Saturday, May 19, 2012

Air Conditioner Cleaning and Maintenance

In the last couple of years, the air conditioning unit on my motorhome was getting less effective.

RV air conditioners should not normally require recharging, but the cooling fins should be cleaned out regularly.  Dirty cooling fins are a common cause of poor performance.

The following video from explains the process clearly. The unit on my motorhome is a little different, but the cleaning process is the same.

...and here's a fairly good article at .

You will need a compressor, brushes, a vacuum, rags, a pail of water and a cleaner/degreaser.

When the cleaning is all done using the process described in the video, you can test  the efficiency of the system using two thermometers.  There should be a temperature difference between the inlet and outlet air of 20 degrees Fahrenheit or 6.7 degrees Celsius.  If the difference is significantly less than that, you will want to take your AC to a professional.

Here are some photos and notes from the cleaning I did this week.

Metal Shroud, and plastic shroud in the background
 My unit has two shrouds, with a metal one nested beneath the plastic one (Above and below)

Side mounted screws
Once the unit was opened, I discovered an old wasp's nest, and the cooling fins were very dusty.  That would explain why the unit was not working so well!

Dusty cooling fins
More dusty cooling fins

In the next picture the unit is all cleaned and being reassembled.

The top screws serve only to secure the outer plastic shroud to the inner metal shroud.  I replace the rusty top screws.

Sunday, May 13, 2012

Clearance and Marker Lights Part 2

It is probably obvious to you that I am not a mechanic and I am not an RV technician.  So sometimes I don't get it right have to do things over.  I feely admit that.  Hopefully the mistakes are small.  Hopefully someone else can benefit from my mistakes too.

Take the clearance and marker lights which I wrote about on April 9th.  I replaced the first five out of fourteen and tried to connect the white (negative) wires by wrapping them around the mounting screw. Later I found a couple of these connections were poor.  So I removed the all five lights and installed ring terminals on  the ends of the white wires to ensure a really solid connection.

Ring Terminal

In the picture below, the connection between the white wire and the mounting screw is very poor and unreliable.  This marker light is designed for mounting on a metal automotive surface, where the mounting screw on the right would ground to the metal vehicle body without having to attach to a wire.  Unfortunately my motorhome sidewall is not conductive and not grounded, so the white ground wire is required.  

Before: poor connection for the white wire
I removed the marker light, added a more centred hole for the wires to pass through, then added the ring terminal, crimping it into the wire with my crimping tool.
Crimping the ring terminal onto the wire

Here is the finished light, with two new mounting screws.  I added those because the old mounting screws were no longer holding as well as I would like.
Finished: ring terminal, wire routed through new hole and two new mounting screws. 
And of course lots of silicone!

After completing this, I used the same method to replace the five remaining clearance lights at the front of the motorhome, and four side marker lights.  That completes a total of fourteen lights. Now I can rest assured that the lights will be watertight and reliable for years to come.

Saturday, May 5, 2012

Wheel Covers

Little things can make a big difference. In the case of wheel covers, maybe this is a practical demonstration of The Pareto Principle

I bought a set of stainless steel covers (AKA "hubcaps") at The Wheel Pros for $250.95, including GST.  Here is a picture with the old covers on top, and the shiny new ones on the bottom.

On my rims, the lug nuts have to fit inside the lug caps on the  wheel cover. It is a tight fit and if they aren't centred correctly, you can damage the lug caps.  You can't see the lugs under the wheel cover, so it is easy to be off-centre.  

The lug is off centre.
One method is to remove one lug cover so that you can make sure everything is centred as you install the wheel cover (as in the picture below).  Notice I am using a rubber mallet so I don't damage the wheel cover.
Hammer the cover onto the rim with a rubber mallet.
The problem with that approach is that the lug covers may become loose if you repeatedly remove and replace them.

Here is a better method I'll try next time, but it will require a little more care.  Look for the valve through one of the holes around the outside of the wheel cover. When the lugs are properly centred, the valve will also be centred in the hole.  Keep the valve lined up as you hammer the cover into place
Valve is centred in the hole. 

Post Script: 
Before you install hubcaps on your truck or motorhome, you might want to read a more recent post as a bit of a cautionary tale (click here).