a/c button does not light up or turn on the a/c...

[nyc525iTe34]

Hello everyone,

Hope that someone can offer some sagely advice or point me in the right direction here.

Car: 1993 525iTa E34
Problem: a/c does not turn on

Description of problem

When I push my a/c button it does not light or turn the a/c on. Nor does the circulation button light up. The rear defroster button does light up and works perfectly (as does the fan blower at all speeds). I get excellent heat. All three buttons are below my radio to the far left side. Today was a very nice day - 75 degrees.

Any thoughts on what gremlins could be causing this issue?

[genphreak]

Usually the system pressure is too low so the safety switch prevents the compressor trying to compress something it can't. Common issue, seals go. Best to have the compressor rebbuilt at least once in the car's life.

Try just having a regas and new dryer/filter done first- that will do it for a little while, maybe longer :)

The above assumes the fan blower is on and working when you activate the AC, and that the small AC belt is intact and working of course.

[nyc525iTe34]

Usually the system pressure is too low so the safety switch prevents the compressor trying to compress something it can't. Common issue, seals go. Best to have the compressor rebbuilt at least once in the car's life.

Try just having a regas and new dryer/filter done first- that will do it for a little while, maybe longer :)

The above assumes the fan blower is on and working when you activate the AC, and that the small AC belt is intact and working of course.

Many thanks for the quick and sound advice. Anytime one mentions the word "rebuild" my wallet shakes...lols

Any idea what a "regas" and new "dryer/filter" might run these days and whether this issue is best left to be resolved by a specialist or can any normal mom & pop garage that deals with a/c handle this task? Also, the "dryer/filter" ...is this a receiver dryer?

I'm in NYC...

[genphreak]

Many thanks for the quick and sound advice. Anytime one mentions the word "rebuild" my wallet shakes...lols

Any idea what a "regas" and new "dryer/filter" might run these days and whether this issue is best left to be resolved by a specialist or can any normal mom & pop garage that deals with a/c handle this task? Also, the "dryer/filter" ...is this a receiver dryer?

I'm in NYC... You need someone practical that knows BMWs and doesn't overcharge but doesn't screw it up. That's what costs you money with a BMW (and many other cars too).

If you cannot find someone local, ask the local dealer. They won't usually overcharge on an older car, but they will get it right. Oftentimes, they just tell you to go see the right local indie down the road that know what they are doing. The stealer makes it's daily bread working on new ones where the cusotmers have deep(er) pockets. Poke around on bimmerforums.com or search here for indie indies nyc "new york" and combinations thereof...bmwe34.net is worth checking out too.

A dryer can be had form www.bmaparts.com (http://www.bmaparts.com) for a very little. Jst give them your VIN and it'll find the right one. Must get these form a good source, they have to be sealed up unto the moment they are installed as teh carbon filter dies if they are left open to the atmosphere.

Maybe someone local to you will chime in and let you know where to go.

[Tiger]

Usually a shop will charge $150 to evacuate your system... check for any leakage and replenish refrigerant and oil.

What you really want is someone with computerized AC recharge machine... don't trust someone with old vacuum gauge machine. Only the very knowledgeble folks would know how to use that kind of machine but face it, most mechanic are not very careful with recharge weight.

[genphreak]

Many thanks for the quick and sound advice. Anytime one mentions the word "rebuild" my wallet shakes...lols

Any idea what a "regas" and new "dryer/filter" might run these days and whether this issue is best left to be resolved by a specialist or can any normal mom & pop garage that deals with a/c handle this task? Also, the "dryer/filter" ...is this a receiver dryer?

I'm in NYC...You do have the fan running when you press the AC button tho, right? I'm not sure, but if the fan speed you've got selected is failing to run the fan, this may stop the AC light coming on....

[nyc525iTe34]

Thanks again to everyone who replied to this post and offered advice.

I am going to order a pressure kit that a friend of mine told me about that will offer a quick-fix (hopefully until summer ends) which will cost about $50. My friend is pretty knowledgeable on BMW maintenance so he's going to assist me with the process.

Thanks again! What a great forum!

[nyc525iTe34]

You do have the fan running when you press the AC button tho, right? I'm not sure, but if the fan speed you've got selected is failing to run the fan, this may stop the AC light coming on....

Yeppers, the fan is running with no issues whatsoever.

[genphreak]

Yeppers, the fan is running with no issues whatsoever.Cool. If the pressure is down, it will need a new drier. That means evac and fill. Your recharge kit will work, but it isn't kind. The drier can end up saturated and cause corosion inside the system in the long run causing compressor failure that cannot be repaired. You can alwasy nuy a new compy, but it isn't necessarily the best course of action.

[KenB]

I have the same issue and has happened before. I have had to add freon to the system every 2 years, I guess there is a VERY slow leak somewhere but by now I'm sure it is time to replace the Receiver Drier/Accumulator. Behr part available from Autohausaz.com for around $35.

[Tiger]

No need to change any drier unless you cracked open the system. So don't just change the drier alone... inject some dye along with your freon to find the leak.

If your system is not cold but pressure is up there, you definitely have to vacuum entire system and recharge.

[nyc525iTe34]

Just wanted to provide closure on this thread for all of you great guys who helped me with your sound advice....

I decided to go the inexpensive route and ended up picking up a couple bottles of r134 freon from my local auto store (Autozone). They sell the freon recharge kits for about $49 (Quest) or you can buy one 18oz bottle of freon for about $22 (includes attachment hose and pressure gauge).

I simply attached the recharge kit to the low pressure a/c valve and it took less then 1 can (18oz) to get turn the a/c back on and running cold.

The instructions on how to do this recharge are clearly labeled on the recharge kit - doing this was a BREEZE.

Now I know that this is most likely a temporary fix but if this can keep me through the summer I will be psyched! The car is icy cold and the a/c is running smooth.

Always turn on the a/c at least once a week during the winter along with the defrost for a couple of minutes so as to keep everything lubed up and ready to go come summer.

Thanks again to everyone!

[Tiger]

It will hold, it doesn't take much to loose AC... and you can keep doing this. Most recharge has some kind of light sealer... will plug up minor leaks.

Easy huh? LOL