Two cheerful vacationers

A Quick Note After Vacation

Hello and welcome back (to us) from vacation! We decided to pop a quick note in the journal to refer back from other entries which we’re going to do retrospectively for the summer months of 2022. We didn’t write anything up because we were BUSY. Crazy busy. The kind of busy that leaves you absolutely exhausted with no time to even remember you have a journal. So, we’re going to go back and pick the most interesting or informative job from each month and fill the gap.

As for the vacation itself, it was a mixed bag. We decided to go to Key West, FL, this year. We’ve never been and watching all our travel YouTube channels, it seemed like a cool thing to do for a week. Sadly, it was not a great location for us. We ate, drank, walked, rode, drove, and stumbled our way all through that little island, and the hard fact was we were paying way too much for unexceptional experiences. On the upside, we did make it down to Bahia Honda (bay-ee-uh own-duh) State Park for a little snorkeling on the last day, but we can’t credit that to Key West. BH is a reasonable day trip from Homestead and doesn’t require the $150+/night campground on Stock Island.

It was, nonetheless, a very helpful break. We got so incredibly bored by the end of day 4, we went to Publix, bought groceries, and basically opted out of the rest of the island. We also got so incredibly bored, we accidentally rested up. When the trip was over, all of the sudden there was a burst of productivity and lots of nagging old items on the to do list suddenly found themselves handled. The vacation may not have been worth the money, but it definitely accomplished something.

If you do happen to visit Key West, I will say the only two worth-it food experiences we had the whole time we were there (out of $1400 in restaurants and bars) were Roostica on Stock Island and Croissants de France de Stock Island. Roostica is a very interesting place to get wood fired pizza. We happened to be there on “gravy night”, which is a spaghetti dinner special. Don’t be alarmed by the absence of pepperoni from their menu because they absolutely have pepperoni pizza. They use a special salami in place of pepperoni and, trust me, you won’t be disappointed. As for the Croissant place, it was a little pricey, but their sandwiches were definitely not something you’d find at a common deli.

So here we are. Rested, poorer than we expected (if you missed it, go check out the October entry), and ready to have a great year.

Hope to see you out there sometime soon!

Half cleaned filthy AC evaporator coil

Professionally Cleaning an RV Rooftop Air Conditioner

The picture attached to this post is what we found while servicing a rooftop air conditioner for someone who thought they were properly maintaining it. They stopped by to ask if the AC special we posted on our sign included “anything special” because every month during the summer, they washed the air return filters and sprayed off the condenser coil with a hose (without removing the outer cover). They were a little shocked to learn exactly how much is involved in a real semiannual AC service. The attached picture is of the evaporator coil, which is the coil you can see looking up through the air return on units with an exposed “bottom unit”. It obviously needed our help.

Here is a rundown of the things we clean and check when doing semi-annual maintenance on a rooftop air conditioner, regardless of brand. The list isn’t exhaustive because some units have extra features like condensation pumps which require extra steps.

  1. Remove the rooftop cover, remove any debris, especially wasp/dirt dauber nests. These pests can block airflow and airflow is everything.
  2. Measure the compressor amp draw at start and run. High loads can indicate impending compressor failure, low loads can indicate low refrigerant.
  3. Measure the “Delta T”, the difference between intake air temperature and cooled air temperature. This should be around 22 degrees in most cases, but if it’s higher than 30 degrees, it’s probably a sign of air leaking between the intake and cooled sides. If it’s lower than 20 degrees, it’s probably a sign of bad airflow through the unit. (These temperatures vary with humidity!)
  4. Measure the “Delta I”, the difference between the ambient air outside the intake, and inside the intake. A difference of more than 2 degrees means air is leaking between the intake and cooled sides and the leak must be found and taped or otherwise sealed.
  5. Inspect for oily residues. Refrigerant leaks leave behind the oil used to lubricate the compressor.
  6. Check the condenser fan blade spins freely. Fan motors have brushes and bearings which wear over time.
  7. Clean the condenser coil and straighten any fins which can be straightened without causing further damage. There are several no-rinse condenser coil cleaners on the market. Our favorite has a brush built into the cap which also helps to straighten fins. Every square inch of blockage or restriction adds up to loss of cooling efficiency and puts extra load on the fan and compressor.
  8. Remove the evaporator shroud, noting any gaps which would allow air to pass through the shroud. Remove any debris.
  9. Expose the capacitors then discharge, disconnect, and check tested capacitance against rating. Double check correct capacitors are installed. The best chance of saving a fan motor or compressor is to catch a failing capacitors as soon as possible. A bad capacitor will burn out a compressor given enough time. Replace any that are not up to spec.
  10. Clean the evaporator coil and straighten any fins which can be straightened without causing further damage. There are several no-rinse evaporator coil cleaners on the market. Our favorite is anti-fungal, anti-viral, anti-bacterial, and fresh scented. Just like the condenser coil, every square inch of blockage or restriction adds up to loss of cooling efficiency and puts extra load on the fan and compressor.
  11. Check the wiring connections. Loose connections can lead to arching which can start a fire, damage components, or cause intermittent function. Considering there is an earthquake/hurricane with every move, loose connections are more common than you might think. (This is also a great time to check the connections in the breaker box and other fire hazard locations!!)
  12. Replace the shroud, being extra careful to tape all gaps. A lot of factory installs will have a little piece of tape on the corners, but it’s just tape: tape the full seams!
  13. Clean or replace the air return filters inside.
  14. Retest the Delta T and Delta I to make sure everything is working properly. Under normal usage in just about all parts of the country, if the last cleaning was 6 or more months ago, there will be an improvement.

Of course, when we do it, we like to write up our findings so the owner can keep the health stats in their maintenance records. If you do this job yourself, pretend for a moment you’re issuing yourself a report, be detailed, and put it with your maintenance records. Being able to look back at prior tests for a trend is sometimes very helpful and having good maintenance records can also increase the value of your camper when it’s time to sell or trade!

A remote control chip and receiver chip with voltage converters.

That Moment When You Realize There Was Never a Wire!

So far, this has to be the most interesting job we’ve ever done. The story has so many angles, it’s hard to decide where to begin. Because it’s sure to be a “too long didn’t read”, I’ll break it down into sections.

The Customer Concern

A very nice fellow staying across the campground from us at Buccaneer State Park in Waveland, MS, stopped by one day to ask us to have a look at his front furnace, which would not fire up. He had bought his 2006 Fleetwood motorhome from an estate and knew nothing of its past. The front furnace not firing might be related to something a little odd in plain sight.

The front air conditioner installed at the factory was a Coleman Mach configured as Zone 1 with a Zone 2 in the bedroom. It had been changed out for a Dometic at some point and a second thermostat installed for it. The thermostat was aware of the furnace, but the furnace would not activate. The owner believed the installation of the Dometic was in some way incomplete or faulty and wanted us to check it out.

The Purple Monkey

A “Purple Monkey” in the NRVTA world means basically a wild goose chase. We checked out the Dometic and everything had been configured properly for it to control the front furnace. However, the relay in the AC control box that should be connected to a wiring harness to send the 12VDC activation signal to the furnace was not connected to anything at all. The Coleman harness was still there, so it looked like all that needed happen was hooking up the usual wire and we’d be all set.

One should NEVER just apply voltage to a wire in an RV without verifying the wire isn’t shorted somewhere and actually terminates where you think it does. The good news: the wire wasn’t shorted to ground and had no voltage on it. The bad news: it also didn’t terminate anywhere near the furnace. A tone generator was able to “hear” the wire to somewhere near the edge of the roof, but then it just disappeared. We decided to trace it from the furnace up when we found the REAL problem.

Are You Serious?!

The furnace connection on this Atwood is a 6 pole plug which SHOULD have four wires on it: all 12VDC, positive house power, chassis ground (aka negative), power out to the AC control box, and a line in from AC control box. The wire coming back from the AC control box, which normally activates the furnace with 12VDC, was MISSING. We pealed back the vibration shielding on the umbilical to the slide out where the furnace was mounted and it wasn’t there either! Apparently, the factory forgot to include the wire in the lower section of the harness altogether.

We went outside and scoped the exhaust port, and sure enough, this furnace had NEVER been hot. It was basically brand new at 15 years old.

No Way It’s Worth It

Running a new wire inside a fully built coach is a nightmare. If it can be done at all, it takes a lot of time (hence expense) to do it. This job would’ve definitely been on the long side because it’s pretty much three separate jobs to get the wire from the roof to the wall, from the top of the wall to the bottom of the wall, and then out into the slide out. Just making it right would’ve cost hundreds (if not thousands). It was time to think outside the box.

What Are My Options?

  • Installing a third thermostat which only operated the furnace would’ve also taken a lot of time and the placement of that thermostat could not have been very effective in the floor plan of the coach.
  • A manual On switch that simply fired up the furnace by giving it the 12VDC signal is not necessarily a safe way to solve the problem. If the furnace’s thermal cutoff failed in the on position, it would definitely be a fire hazard.
  • Just don’t use it? The whole reason it became a concern is the owner planned more cool weather camping this year. Electric heat is good, but nothing compared to the power of propane.
  • Do something WAY outside the box. << This one!

Scotty, Beam Me a Furnace Activation Signal

I’d been cruising Facebook a few days before and just happened to get offered an Amazon ad for a pair of chips that use a 433MHz encrypted radio signal to activate something via a relay. The transmitter side of it is basically the guts of a key fob for power door looks. The receive side just knows how to open a small digital relay. This was the perfect time to go mad scientist!

We paired the little chips with voltage regulators to bring the house 12VDC power down to a friendly and consistent 9VDC. This step might have been unnecessary because the chip claimed its maximum voltage was 12. We know the alternator on a motorhome produces 14VDC and if the owner ever installed LiFePO4 batteries, they need 14.4V to balance the cells. We thought it best to spend the extra ten bucks on some cheap insurance and use regulators.

The remote control chip was powered up by running house 12VDC into one side of the AC control box heater relay. The other side of that relay powered the regulator which powered the chip and activated the radio signal.

The regulator for the receiver control chip was connected near the furnace to 12VDC house power through a kill switch mounted on the outside of the cabinet the furnace is hiding under. One side of the relay was also connected to the same 12VDC source (which the chip was rated to handle). The other side of the relay was wired into the furnace connector finally providing that fourth missing wire.


It seems after all that, the conclusion should be more exciting, but it simply worked. The total cost of the project was around $150 including parts and our time to find and test the setup, a figure that was well worth it to the owner and vastly less than any other route to a solution.

We really enjoyed this project because the nerd factor was 11 out of 10. There are a few takeaways in retrospect:

  1. Never assume anything.
  2. Do the proper diagnostics if you want to avoid the dreaded Purple Monkey. We would’ve looked like idiots if we’d just tried replacing the furnace control board. Who knows, maybe the change to the Dometic AC was also an attempt to make that furnace work.
  3. Don’t just think outside the box, understand there IS NO BOX!

A Deeper Look in the Mirror

After writing up our website, we read the whole thing and realized it was missing something: the flavor of who we are and how much we love what we do.

Probably a reflection of happy childhood memories, we are absolutely passionate about camping, fellow campers, and the gear we all use to make it happen. We travel almost full time and sometimes we go to spectacular places like Glacier National Park. Those places are awe inspiring wonders, but they’re not enough to make full time RVing worth it.

If we are in a campground with you, you’ll see us out walking around any day weather permits. For us, the bigger splendor is in the people enjoying themselves and the vast array of rigs and campsite setups we see. It’s exciting to see classics still serving their owners, the latest and greatest straight off the dealer lot, rigs designed for a family with half a dozen kids, coaches built for two, and even the latest tent designs. Every single campsite is a little world of wonder to us as we walk by and often stop to visit.

The reason we travel so much isn’t the spectacular sights or even the geeking out on the vast array of RVs and camping toys. It’s the people we get to meet from all over the country and sometimes, all over the world. Everyone who camps seems to have some personality traits in common, each person expressing those traits in their own unique ways reflecting their own unique experiences and values. Learning about the people we meet and how their world is put together is the thing that keeps us out here on the road so much.

The vast majority of people we meet are:

  • Adventurous
  • Independent
  • Brave
  • Flexible
  • Adaptable
  • Smart
  • Thoughtful
  • Tough
  • Witty
  • Friendly
  • (and the list could go on)

It’s easy to see why these traits are common on the road. It takes all of that to get the most out of camping.

These traits are also why the best part for us is… you!

So We Did a Thing…

Today was a big day. For months we’ve wanted to break from the daily flood of work and recovery to lay down our little patch of Internet homestead by completing our website. Finally, after months with only a heartfelt letter to our visitors serving as more than a “Coming Soon” page but less than a website, Round Two is complete!

It was probably good fortune that made it take so long because when we formed this venture, we knew we’d need a website, but the correct contents of that site did not turn out to be anything we would’ve thought of at the onset. What has been compiled here in this release is basically the answers we give to the passersby who see the sign in the windshield and stop in to ask for help or just have a chat about what we do and what it’s like to do it the way we do.

As I sit here taking my personal victory lap for finishing things up, I can’t count the times we’ve told visitors and customers how to find repair techs when we’re not around. Almost as often, we’ve recommended products or told someone where to buy a part we don’t carry with us. Of course, people want to know what we can do and what our backstory is, but our biggest fear is that one of these awesome people would someday want to talk to us and not remember how to do it.

Finally, as the situations have unfolded, we’ve met amazing people with interesting challenges worth having on record. That’s what this From the Field journal is about. It’s kind of for us, but it’s also for those who might want to get more in touch with who we are and how we do things. We hope you like it.

Safe travels,
RV Tech 4 U