Hot Baby

My wife drives a 2003 Altima. It only has about 60,000 miles on it. It is in great shape. The only problem is occasionally, on VERY hot days, the A/C decides to stop working. She has had it in the shop a few times, but they could never properly diagnose it. I am used to driving vehicles with parts falling off, so this seems very minor to me. The A/C in my truck hasn’t worked in years. You just roll down the windows and tough it out.

The problem is that now we have an 11 week old baby. We don’t want to risk putting the baby in a car that could at any moment turn into an oven of death. It happened once and the baby turned all red. It scared my wife.

Where do we go from here? We like the Altima. It seems silly to get rid of it because of such a minor, intermittent problem. But if nobody can fix it with any level of confidence, I don’t see many options. Summer is coming!

If, “the shop”, that failed to diagnose and fix the A/C problem is a garden-variety repair facility, or even a dealership, I am not surprised. You need to look in the Yellow Pages for a shop that does just auto A/C repair. A shop like that is almost always able to figure out A/C problems that stump an everyday mechanic.

I tried googling it. I don’t think anybody really specializes in A/C in New Jersey. They’d have no business for half the year.

When the AC stops working, stop and open the hood and see if both fans are working. Also check your temperature gauge and see if it is abnormally high, anything higher than you normally see on a cooler day.

I can try that. Is there any way to trick it? Maybe a strategically placed heat gun or hair dryer?

"I tried googling it. I don't think anybody really specializes in A/C in New Jersey. "

I don’t think Google is necessarily the best way to find everything. In this case, the phone book yellow pages might be more useful, it certainly is here, and I’m not in a city. However, the best auto A/C guy in town, 40+ years experience, can’t be found that way. But he’s well known anyway, works out of a fully equipped shop at his house. The mechanics all know him, and that’s who you should ask.

"I can try that. Is there any way to trick it? Maybe a strategically placed heat gun or hair dryer?"

No just wait until the AC stops working, then open the hood. actually the fans should be working anytime the AC is selected, whether it is hot or cold outside or even if the engine is stone cold. If they are, then check again when the AC stops working to make sure they are both still working.

Checking the engine temp gauge on the dashboard when the AC stops should also be pretty easy to do. If it is higher than normal, that would be a clue to the problem. Don’t try to trick it.

The hardest thing for a mechanic to figure out is something that happens intermittently. Your mechanic knows that you do not want to be paying him his hourly rate, which in New Jersey is the highest in the nation, just to drive around for hours waiting for the problem to reappear. You can help him, and save yourself some money, by observing and checking a couple simple things when the problem does occur. Checking the fans and the coolant temperature gauge are two things you can do yourself very quickly, even if you don’t have a lot of automotive repair knowledge yourself.

One more thing you can quickly check, is the blower motor fan working. Put it on the highest setting to check, then check all positions. If the blower motor quits working, the AC shuts off. If it works in the highest position but none of the others, that is another clue that will guide your mechanic to the right place.

“I don’t think anybody really specializes in A/C in New Jersey. They’d have no business for half the year.”

I live in NJ, so I can tell you that you are incorrect.

A check of my local yellow pages shows at least 5 auto A/C specialists in Central NJ (Middlesex & Somerset Counties). Many of the auto A/C specialists are also specialized in radiator repair, so you might want to look under radiator repair, as well as auto A/C repair.

I finally got to witness the A/C failure first hand. It was working fine for a few miles and then it just started blowing warm air. I stopped and picked up some toilet paper. When I started the car, the A/C was working for a few seconds, then it went back to blowing warm air. I pulled in a parking lot and popped the hood while the engine was running. There are two fans and they turned on and off in unison. They’d run for a little while and then they’d both turn off for a while. The compressor wasn’t doing anything. I remember reading somewhere that there is some kind of sensor behind the glove box. I tried to figure that out, but I didn’t have tools or a manual and I didn’t want to break anything. My wife does pack her glove box pretty full, though! Could that be blocking air flow? I shut the car off for a little bit. When I started it back up, the A/C was fine for the rest of the day.

All the functions of the AC system are controlled thru the Intelligent Power Distribution Module. This module includes the relays for the cooling fans, the relay for the compressor, and includes a Central Processing Unit which controls these relays. The CPU also receives signals from other sensors in the vehicle to determine when the AC should function or not.

If the AC works fine sometimes and then doesn’t, I’d suspect a problem with the IPD module.


There should also be a pressure switch in the AC line that will prevent the compressor from running if the freon charge is getting low or the switch itself can be faulty.