unfortunately we cannot make Elkhart this year.
Chris,
Even if you can't make it to Elkhart (even for a day), be aware of the fact that there is a community of owners that are all in striking range and if any one of them can't assist you with your questions, he can probably point you at some one that can.
The first International we attended at all was the last day of Berrien Springs in 2006 when we were greeted by none other than Emery Stora and I would say we were made to feel like family, but in my case, that might not be great. It was maybe more like long separated old friends. At that time, I had owned the coach (soon to be named Chaumière - say Show Me Air) for about 159 hours.
You should put an international on your list of things to experience.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Radio power source? [message #322276 is a reply to message #322042] |
Thu, 17 August 2017 20:59 |
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RF_Burns
Messages: 2276
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
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Senior Member |
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My experience with radios and engine batteries is that low current draws can discharge a battery in short order. The older 70's era radios used class A audio amplifiers and consumed several amps no matter the volume setting (remember the heat sinks and how toasty warm they got). Consider a 2 amp draw from a radio that was ON from 9am to 9pm = 2amps x 12 hrs = 24AmpHrs, that's 50%+ discharge of a typical cranking battery. Compare that to cranking the engine for 30 seconds at 300amps = 300Amps x 1/120hr = only 2.5AmpHrs
We are a Motorola communications dealer. Older crystal radios consumed about 1/4amp while new microprocessor controlled radios can consume about 1 amp on standby. This is enough to kill a battery over the weekend in the summer or overnight in the winter. So we designed a power-down timer. It detects the vehicle starting and turns ON power to the radio. After the key is turned off, it will keep the radio alive for a period of time (usually 4 hours) then shuts the power OFF. Restarting the engine resets the timer. This keeps the radio ON all day, but will power off by 9pm in most commercial applications, leaving the battery with enough power to start the vehicle the next day.
http://www.gmcmhphotos.com/photos/electrical/p28712-12-volt-accessory-power-down-timer.html
I moved my accessories power to the house battery to prevent draining the engine battery.
Just my experience from 40 years of doing this stuff.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
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