2003 Saturn L300 AC will not turn on!!!

I posted a reply to you on another users question posted on to start your own question before I saw this one.Anyway you can snap a pic of your climate control display? I may have an idea of whats going on here.Also with a auto climate ac it makes it much harder for a diyer to diagnose.There is a computer in your ac control head that requires a professional scan tool to read codes in it see data inputs in it etc.The diyer scan tools can't do that.

Do you want the snap shot with the control head on, lit up or off? How do I get to the other reply you wrote for the other user's posted question?

They keep changing everything on this site so its hardto keep track of searches eetc.I know you can select Saturn or cars models and search by ac.I would like a pic of the control head screen all lit up with the display on.So I can see what it looks like.

Here is the control head. The back lighting went out after I switched out the head with a used one from LKQ which turned out to be bad as well. It may not be apparent but there are 2 missing bars on the LCD digit display. Also the pic you see is what it defaults to 5 sec after messing with the controls. Does not make any sense to me (-19 degrees???). I have ordered another control head from LKQ arriving tomorrow. Hope it is a good one that works.

Do you have any idea about repairing the circuitry on the board inside the control head?

Thanks so much for your interest!
Abel

Now were getting somewhere that's why I wanted to see the LCD display.You see how it says -19 then below it says ext?That means it thinks outside temp is -19 so it won't allow the ac to work. There is a outside. Temp sensor for the ac in the front grill area towards the center.See if its plugged in and the wires too it are good?I have seen this before that's why I wanted to see a pic of the ac display.

Oh wow! Ok i will certainly look in the AM. I know this car front end was hit because the condensor had a hole in one corner where the bracket was busted holding it to the radiator. Have also noticed 2 loose wires dangling near the bottom of the right fender, if I remember correctly. Both fender wells are missing the splash shields and plastic barriers covering the bottom side of the engine bay.

Thanks for the insight!!! Will let you know tomorrow after work.

Sounds like a wire issue from your description

No sensor on the grill anywhere. 2 wire connector (purple and black wires) hanging down near driver side fog light hole (also missing) Is that the sensor connector?

Also how to fix the back lighting on the control head?

Have you looked below the grill in the bumper opening?Not sure what the colors of the wires are will have to look them up.Let's worry about the back light after we get the ac working

The wire colors are light blue and the other wire is black.It shows the sensor over by the left head light area by your cooling fan relay box.I guess I was wrong the earlier cars were in the grill area.Let me know what you find.

Found the bare yellow/black wires which are not attached to a connector hanging down on driver side below & behind bumper. [The purple/black wires are for the fog lights.] Without a pic to show how the wires feed into the connector, how do I know which side to connect the yellow wire to on the temp sensor? Should have a new temp sensor in hand tomorrow after work. I don't want to mess up the sensor by connecting the hot wire to the wrong side.
Thanks so much for your interest.

In my wire diagram I see light blue wire and a black wire unless there that color I would say my wire diagram is wrong or you found the wrong wires.

In the 2002-2003 Saturn HVAC service manual the schematic shows a Lt Blu wire out of the Control Head but for 2003 year only, apparently that wire splices with a yellow wire before ending in the connector.

If that's the Saturn service manual we will go with that one.Terminal B is the black wire.Also the yellow wire is terminal A.

How to tell which pin in the sensor goes with the yellow wire or black? The connector is gone - just bare wires hanging down. Does it matter if I reverse the connections?

You need to buy a new connector an the terminals on the connector labeled A and B.I will look for a connector for you.

Rock auto.com has re connector you will have to the oic to your swsor they show two different ones.

I shorted the 2 bare wires and the ext temp read 140 and the compressor kicked in!!!!!!!! Haaaaaallelujah!!!!
Now does it matter if I reverse the wires to the ambient air sensor? I don't want to damage it!

Sorry didn't see your answer about the connector being labelled. Actually had it in my shopping cart at rockauto since last night. So will go ahead and get it now.

Now, the compressor runs fine but the low side pressures jump up to almost 100 when I try to charge the system. It has less than 10 oz of R134a in it presently. High side will not rise above 140. When I shut of the flow of refrigerant into the low side, the low side comes down to 30-35 but no lower, even if I rev up to 2000 rpms. Revving does not change the high side at all; the needle seems to waver a bit actually. I do not believe any refrigerant is actually flowing into the system with the valve open (can does not get cold) due to the almost 100 low side pressures that won't come down with revving.

So is my compressor done for? It seems that it cannot compress good enuf to lower the low side and raise the high side. What is your opinion?

When you open the can your measuring the pressure in the can at that point.So of course the pressure will use to 100 or ore on he low side .What I do is charge it with he ac off till it wont take anymore. Then turn the ac and put the rest in till its completely charged. Some cars hard to change with thisse 12 oz cans.Till you get it fully charged I wouldn't be looking too had at the pressures and saying this or that is bad.

Will give it another go at charging. Will leave if off and see if refrigerant will flow in. Have charged several cars and never had it climb to 100 and stay there with compressor running. Will always come down when engine is revved up. So what if the can never gets cold - and is not empty? Does that mean nothing more will go into the system?

Really do appreciate your assistance!!! I paid a car electric guy who specialized in AC system, whom I was referred to by the car AC specialists in town, and wasted my $75. He didn't even mention the ambient air sensor! You rock, man!

Are you turning the can while charging or just leaving it straight up?

straight up. Pressures usually climb higher temporarily when tipped over and the liquid refrigerant flows in.

When using those 12 oz cans to charge you go from 12 o'clock to 3 o'clock every 15 seconds.

I have done it both as you say and just leaving it straight up. With a normal compressor, the can empties faster doing as you say which is what the instructions say on the can. I was cautioned by an expert that compressors are not meant to handle a liquid slug so I only turn it sideways if I get impatient. Anyway, with this compressor, it doesn't matter what I do with the can, it will not charge the system. Have a compressor on order as well.

So any ideas what to do with the backlighting issue? Can it be repaired? I thought of using a strip LED to illuminate the face of the display.

I have never seen a bad compressor cause the ac not to allow it not to take a full charge.Also did you pull a vacuum before charging the system?I have never had a back light issue on those.Is a twist in blub in the back of the contolr head?

I did pull a vacuum. It held overnight. The a/c experts in town here said it was a bad valve in the compressor if the low side pressure will not come down.

Will look at the control head closely tomorrow

You said your low side went down to 30-35 psi without the flow of charge going in.That's not a bad pressure.I have never seen a bad compressor cause the ac to not take a charge on those cars an have worked on them since they came out in 2000.The pressure will read 100psi because its reading the pressure of the charge in the can when you open the flow from the can.The experts also couldn't figure out the reason the compressor wasn't coming was because you were missing the outside air temp and connector.So don't know how much faith to have in them.I have had trouble charging charging some cars and had to make several attempts to charge them.

Okay! Figured out why low side pressures so high - the low side pressure gauge is not working!!! Pressure being trapped within somewhere keeping pressures up. This manifold set is almost 20 years old!!! So maybe compressor is fine. Will get new gauges tomorrow. HBF has set for $40 with a coupon. Hope its decent. Wow, will be wonderful not to have to change the compressor and do all that work!

I bought the harbor freight ones a few years back and ave used them for a couple of years now.They work OK I would by the 2yr extended warranty they only have a 90 day warranty.

Now, for the conclusion of the A/C repair saga --- installed a ambient temp sensor and problem solved! Compressor works just fine. It was my low pressure gauge that was malfunctioning. So replaced it with the set from HFT and charged up just fine. Low side stays around 28 - 35, High side gets to 300, then condensor fan kicks in and drops back to 250 or so. Inside temp down to 45 degree with ambient temp at 90. Mr saturntech9, my hat is tipped to you!!! You saved the day and saved me $.

One last question - how do i find a replacement bulb for the LED back light? See pic. Where to find? Can I use something else?

Have a good weekend!!!

Your welcome once again those ac experts were wrong about the ac compressor.Glad to hear the ambient temp sensor fixed it like I thought it would.As far as the bulb goes I looked at of a couple of places I find hard to get parts no listing.Is there a number on the bulb or bulb holder?

I will look closer again later - already put it back together.

Just a word to others that may be following this discussion -- i connected the wires of the ambient temp sensor backwards before I saw the very very tiny "A" and "B" on the connector. There is nothing marked on the sensor end itself. I thot I killed the sensor coz it quit reading the temp. I put the sensor back in the box thinking it was dead. But 12 hrs later I reconnected it just to see if it would work again and sure enuf, it worked fine. So maybe the thermistor just needed time to cool down or reset or something after applying voltage to the wrong end.

I told you the connector was marked A AND B lol.Lookagain on the bulb its eeasy to pull.

Only thing I see on bulb is "S" and a very tiny "3". I found some orange LED's that might work on Radioshack.com for less than a dollar each but the shipping is $8.99! May have to just get those LED's unless you have another idea.

Try have a T as the base of the bulb size so the bulb number maybe a S3 let me look around.