Snakes and Fish Tapes

[Wally15]

Not having schematics or drawings of my TT is driving me nuts. I'm a new RV'er (or at least I've moved up from pop-up camping), and I need to run some wiring and I don't have a clue how to even get started.
I know the search engine is my friend, but I haven't been able to find a good thread on fishing wires through ceilings and walls. I'm not sure I even understand the structural make-up of my RV.
For example, I'm putting in a 2nd a/c in the MBR roof. I'm also adding a simple digital wall thermostat to control the temp. I know enough not to put it on an external wall, but before I start drilling holes in walls of my almost new RV, I need to understand how I'm going to get from point A to point B.
Is there a thread out there that I missed? I hard wired my whole house with Cat-5 and coax 4-5 years ago, so I have all the stuff and knowledge to run wires and cables in houses. Spent a week in the attic running drops back to a nice Leviton multimedia panel. Not long after I did that they came out with smart TV's just to make me look dumb.
My '13 Laredo has a curved roof and a rubber membrane over a plywood base (I guess?). I'm assuming there are "rafters" (16" centers"?) running across the TT to support the roof. The internal walls are thin, so I'm assuming there are 2x2 studs going from floor to ceiling. Basic "stick house light" construction. Are there any "cripples" or cross bracing in the walls to stop a fish tape? How do you get through the rafters? I'd have to cross at least one to get to the wall I want to mount the thermostat. I need to go about 3' from the a/c toward the rear of the TT, then 3' toward the curbside, then down about 4'. So three 90 degree turns in about 10' of wiring. Or can you angle across?
As many electrical mods and adds as I've read about on this forum, almost everyone has a much clearer understanding of the TT structure than I do.
A tour of the factory is not possible at this time. Maybe a tour of a somewhat local mobile home manufacturer? How close to TT's are MH's in construction details? Are there any books on TT construction and modification? There are hundreds on houses.
DW will have a hissy fit if I turn the MBR into a Swiss cheese factory.
And a reputable dealer to do the installation is a couple hour drive. Plus I'm cheap, and I want to "learn" my new toy.
This is more of a vent than a rant.
Mike

[MarkS]

A 13 Laredo is probably prewired for a bedroom AC. Look for an outlet box next to the vent with a blank plate. I think most people use the built in thermostat rather than wiring a wall mount one.

[Quad]

I wired a Home Depot Honeywell thermostat. Much better at holding and maintains a temp than the OE one. I'll look and see it a can find the wire color codes I used.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

[Javi]

If your 308RE has 50amp service then most likely it is already braced and prewired for a second A/C.. personally I'd install it using the internal thermostat rather than wiring one on a wall.

[MarkS]

By the Way. CW has a "$39 We'll Install Anything Special". For 40 bucks let them get the AC on the roof.

On your original question. I believe there are curved roof joists. Don't know the spacing. I think you can fish for short distances. The problem is making the turn to go down an interior wall. You may need to cut an access panel to do that.

Also check to see if you can add a breaker to your breaker panel. If you have a 30 amp system, it's probably not going to work.

[Bob Landry]

You are going to have to deal with not having schematics on your trailer because Keystone is not going to give you the first hint of information about anything, even after the warranty period. They will cite their concern about customer safety and tell you to contact a dealer. That said...

If there is a roof vent where you want to install the second AC, there is probably wiring already there for power. If not, you have two challenges, first the framing will have to be braced for a 14X14 cutout that will support an AC, and then you have to ge power to it. Unless you are already set up for 50A service and there is a breaker on the panel marked for a second AC, don't count on it. I'm not sure what centers the walls are built on, but there are cross braces which will not allow a fish tape, so even something like adding an outlet presents major challenges. I've already tried to run wires through the roof. What wiring changes, I've been able to do required a little creativity and most has been run under the trailer by dropping the coroplast and going up through the flooring. The outside walls have foam sandwich between the surfaces, and I would depend on being able to use an existing wire as a messenger and reconnecting it because a lot of the wiring is bundled and goes around corners. I hate to rain on your parade, but it is what it is, and Keystone's customer no-service is going to give you absolutely no useful information.

[jsmith948]

You can get an idea as to how your roof is constructed by removing something easy to get to, such as the inner shower skylight or the inner trim piece around a roof vent. For example, by removing the inner trim on our bath room went, I was able to snake a wire from the vent fan down to a wall switch so the DW didn't have to use a broom stick to turn on the fan. The interior wall was open - no blocking - just vertical studs at the corners.

[Bob Landry]

By the Way. CW has a "$39 We'll Install Anything Special". For 40 bucks let them get the AC on the roof.

On your original question. I believe there are curved roof joists. Don't know the spacing. I think you can fish for short distances. The problem is making the turn to go down an interior wall. You may need to cut an access panel to do that.

Also check to see if you can add a breaker to your breaker panel. If you have a 30 amp system, it's probably not going to work.

The current load for two air conditioners combined, even with one of them being 13.5K BTU, is going to be very close to maxing out your 30A service and you aren't going to be able to run anything else with it. If your trailer has 50A service, then a lot of problems go away.

[Bob Landry]

You can get an idea as to how your roof is constructed by removing something easy to get to, such as the inner shower skylight or the inner trim piece around a roof vent. For example, by removing the inner trim on our bath room went, I was able to snake a wire from the vent fan down to a wall switch so the DW didn't have to use a broom stick to turn on the fan. The interior wall was open - no blocking - just vertical studs at the corners.

I was able to do the same thing when I installed the Fantastic Fan in front of the stove. The wiring I needed to get to was right behind the microwave and I was able to run a fish tape directly towards th side wall. Running a 115V wire to the middle of the roof for an AC is going to be a completely different animal.

[Wally15]

My 308RE has 50 amp service and is prewired for the 2nd a/c installation into the existing roof vent in the MBR. The pre-wiring only has the 120V wire going back to a dedicated 20 amp c/b. No thermostat wiring, or at least none that I can find.

[Javi]

My 308RE has 50 amp service and is prewired for the 2nd a/c installation into the existing roof vent in the MBR. The pre-wiring only has the 120V wire going back to a dedicated 20 amp c/b. No thermostat wiring, or at least none that I can find.
That is correct, most of us just use the built in thermostat in the A/C unit for the bedroom.

[OldCountryBoy]

I had my AC installed in mbr, there is the 120v connection as you indicated, but they had to install a sensor in the wall which in turn connected to the thermostat in the adjacent living room. My thermostat controls two units either together or individually. The downside of this arrangment is I have to go out into the living room to control the mbr ac unit.

I suppose another thermostat in the mbr would be better, but installation could be a trick. Try and find existing wiring and follow it, or as I did once, use it as a pull wire, instead of fish tape, just remember to pull a replacement wire as well.