GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Two newb questions
Two newb questions [message #321222] Fri, 28 July 2017 20:39 Go to next message
gibsongo is currently offline  gibsongo   Canada
Messages: 116
Registered: October 2012
Location: Montreal West, Quebec, Ca...
Karma: 0
Senior Member
Hello all,

The Moneypit runs - finally. I put about 500 miles on it last week and all the mechanicals seem to be running well. Elkhart here I come!!!

Now its time to have a bit of a go at the interior. The driver and passenger ceiling lights aren't working, and I thought this would be a quick fix - the bulbs in each are blown. Of course the bulbs are a bit strange - not sure I've anything similar at the local parts store. But just to make sure the there weren't any further problems, I measured voltage at the bulb sockets. Yep - there's current......but my VOM reads 18.5 volts. I unplugged shore power, same thing - 18.5 volts. How do you get 18.5 volts from 2 6-volt golf cart batteries?

Second question: I put a Sony double DIN radio in - 55 watts of power per channel for 4 channels. I have the standard 3.5" front speakers in the panel with the above-mentioned lights, and a pair of 5 x 7.5" speakers in approx 2 cubic foot boxes in the living compartment about 6 feet back. I was planning to upgrade the drivers in these in the hopes of improving the sound somewhat. Any good suggestions for the 3.5" cockpit speakers?

Thanks

Gordon


Gordon Gibson 1976 23" Norris Upfit Montreal West, Quebec, Canada
Re: Two newb questions [message #321224 is a reply to message #321222] Fri, 28 July 2017 21:10 Go to previous messageGo to next message
RF_Burns is currently offline  RF_Burns   Canada
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
Senior Member
Unless it was changed by a PO, the OEM wiring to the driver's and passenger ceiling lights comes from the engine battery, no the house battery.
Yes 18.5V is way high. Do you have a charger connected to the engine battery? Check the voltage at the engine battery. Something is wrong.. or your voltmeter is faulty.


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
Re: Two newb questions [message #321226 is a reply to message #321224] Fri, 28 July 2017 21:42 Go to previous messageGo to next message
gibsongo is currently offline  gibsongo   Canada
Messages: 116
Registered: October 2012
Location: Montreal West, Quebec, Ca...
Karma: 0
Senior Member
Bruce
No charger connected. The house and engine batteries are connected by a combiner though. I'll check the VOM tomorrow, but it was fine a week ago.
Thanks
Gordon


Gordon Gibson 1976 23" Norris Upfit Montreal West, Quebec, Canada
Re: Two newb questions [message #321229 is a reply to message #321226] Fri, 28 July 2017 23:34 Go to previous messageGo to next message
Bullitthead is currently offline  Bullitthead   United States
Messages: 1411
Registered: November 2013
Karma: 5
Senior Member
Maybe somehow your chassis battery positive is connected to the junction between the two 6 volt batteries.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.
Re: Two newb questions [message #321230 is a reply to message #321229] Fri, 28 July 2017 23:37 Go to previous messageGo to next message
Bullitthead is currently offline  Bullitthead   United States
Messages: 1411
Registered: November 2013
Karma: 5
Senior Member
That would give you 18.6 volts and the ground connection for one of the 6 volt batteries would have to be disconnected.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.
Re: Two newb questions [message #321231 is a reply to message #321230] Sat, 29 July 2017 02:54 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
Bullitthead wrote on Fri, 28 July 2017 23:37
That would give you 18.6 volts and the ground connection for one of the 6 volt batteries would have to be disconnected.


I like that thought.

I have been trying to come up with a failure scenario with no alternator or converter running. My only explanation was the meter is bad.

Your guess is a good one.

Maybe he should check the cabling on all batteries (house and engine) for proper connections.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: Two newb questions [message #321236 is a reply to message #321222] Sat, 29 July 2017 08:58 Go to previous messageGo to next message
Scott Nutter is currently offline  Scott Nutter   United States
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
Senior Member
Gordon,
There was a pretty good thread on stereos a few days ago.
Alpine has a round 4inch speaker that should fit in there. About $50 US on Amazon. Crutchfield also has 4x6 inch speakers that will fit but you will have to mod the panel insert.
My panel insert is cracking at the corners, so im going to get a thin piece of wood and cut it to fit and make that my overhead panel insert. Then I'm going to try to get a pair of Alpine 5x7 speakers to fit into the wood. If the Alpine is too wide, then I'm going with a 4x6.
Then there's the light........applied has screw on lights.
Good luck,
Scott


Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas
Re: Two newb questions [message #321244 is a reply to message #321236] Sat, 29 July 2017 13:09 Go to previous messageGo to next message
SpookyEng is currently offline  SpookyEng   United States
Messages: 208
Registered: June 2016
Location: Navarre, FL
Karma: -5
Senior Member
Jim Bounds just did a blog post on the GMC's speakers:
http://www.gmccoop.com/gmc-motorhome-honda-generators-for-sale/


JD Lisenby- USAF Ret 1978 Royale-455 MacDash, Manny Tranny, FI-tech, 3.70 etc etc Navarre, FL
Re: Two newb questions [message #321250 is a reply to message #321222] Sat, 29 July 2017 15:16 Go to previous messageGo to next message
Scott Nutter is currently offline  Scott Nutter   United States
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
Senior Member
Gordon,
I just got back from the GMC, and measured again. The 5x7's won't work..............too wide.

So I think the widest you can put in the overhead is a 4x6 or round 4inch speaker..

Scott.


Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas
Re: Two newb questions [message #321262 is a reply to message #321222] Sat, 29 July 2017 20:04 Go to previous messageGo to next message
ree_eric is currently offline  ree_eric   
Messages: 43
Registered: February 2004
Location: Alexandria, Ontario, Cana...
Karma: 0
Member
I put 2 modern 4" speakers, 4 holes have to be drilled in the plastic to secure them and they look fine.

Eric & Ree '74 ex-Sequoia (parts) '75 Eleganza (TB, exhaust x-over blocking plates, Manny reaction arms and discs, 3"exhaust rear muffler, aux vacuum, fuel tank sealing, rebuilt senders and new rubber, propane hot water heater.) Alexandria, Ontario, Canada
Re: Two newb questions [message #321328 is a reply to message #321231] Sun, 30 July 2017 19:28 Go to previous messageGo to next message
gibsongo is currently offline  gibsongo   Canada
Messages: 116
Registered: October 2012
Location: Montreal West, Quebec, Ca...
Karma: 0
Senior Member
How embarassing....
Two shorted segments in the digital VOM's readout and a 13 turns into an 18 (when plugged into shore power the chassis and house batteries are reading aboutg 13.4 volts. Next time I will be a bit more careful before claiming that the sky is falling.

But I guess one stupid guestion fosters another. The switch controlling the light above the passenger and driver is three position - center, up and down. I assumed center would be off - and there is no voltage to the bulb socket in this position, so I guess that is right. In one of the two "on" positions I see coach battery voltage, and in the other, 0 volts. So what exactly is this second "on" position for?

In terms of the speakers, I am trying to keep the front cap unmolested just in case I want to sell to a purist on down the road. SO I found some Polk 4" 2-way drivers to replace the 3.5" ones. Better...but not by a lot. Saw the Bounds video, but he didn't mention a brand for his replacement drivers (although $25 each sounds like a great deal - half the price of the Polks). So I will beef up the 5 x 7" two way drivers in the add-on cabinets in the front living compartment to hopefully add a little more bottom.

Thanks to all.

Gordon


Gordon Gibson 1976 23" Norris Upfit Montreal West, Quebec, Canada
Re: [GMCnet] Two newb questions [message #321333 is a reply to message #321328] Sun, 30 July 2017 19:58 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Gordon,

The cockpit overhead lights can be either ON, OFF, or AUTO-EntryDoor.

Ken H.


On Sun, Jul 30, 2017 at 8:28 PM, Gordon Gibson
wrote:

> How embarassing....
> Two shorted segments in the digital VOM's readout and a 13 turns into an
> 18 (when plugged into shore power the chassis and house batteries are
> reading aboutg 13.4 volts. Next time I will be a bit more careful before
> claiming that the sky is falling.
>
> But I guess one stupid guestion fosters another. The switch controlling
> the light above the passenger and driver is three position - center, up and
> down. I assumed center would be off - and there is no voltage to the bulb
> socket in this position, so I guess that is right. In one of the two "on"
> positions I see coach battery voltage, and in the other, 0 volts. So what
> exactly is this second "on" position for?
>
> In terms of the speakers, I am trying to keep the front cap unmolested
> just in case I want to sell to a purist on down the road. SO I found some
> Polk
> 4" 2-way drivers to replace the 3.5" ones. Better...but not by a lot. Saw
> the Bounds video, but he didn't mention a brand for his replacement drivers
> (although $25 each sounds like a great deal - half the price of the
> Polks). So I will beef up the 5 x 7" two way drivers in the add-on
> cabinets in
> the front living compartment to hopefully add a little more bottom.
>
> Thanks to all.
>
> Gordon
> --
> Gordon Gibson
> 1976 23" Norris Upfit
> Montreal West, Quebec, Canada
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: Two newb questions [message #321337 is a reply to message #321222] Sun, 30 July 2017 20:11 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
The headlight switch when rotated turns on the courtesy lights in the other away from center position.
Try Crutchfield or Retrosound for sourcing car speakers. No matter what you put up n the 3.5"overheads they are fatiguing due to position and size.


John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] Two newb questions [message #321342 is a reply to message #321333] Sun, 30 July 2017 20:44 Go to previous messageGo to next message
gibsongo is currently offline  gibsongo   Canada
Messages: 116
Registered: October 2012
Location: Montreal West, Quebec, Ca...
Karma: 0
Senior Member
Aaaah - makes a lot of sense. Thanks.
Gordon


Gordon Gibson 1976 23" Norris Upfit Montreal West, Quebec, Canada
Re: [GMCnet] Two newb questions [message #321352 is a reply to message #321328] Sun, 30 July 2017 21:35 Go to previous messageGo to next message
Emery Stora is currently offline  Emery Stora   United States
Messages: 959
Registered: January 2011
Karma: 4
Senior Member
In some GMCs the light comes on when the door is opened. I believe that was earlier models.
On my 1977 when the light switch is in one of the on positions the headlight switch (which controls dimming of the dash lights) will turn on the overhead lights if the headlight switch is rotated all the way.

Emery Stora
77 Kingsley
Frederick, CO

> On Jul 30, 2017, at 6:28 PM, Gordon Gibson wrote:
>
> How embarassing....
> Two shorted segments in the digital VOM's readout and a 13 turns into an 18 (when plugged into shore power the chassis and house batteries are
> reading aboutg 13.4 volts. Next time I will be a bit more careful before claiming that the sky is falling.
>
> But I guess one stupid guestion fosters another. The switch controlling the light above the passenger and driver is three position - center, up and
> down. I assumed center would be off - and there is no voltage to the bulb socket in this position, so I guess that is right. In one of the two "on"
> positions I see coach battery voltage, and in the other, 0 volts. So what exactly is this second "on" position for?
>
> In terms of the speakers, I am trying to keep the front cap unmolested just in case I want to sell to a purist on down the road. SO I found some Polk
> 4" 2-way drivers to replace the 3.5" ones. Better...but not by a lot. Saw the Bounds video, but he didn't mention a brand for his replacement drivers
> (although $25 each sounds like a great deal - half the price of the Polks). So I will beef up the 5 x 7" two way drivers in the add-on cabinets in
> the front living compartment to hopefully add a little more bottom.
>
> Thanks to all.
>
> Gordon
> --
> Gordon Gibson
> 1976 23" Norris Upfit
> Montreal West, Quebec, Canada
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

Re: [GMCnet] Two newb questions [message #321384 is a reply to message #321342] Mon, 31 July 2017 08:08 Go to previous messageGo to next message
rod utterback is currently offline  rod utterback   United States
Messages: 18
Registered: April 2016
Karma: 1
Junior Member
Hi
Gordon, I’ve been reading all the comments regarding speakers. I recently made a major upgrade to my system. And offer to pass on my struggle (I mean information learned). Please read this with reservation, I’ve found because of production changes and wild POs changes, things can vary greatly. This is just what I did. Although I was once told I didn’t do it because I didn’t offer pics.

I spent a lot time on research in person and on line to try to find a substitute speaker for the cockpit. With the mounting points and shallow depth I cant see how anything larger the a 3.5 inch will fit. 3 inch are non existent. No on a 4 inch. Keep the factory look. It’s a better way, usually takes more time and money to return to original when you’ve tired of the look later, looks integrated into the couch, and I think represents a greater value in the long term. In San Diego we have a supplier named Fry’s Electronics ( outpost.com). You can order online and they can provide a quality high power speaker that fits both your cockpit size and the rear compartment 4x6 with the use of a speaker mounting board. All out of sight with no visible sign of chopping the interior. Stealth is the way to go.

The seat pedestals make a great place for 6 x 9 multi driver speakers for fill. They can be full range but I prefer disabling the tweeter and crossing over at least 60 hz. The cockpit speakers should be crossed-over at 180 hz. They are too small for anything else and are used for stage presence imaging . Then dedicate one of the lower storage compartments for subwoofer drivers. Add quality amps and a little tuning and you are done.

The rest of my mods were electronics ( amps, double din, wifi, Bluetooth, gps, etc,etc)

Good luck with what ever you chose.
Rod Utterback
1973 canyonlands 26 ft mucho mods
Escondido, Ca.

From: Gordon Gibson
Sent: Sunday, July 30, 2017 6:45 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Two newb questions

Aaaah - makes a lot of sense. Thanks.
Gordon
--
Gordon Gibson
1976 23" Norris Upfit
Montreal West, Quebec, Canada

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Re: Two newb questions [message #321451 is a reply to message #321337] Mon, 31 July 2017 16:45 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
I am going to make this long story very short. (If you want to hear the long version, feel free to buy me beer at the next rally.)

I have not heard real well for years, but I can still appreciate music.

The radio was dead when we got the coach.
I got a new radio and then realized that the existing speakers were A:Grounded at one side and B:Junk when they were new.
I ran wire and got two new 3.5" Alpine coaxials.
Not only could we each only hear one side but what we could hear was terrible.
I made a temporary mount and put the pair of Tri-ax 4x6s there. The one side that each of us could hear sounded better. But it still sucked.
I scored the last pair of Tri-ax like the first in town and made up the four mounting plates you can see in the picture.
http://www.gmcmhphotos.com/photos/speakers/p35249-where-i-put-new-speakers.html

I thought the little lights in the sides were useless from the get-go.

Yes, you do have to damage the head liner, but it works great.

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
Re: Two newb questions [message #321494 is a reply to message #321222] Tue, 01 August 2017 15:59 Go to previous message
Scott Nutter is currently offline  Scott Nutter   United States
Messages: 782
Registered: January 2015
Location: Houston/San Diego
Karma: 4
Senior Member
And the 4x6 speakers that Matt used can still be bought at crutchfields.

Pioneer TS-A4676R. 4"x6" 3 way speakers. $79.99. Gets 5 out 5 stars.


Scott Nutter 1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, Dave Lenzi super duty mid axle disc brakes, tankless water heater, everything Lenzi. Alex Ferrera installed MSD Atomic EFI Houston, Texas
Previous Topic: This thing was near my house today
Next Topic: Bring me up to speed on the Tracker
Goto Forum:
  


Current Time: Thu Oct 31 17:48:08 CDT 2024

Total time taken to generate the page: 0.07330 seconds