91 Accord Air Conditioning Issues
 

I'm certain this has been addressed before, but here goes:


My girlfriend is out of the country and I decided to surprise her by repairing her air conditioning in her '91 Honda Accord. It had the usual symptom: blowing hot air.


So I started my troubleshooting:


First, I did the simple thing: tried to charge it. This system was converted some time ago by someone else, so I suspected a leak. The moment I cracked the can open, it had a massive leak!


Next: replaced O-rings on compressor side and tried to replace the manifold formed O-ring. Big mistake! Stripped the head of a bolt and ending up replacing the compressor. So O-rings replaced, compressor replaced, and try it again. Nope! Still have massive leak! Digging deeper.


Found the condenser completely shot! Replaced condenser. Try it again. Whoopee!! It takes refrigerant! But it's not cooling. Just noticed, the condenser fan is not coming on. Checked relays. All good. Checked fan. Motor is shorted. So replace condenser fan. Check the charge. Charge has about 32 ozs of R-134a in it (give or take).


System is blowing cooler than outside (97 degrees outside), but still not doing as well as my other R-12 converted vehicle.


So I let it run for a while.


No noises. No strange sounds, condenser fan runs fine, it just isn't getting as cool as it should. This is a major jump from before when it blew HOTTTT air, but still not right.


Holy Melting Humans, Batman! What now?

How are you measuring the amount of R-134a in the system? How much R12 is listed on the sticker under the hood?

The sticker reads 32 oz. R-12. I am measuring the pressure with a set of gauges. Low Side reads about 45 psi. The gauges are cheap and the High Side blew a hose, so I'm relying on low side readings. I installed a 22 oz. can of R-134a with dye, a 12oz can with sealant and watched my gauge as I topped off with a third 12 oz. can. I did not empty the can. The Low Side line coming off the firewall has a little sweat, but again, not as much as I would expect. I'm missing something simple. Also, it's 97 degrees outside and about 125 inside the car, per my digital temp gauge. Humidity is about 37%.

I'm missing something simple. Have to be.

You will need to read the high side pressure to see what is going on in the system.

Is the compressor clutch running the whole time?

I also think you are overcharged. The rule of thumb is to charge 85-90% R134a relative to R12, so you should only need to add about 27 oz.

The clutch is running the entire time. The condenser fan is running also.

I was not aware of the difference is capacity when substituting R-134a for R-12.

I believe you are correct. The system is probably overcharged.

I'll get my gauges fixed and check the system.

Thank you.

Since the system is overcharged, I'd disconnect the electrical connector to the compressor and secure it with a zip-tie, so you don't run the risk of having something pop in the system.

I took it to a friends shop. He vacuumed it down, leak checked it, and charged it. Still no cool. He further troubleshooted the system. You are not going to believe what he found! Would you believe a broken temperature control knob? It wasn't able to go to the full cold setting!

It did need a condenser and condenser fan, but a broken knob? Just goes to show the simple stuff is sometimes the solution!

I'm glad it was something simple after all the work you did to get the system to hold a charge.

Thanks for posting the fix and result.