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Topic: Hot wire under dash lid (Read 905 times) previous topic - next topic

Hot wire under dash lid

Hey folks taking a break from my furnace troubles  . And now starting radio install with amp. And need some where to power the amp close to the radio . The manufacture would like you to go directly to the battery for your power source . But there should be a place to pick up a good 12v power supply under the dash lid  8)
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Hot wire under dash lid

Reply #1 –
There's a "very famous" solenoid under the dash that has been posted about many, many times here on the forum.  It has a notorious reputation for it's low reliability.  It would be good for you to get to know it.  When you turn on the ignition, this is the thing that goes "klunk" and powers every thing.  The lug that is always ON would be my first choice as being as close to the battery as you can get without running another cable all the way back to the battery.  It's normal for both terminal to have quite a stack of wires under each lug - could be the most challenging part of adding another one.  Equally important is the ground connector for the amp - look for a large insulated flat braided wire - that's your best ground.  Another option for a good ground is getting to the chassis steel somewhere.  Most likely on the other side of the firewall for that. 
Here a post with a photo of what the solenoid looks like:  help - dead along road
P.S. Upgrading this solenoid to the Blue Sea unit (mention several times in post regard this solenoid) is on my list of upgrades.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Hot wire under dash lid

Reply #2 –
There's a master relay under the dash pad. Just make sure to be careful, there's enough amps under there to weld with.
Unhook the battery. Is that to many theres?
1994 U280
Build #4451
"If everyone is thinking alike, then somebody isn't thinking"

Re: Hot wire under dash lid

Reply #3 –
Quote from: Hammer2100 –
There's a master relay under the dash pad. Just make sure to be careful, there's enough amps under there to weld with.
Unhook the battery. Is that to many theres?
write the best you can Hummer. and thanks guys for any & all help . I see that relay & WOW theirs a lot of wires hook to it on both sides of it but running a wire all the way back to the batt is just crazy  :o
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Hot wire under dash lid

Reply #4 –
You have received good answers if you want the radio powered from the chassis battery.

Wire to the battery side if you want the radio feed to be hot all the time (from chassis battery).  To the other large lug if you want it how only when ignition on.

Now, if you want it to operate off the house battery instead of chassis battery, you will need to find another source.

If you have a means of charging your chassis battery, that would probably be the easiest heavy feed.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Hot wire under dash lid

Reply #5 –
Wolfe i can keep the house batt good & hot . & i found the main batt cable coming up & to the left side of the solenoid . so if i come off the right side of it that would be key power . also the power i need is for three audio amps . the radio has power all ready .
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Hot wire under dash lid

Reply #6 –
The ignition solenoid (the one under the lift up part of the dash) is powered by the chassis, not house battery bank.  OE did not charge the chassis battery bank from shore power.  No idea of that was changed by a previous owner.

But, if no means of charging the chassis battery from shore power, I would NOT hook up a high amp draw to the chassis battery/ignition solenoid.  There are other house battery-powered wires that you can use.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Hot wire under dash lid

Reply #7 –
Use the wires from the original radio and amplifier. There are two separate circuits, each with a fuse. Look at your drawings and you'll see what I mean. Find the numbers of the wires on the drawings and then look for the little numbered stickers on the wires.
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Hot wire under dash lid

Reply #8 –
I ended up taking what looks to be 2 gauge wire off the solenoid and making a pig tail, my grounding is not the best but I'll keep an eye on this miss . I also found the wire that would have been the mic for the CB the last owner must of cut it, why would some one do that  :-X  Thanks for every ones help
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Hot wire under dash lid

Reply #9 –
Good choice as long as you use it:

1. When driving (i.e. alternator charging chassis battery)
2. If you have a method of charging the chassis battery when on shore power/generator.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Hot wire under dash lid

Reply #10 –
Lovetogo, That hand held mike was no loss probably.  I had three FT 's and none of the CB's units were worth a tinkers d.... Stop in any truck stop and buy as much Cobra CB as you can afford.  I got along with a very small 40 channel unit that I used only at rallies and on the road in bad traffic conditions. Think I paid 40 bucks and then installed a decent antennae.
Gary B

Re: Hot wire under dash lid

Reply #11 –
There are three ground bolts in the extreme left front corner under the dashboard. You can probably fit another ground wire with a loop under the nut on one of those bolts.
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Hot wire under dash lid

Reply #12 –
Quote from: RRadio –
Use the wires from the original radio and amplifier. There are two separate circuits, each with a fuse. Look at your drawings and you'll see what I mean. Find the numbers of the wires on the drawings and then look for the little numbered stickers on the wires.
Radio, what amp are you talking about ?my coach has a Sony radio . there are two hots  red powers & yellow one for memory  . but no amp that i know of. thanks
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Hot wire under dash lid

Reply #13 –
On the drawings of my 1991 U300 the radio is a red wire with a #23 sticker on it if I'm reading correctly. The radio amplifier is also a red wire but it says it's optional on the drawings. There are also a bunch of extra circuits you could use, like #45 and #46... but check your 1992 drawings to see if they're the same. All those circuits I mentioned are powered by the coach battery instead of the cranking battery.
Scott Cook
1991 U300 36' 6V92TA
Old Town Penobscot 16
1984 Honda VF1100C (V65 Magna)

Re: Hot wire under dash lid

Reply #14 –
Radio, and every one that jumped in and helped' thanks very much . I got it all hooked up and it sound sweet now the only i need is to get the four old Sony speakers out and some nice' Oh well see how much i want to spend on replacements  ;) the old Sony where nice back in 1992 . I put a 600watt amp on them and they actually sound pretty good! to be over 20yrs old they took a good thump and  never clipped .       
1992 U300 Anniversary Edition wrong color DDC6v92T Big step up from my 1983 35' fc Blue Bird .

Re: Hot wire under dash lid

Reply #15 –
Quote from: JohnFitz –
There's a "very famous" solenoid under the dash that has been posted about many, many times here on the forum.
Reviving this thread...

Does this solenoid exist on the Unicoaches as well? Specifically interested in my '01
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Hot wire under dash lid

Reply #16 –
Quote from: Elliott –
Does this solenoid exist on the Unicoaches as well? Specifically interested in my '01
Yes, you do have a "ignition solenoid".  Your is not located in the same place as on the Unihomes.  Pull the cover off the big circuit breaker panel directly in front of the passenger seat.  Look down at the bottom of the panel for one (or possibly two) big black electric thingies.  One of them should be hot on one large post all the time, and hot on the other large post with ignition key "ON".

Selnoid in front wiring panel



1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"
 

Re: Hot wire under dash lid

Reply #17 –
Elliott,

On your coach you should have 2 that are solid state rather than the one shown in the link. Look for 2  black square boxes in the same location Chuck directed you to..

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."