Wiring behind radio

[Palmerdad]

I pulled out a dead Sony radio from my '76 Eleganza and replaced it with a new one. I ran power and ground from the back house battery since the
interior of the MH was out. However I'm not sure what to do with the wires that were hooked up to the old radio or if a po tapped into something that
needs to be rewired. While we had the old one out a couple of these wires must have touched and blew the Aux battery/radio fuse in the glove box.

Here is a pic of what I'm looking at. The little transformer was in a plastic box that said Sony so it must have been added when the last radio was
installed.

http://www.gmcmhphotos.com/photos/data/500/medium/wires1.jpg

--
-James Palmer, Traverse City, MI
1976 Eleganza

 

[thomas phipps]

Watch the wiring carefully. Do not connect anything to 'grey' wire. It provided the dimming function to the OEM radio display. Your new radio probably
requires 4 ohm speakers, OEM were 8 ohm.
If you do not know the purpose of the OEM wires, or the P.O. add-ons, do not use them. I remove unidentified wires, especially if connected at only
one end. Cover bare wires ends.
I ran a separate power lead for my replacement radio from the house battery. Lets you run the radio without using a key.
The little transformer labelled 'Sony' may be for noise suppression. See if you can find the Sony manual on the Internet and backtrack from the Sony
connector for wire function.
Tom, MS II
--
1975 GMC Avion
KA4CSG

 

[RF_Burns]

The little "transformer" looks to me to be actually a power line choke (it appears to have only 2 connections) with a capacitor to ground. This would
have been in the power line to the radio to filter out alternator whine.

From the chassis wiring diagrams, the OEM wiring to the radio was
- Yellow is battery power from fuse panel
- Gray is dash lights (for dial lighting)
So it appears the radio was wired to run all the time from the factory, manual shut off.

The pink wire was the old radio's main power and the small yellow wire is the memory backup. Since you have run a wire from the house battery for the
radio power, I would cut the large yellow wire at the junction and cap it off with a blue butt connector to prevent shorts. Find the gray
illumination wire and if you new radio has an illumination connection use it, or cap it off as well.

Be aware your coach may have been wired with grounded speakers and your new radio will expect ungrounded speakers. Since it had a newer Sony radio in
it, the PO should have already dealt with this... but I would check to be sure the speakers are not grounded to be safe.
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
Hubler 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

 

[jdlisenby]

The Sony box should be a noise filter. If you are running new wiring, I second Tom's recommendation on cleaning out the PO's added wiring. The red is
your usually switched power ran to your acccessory so the radio is controlled by the key, most in the RV world want it constant so you don't need the
key to turn on the radio. The Yellow is constant 12v to keep station memory and clock etc. , and the black is ground. You can tie the yellow and the
red from the radio to your new 12v +. Here is a link to the standard car audio wiring codes :

http://http://knowledge.sonicelectronix.com/car-audio-and-video/accessories-and-installation/wiring-harness-color-standards/

Also, accepted practice when working on any wiring is to disconnect the negative battery post to prevent arcing and damaging wiring or parts. My first
job was installing car stereos, I learned this one the hard way

--
JD Lisenby- USAF Ret
1978 Royale-455
Electromotive Tec2 FI & ignition

Navarre, FL

 

[jerry burt]

Great reference. Here is the correct URL:
http://knowledge.sonicelectronix.com/car-audio-and-video/accessories-and-installation/wiring-harness-color-standards/

> The Sony box should be a noise filter. If you are running new wiring, I second Tom's recommendation on cleaning out the PO's added wiring. The red
> is your usually switched power ran to your acccessory so the radio is controlled by the key, most in the RV world want it constant so you don't need
> the key to turn on the radio. The Yellow is constant 12v to keep station memory and clock etc. , and the black is ground. You can tie the yellow
> and the red from the radio to your new 12v +. Here is a link to the standard car audio wiring codes :
>
> http://http://knowledge.sonicelectronix.com/car-audio-and-video/accessories-and-installation/wiring-harness-color-standards/
>
> Also, accepted practice when working on any wiring is to disconnect the negative battery post to prevent arcing and damaging wiring or parts. My
> first job was installing car stereos, I learned this one the hard way

--
Patti & Jerry Burt
73 Gmc 26' Canyon Lands -
Photos - http://jburt.smugmug.com/GMC-Motorhome
Lots of upgrades but lots to do to make it ours.
Members: FMCA - GMCMI - GMCWS - Pacific Cruisers - 49ers

 

[jdlisenby]

Thanks! I fixed it
--
JD Lisenby- USAF Ret
1978 Royale-455
Electromotive Tec2 FI & ignition

Navarre, FL