Hyundai Santa Fe Air Conditioning Troubleshooting

We live in Arizona and needless to say, during the summer it tends to get a little warm; it's a dry heat they say. Whatever... it's hot!

My wife had been complaining that the A/C in "her" car, a 2005 Hyundai Santa Fe, didn't seem to be working as well as it used to. I figured it probably needed a recharge and all would be well again.

Well, we didn't have a chance to get it in the shop before we left on our trip to Flagstaff for the 4th of July weekend but we figured it'd be okay until we got back. Wouldn't you know it though shortly after we started out, the A/C wasn't working very well at all. It worked reasonably well if we were traveling 40 mph or more but when we slowed down or stopped, it started blowing warm air.

I-17 between Phoenix and Flagstaff can be very busy during holiday weekends and the chances of getting stuck in a traffic jam are pretty high. Before we got very far, we decided to go back home, transfer everything from the Santa Fe to our truck and use that for the weekend. We'd worry about he A/C when we get back.

The weekend went well and we had a lot of fun but the weekend came to an end and as usual the hand of reality slapped us into the first day of the work week. So...that meant I had to do something about the A/C. I took it to a shop, they checked out the A/C and told me everything was working well except that it was .5 lbs low on refrigerant. The system capacity is 1.3 lbs. so .5 lbs low is significant. For $160 and some pocket change they evacuated the system to get out all the air and water and refilled with refrigerant, oil, and a dye to help find future leaks.

It worked better after that but it still wasn't 100%. At stop lights, it would still blow warm air. Once we got moving again, it would blow cool air again after a couple minutes. Well, apparently everything was NOT working well.

I'm not a professional mechanic but I'm pretty handy. I do most of the maintenance and repair on our cars, home, appliances, etc. Although I have almost zero experience with A/C, I decided to look at it myself. Five minutes of research on the Internet revealed that the most common reason for A/C blowing warm air at idle is a condenser fan that's not working.

It took some looking to find the condenser and condenser fan. The condenser is located in front of the radiator on the driver's side, the fan is located behind the radiator. The condenser looks similar to a small radiator.

I started the car, turned on the A/C and never saw the fan run. That made me wonder why the engine didn't overheat. More research revealed that there is also a fan located in front of the radiator on the passenger side; this is the radiator fan. This one was running.

WARNING: Both fans are electric. On some cars these fans can start at any time, even when the car is turned off, so keep your fingers and anything else you value away from them. Disconnect the battery or the fan connector if you need to work directly on the fan.

More Internet research was done to find out what could cause the fan not to run. Most of what I found was related to fuses under the dash, and fuses, fusible links, and relays under the hood. The first thing I decided to check was voltage at the fan. If there's voltage at the fan that pretty much narrows it down to a bad fan.

I could't get the fan connector apart so I checked voltage by sticking two pins in the wires of the fan harness. No voltage. Checked all fuses, fusible links, and relays and all tested good. Pulled the connector off of the temp sensor which should start the fan if everything else is good. No go, the fan just sat there. Now I was stumped, not much else except wiring and the thought of troubleshooting that didn't appeal to me at all.

It bothered me that the fan connector wouldn't come apart so I decided to get that apart even if I broke it in the process. I figured if it breaks, I'll splice it. I pried one side with a screwdriver and heard a slight snap. Did the same to the other side and also heard a snap. After that, it slid apart easily.

I checked voltage at the supply side of the connector and read 12 volts. Now I'm getting somewhere! I have voltage on one side of the connector but not the other? Further inspection revealed that the inside of the plug was melted; possibly due to a bad connection that caused excessive resistance.

Put current through resistance and it creates heat. Put enough current through enough resistance and it creates too much heat. Many plastics don't like heat. From that mumbo jumbo you'd never know that I have a degree in electronics but I don't want people dozing off before they finish reading.

I removed the condenser fan relay so that no power would be at the connector. Then I cut the leads off of both sides of the connector and bought some weatherproof crimp butt connectors from Checker. With the power disconnected, it's a good time to check the fan to make sure it turns freely. It did.

I spliced the now connector-less wires with the butt conectors. Bingo! The fan worked. I let it idle for 10 to 15 minutes and the condenser fan ran continuously and the A/C blew cold the entire time. Then I wrapped it tight with electrical tape and zip-tied it to the bracket where the connector was located.

Nowhere on the Internet did I see this connector mentioned as a possible problem. The outside of it looked fine, it was just the inside that was melted.

I learned a long time ago that when troubleshooting, never say, "That can't be the problem." Always entertain all possibilites from the complex to the extremely simple. In this case it was a simple component that is not generally prone to fail but...it did.