The Shop Truck #1 — Air Conditioning Repair


Welcome to the first installment of “The Shop Truck.” In this ongoing series that signals the launch of Blast Cars, we are repairing and restoring a 1987 Dodge W150 Power Ram pickup truck that we found on Craigslist after a long and painful search, lots of negotiating, and one near-scam involving a request for a Western Union down payment!

After looking at Chevy/GMC, Ford, Dodge, a Jeep Comanche, and even one International, we decided to purchase a Dodge because there are fewer of them out there, and I honestly love the classic look, right down to the hood ornament. (Forget that I’m a Mopar driver for a second, I swear that we gave every brand a fair shake!)

Shop Truck Entry #2 will delve deeply into the shopping experience, so stay tuned.

Here’s what she looked like on the night we took delivery:


There is some body rust. The driver’s side floorboard is rotted. The stereo, air conditioning, wipers, wiper fluid sprayers, power windows, and locks don’t work. It shifts hard into reverse and out of 4WD, but it DOES shift. Oh, and it stalls when idling sometimes. The exhaust probably has to be replaced also. We’ll go through each section piece-by-piece, starting with today’s entry.

We did luck out that the truck is pretty much bone-stock. It’s been sitting for a while, but nothing has been done to the truck that would raise any alarms. No homemade lift kits, either!

Why a 1980s truck? Doesn’t everyone restore 1940s-1960s trucks? Sure, but Blast readers are 80s kids, and we remember the sights, sounds, and smells of 80s cars and trucks.

So we have some work to do. Let’s get started.

The Shop Truck #1 — Air Conditioning Repair

One of the most common question marks that pops up when buying an old car or truck — does the air conditioning work? If you turn on the A/C and cold air comes out, you’re already ahead of the curve. But if warm air comes out, don’t panic just yet.

The latter was the case when we purchased The Shop Truck. The fan spun — air came out — but it wasn’t cold.

Now, as you’ll read in a second, we got lucky. But a broken air conditioner is a big red flag when buying a used car. (We know — If you’re building a racer or a car that’s purely for show, you might be ripping the whole unit out anyway to save money and weight. If you’re driving the car like we are, pay attention.)

An Air Conditioning System (Courtesy of Padonia Auto Service)

An Air Conditioning System (Courtesy of Padonia Auto Service)

Quick tech: Your car’s A/C is basically the same system that cools your house, only smaller. It is chiefly made up of a chemical called refrigerant that carries heat away, a compressor, which circulates the refrigerant into the system, a condenser which expels the heat removed from the car, and an evaporator, which transfers heat to the refrigerant. Essentially, air gets pumped into the system, the system sucks the heat out of the air, and the cold air product gets blown back at you. Strictly speaking, the system doesn’t “cool” the air; it removes heat from the air, but that’s way too much physics for one day. Click here and here for more technical info.

Older cars like this used R-12 “Freon” as refrigerant, which is banned today because it is one of the most dangerous chemicals to the Ozone that we have as-of-yet created. Today’s air conditioners use R-134a, which is slightly less destructive, but remains the only effective refrigerant that isn’t flammable or otherwise deadly to humans. To convert from R-12 to R-134a, you have to buy a Retrofit kit, like the one made by Interdynamics. Big warning here: Follow the directions. Don’t just put R-134a into an old air conditioner. It doesn’t mix well with R-12 and will ruin your system.

We did get lucky. The Shop Truck had already been given a proper Retrofit. Kevin, our truck guru from Associated Equipment Service in the Hyde Park section of Boston, did a leak test and recharged the R-134a coolant, and the air conditioning immediately worked perfectly. We were both pleasantly shocked.

Of course, we can’t end there. “We got lucky, the end.”

What if the system was busted? Bad Retrofit? Blown compressor?

Four Seasons Air Conditioning Compressor

Four Seasons Air Conditioning Compressor

Here is what you should expect to pay for whatever various parts you need:

Now, we don’t have any serious sponsors yet, so you can trust me when I say that I like the Four Seasons brand for OE replacement HVAC parts. They tend to be cheaper than the more familiar ACDelco brand, though both are cheaper and easier to find than the original Mopar parts. Of course, if you have a Toyota, go with Denso.

Fixing a system or installing new parts can be done at home, but it is probably a solid 6 on the 1-10 scale, with 10 being the hardest. Your local auto store will sell you a fluorescent dye you can add to the system to check for leaks. Don’t puncture any of the lines — it’s illegal to vent refrigerant into the air. A non-working A/C can be as simple as a blown fuse preventing the compressor from kicking in, so don’t go out and buy every part just yet. Huge tip to remember — never connect coolant cans to the red or “high pressure” side of the system. It could cause the can to explode.

OK, so Air Conditioning isn’t as exciting as the engine, exhaust, or the broken stereo we’ll get to fix. It gets better, I promise!