240D Air Con question
 

My little 240 D lets me know when the AC is on... it's like when I turn it on she say's " your gonna regret this on the next hill"...... but she does oK...sorta!

Here is my problem..The original and previous owner spent $1700 on a new AC system put in by German Motors in Las Vegas (last September). I purchased the car in Feb after it took a very light front minor fender hit... BTW, that did not affect the AC.
It just does not feel like it blows real cold on a 92* day. It does get cool but not cold...feels like it's coming out about 55+* at the center vents.
It has R134a in the system... what should it be at the vent using thermometer? Should I top it off with a can of r134A.
Not gonnna go to a shop or dealer cause it 's not that bad... just need a guide of where to start. I'm a AC novice but a good/willing learner and would like to learn from the board. I'd like to preform my own work.

thanks

Do NOT "top off" a 134 converted system without monitoring high side pressure. The high side can easily run away which could cause system damage.

If it were mine I would reverse convert. These a/c's just are too marginal in capacity to get the job done with 134. By putting on a larger, parallel flow condensor they can be made to cool decent with 134, but this is economically unfeasible. With R12 prices going down and 134 prices going up, it makes no sense.

Good luck,

Not to hijack, but R134A pricing is on the way down now. That doesn't in any way mean I disagree with Larry and the others about R12 vs. R134A, just had a discussion with someone about it a couple of days ago about the price coming back down.

As an inferior molecule for the purposes being discussed... it OUGHT to come down in price... it ought to be free... then people would realize what it was really worth.... nothing....

Bennett, buy a $5 pencil thermomoter with a dial top on it and find out what it is actually blowing at the vent... then look at the charts for ambient temperatures and see if you think you really have a problem... then consider getting the guages and change it back to R12 if you really want it cooler...

If I was to go through the trouble of installing a parallel flow condensor, it would be to improve on the R12 system. Even with R12 and everything working properly, the 300D A/C just isn't adequate for Louisiana in August. Convert it to R134a? I may as well just roll the windows down and save the fuel that the A/C would be using :P

Unfortunately even that option is not available for most cars... the cars are designed to run with the windows up.... and having them down creates a lot more drag... so you might be hot and not even saving that gas used to run the AC... talk about adding insult to injury...

I've had several 240D's and have been in Houston and New Orleans with every one of them during the Summer. I never had any problem keeping cool in them. One of them even had an aftermarket a/c (Euro car) and it worked fine as well.

If your 240D a/c, still on R12 won't cut in Nawlins then it probably needs a little attention.

Good luck,

Warning: Hijacking in Progress!
 

I just recently got my 609 certification and added some freon to the 300D this weekend. It took about 10 ounces before the pressures looked about right (perhaps a tiny bit undercharged, to be on the safe side). This will be my third summer with the car, and maybe this time around it will be cooler. I also did the "100% recirculated air, all the time" mod when I went through the vacuum system last month, so that should help a bit too. Last summer the A/C woked fine until the amient temperature got into the lower 90s. My '93 T-Bird, on the other hand, will freeze you in any weather. I only use the maximum position to cool the car off, then I switch it to normal. I have yet to see weather so hot that max A/C won't make the car too cold. It has about the same capacity system as the 300D (both R12), but the condesor is a probably 50% larger.

FYI, here are the numbers after I topped it off:
ambient temp: 90 F
humidity: 70%
engine rpms: 1500
high side: 240psi
low side: 28psi
center vent temp: 48-50 F

What is needed to go to R12?... I already have a 50lb tank of R12 I bought 3 years ago for a good deal.
Do I need to "evacuate" the system , add oil or new o rings etc?

There is a huge amount of information on this in the archives...the search feature works well....maybe too well... but this has been posted multiple times.... each and every facet has been gone into in depth... often with a few non believers egging us on...