MC9 toad wire routing from center tap to 24/12v converter in engine compartment.

plyonsMC9 · June 11, 2012, 01:41:45 PM

Greetings bus folk!

I need to route my 10 guage 12 volt wire from the center tap up front to the rear engine compartment for my 24-to-12 volt converter to power turn signals, etc..

Wire is to the rear bay. But, how do I gracefully (?) get from the rear bay to the engine compartment? What is the recommended path?

Suggestions are greatly appreciated!

Best Regards, Phil

PS Moose bus leaves for Arizona in 7 days!

Ed Hackenbruch · June 11, 2012, 01:49:38 PM

Phil, you do know that it is a little warmer there this time of year unless you are up in the mountains? And it is going to get warmer yet.....

JackConrad · June 11, 2012, 01:51:45 PM

Phil,
Not sure about how graceful it is, but the wire can be run through rear bulkhead, attached to air lines/ power sreering lines, AC lines/water lines, etc. over rear axle and into engine comartment. Wire can be installed inside plastic wire loom or plastic conduit for better protection. Install an appropriate size fuse/circuit breaker at the center tap in case a short should occur. Someone else may have a more "graceful" solution ;-) Jack

bevans6 · June 11, 2012, 01:57:54 PM

I fished a small bundle of wires for that purpose from the AC bay (where a 12V tap is, coincidentally, although I didn't use that one) to the engine compartment using the AC coolant tube for the conduit. Worked a treat, to be honest. Obviously I am not using the factory AC any longer...

Brian

plyonsMC9 · June 11, 2012, 07:00:10 PM

Thanks Ed, we will indeed be up in the mountains - about 5,100 foot elevation.

Thanks Jack & Brian, both very good suggestions. We'll see what is the most "doable" in our situation & will keep the group posted.

Kind Regards, Phil

gumpy · June 11, 2012, 07:29:03 PM

If the ducts are still in place along the floor, consider running the wire through there.

Otherwise, the rear bay wall and over the differential works. Run flex conduit (smurf tube) to
protect it from the elements.

craig

thomasinnv · June 11, 2012, 08:59:13 PM

why not use the existing 12 volt option wire that is already there? it runs to the front panel, the ac panel in the front bay, and the rear panel in the engine compartment. I believe it is a 10 gauge wire.

thomasinnv · June 11, 2012, 09:17:14 PM

Just looked in the MC9 manual, it is post 6 in the ac junction box, a 10 gauge line. If there is no wire from the batts it would be really easy to run one to this location, the lines should already be there to all the other junction boxes from there.

stud 55 circuit 23 in the front junction box, stud 41 circuit 23A in the rear junction box.

These are the same existing circuits I used when wiring my towed light relay setup, works just fine.

All the circuits needed for wiring the towed will be found in the rear junction box as well, I just tapped into the rear box for my setup.

gumpy · June 15, 2012, 06:34:13 PM

Quote from: thomasinnv on June 11, 2012, 08:59:13 PM
why not use the existing 12 volt option wire that is already there? it runs to the front panel, the ac panel in the front bay, and the rear panel in the engine compartment. I believe it is a 10 gauge wire.

The wire from the A/C J box to the Rear J Box is only 16 ga. While that will run LEDs, it's marginal on incandescent toad lights.

thomasinnv · June 16, 2012, 12:30:45 AM

Quote from: gumpy on June 15, 2012, 06:34:13 PM
The wire from the A/C J box to the Rear J Box is only 16 ga. While that will run LEDs, it's marginal on incandescent toad lights.

I been running that way for a couple years now and I've had no problems at all. There may be some voltage drop, but the only time you are using those lights is usually with the bus running, in which case the alternator is putting out a higher voltage anyway. I can think of a few other people that have wired the same way as well.

bevans6 · June 16, 2012, 04:12:52 AM

Derrick, I don't think Craig is saying it won't work, he's probably saying the load from a string of incandescent lights and turn signal/stop lights on a long 16 Ga. wire at 12 volts could over-load it, with a potential fire hazard. Glad to hear it's working for you, though. It kind of depends on what lighting you are running on your trailer/toad. My tow dolly runs about 5 amps, which would be fine - my big landscape trailer runs around 25 amps, which would overload the 16 ga wire.

Brian

luvrbus · June 16, 2012, 07:33:49 AM

We were in Prescott Valley Friday was 90 degrees in valley about 80 in the mountains came back to Scottsdale 107 degrees nice area Phil and you have a 2 stroke shop there also (Geoff)

That is the part I love about Az no matter where you live here it is only a 1 hr drive for heat or cooler weather and plenty to do all year around

thomasinnv · June 16, 2012, 09:36:59 AM

Quote from: bevans6 on June 16, 2012, 04:12:52 AM
Derrick, I don't think Craig is saying it won't work, he's probably saying the load from a string of incandescent lights and turn signal/stop lights on a long 16 Ga. wire at 12 volts could over-load it, with a potential fire hazard. Glad to hear it's working for you, though. It kind of depends on what lighting you are running on your trailer/toad. My tow dolly runs about 5 amps, which would be fine - my big landscape trailer runs around 25 amps, which would overload the 16 ga wire.

Brian

Good point. I'm only running two tail/stop/turn lamps on my toad. I'm sure if I was running 25 amps like your trailer I would probably have a meltdown. If I was gonna run a heavy 12 volt load on a trailer than I would most likely run a heavier gauge wire.

plyonsMC9 · June 16, 2012, 08:38:38 PM

Thanks Derrick - we did test it out and that stud was not "live". we routed through a channel along the side as I think Jack may have suggested. The 24v to 12v converter we purchased from Craig works like a champ! Just hooked it up today.

Kind of amazing to have something work so well after a lot of other problems - brake buddy arrived broke, spare tire was in front storage area but turned out was wrong size for our bus - problems finding replacement, and I could go on, and not all were bus - related (washer broke on last day @ temp housing & so we have to fix), but we are bound & determined to leave on Monday!

Playing some bluegrass gospel @ church throughout all the morning services - I'll be playing the doghouse bass - really looking forward to our last day at our church. Then on the road Monday.

Thanks luvrbus about the Prescott Valley report. And - I had NO idea Geoff was in the area. Do you have contact information for him?

Thanks all!

Phil

gumpy · June 17, 2012, 04:30:34 PM

Quote from: thomasinnv on June 16, 2012, 12:30:45 AM
I been running that way for a couple years now and I've had no problems at all. There may be some voltage drop, but the only time you are using those lights is usually with the bus running, in which case the alternator is putting out a higher voltage anyway. I can think of a few other people that have wired the same way as well.

The main problem is that with the smaller wire and associated voltage drop, what can happen is that when you put on a turn signal, the opposite side will dim in sync with the blinker you
turned on, and it can be confusing to people behind you. It can be bad enough that they can't tell if you're signaling left or right. Overloading the 16 ga wire is also a potential issue as
pointed out by Brian. This could be a potential fire hazard, or could blow a circuit breaker, leaving you with no lights at all on your toad.

For the units I build, I recommend running a 10 ga wire from the batteries or A/C Junction box to the rear Junction Box or directly to the toad converter input.

Quote
The 24v to 12v converter we purchased from Craig works like a champ! Just hooked it up today.

Phil, glad to hear it's working well for you. Hope your trip to AZ goes well.

craig