I am new to Hondas but not to auto repair.

I have a '93 Accord with dead AC. I'm told it was working last fall, but not blowing very cold. So I suspect it has been leaking down over time.

I believe this is an R12 system (the car is not here but I'll check the fittings).

My questions:

1. Am I better off scrounging up some R12 or convert the system to R134a? (What about Freeze 12?)

2. Nothing at all happens when the AC button is pressed. Fans do not come on. Compressor does not engage. In fact the lite on the dash button itself does not even come on. (What in particular, if anything, does this suggest?) The fuse in the drivers side kick panel is good.

3. I'll start shopping now for a good R134a manifold gauge set in anticipation. (Or can I flush out/clean my old R12 gauges and use them with fitting adapters?)

Many thanks in advance for any help you experts can lend me.

 

I can't remember what year the accord when to R134a. It was around 93. There is a sticker under you hood that should tell you if it is R12 or R134a.

When diagnosing the a/c, I would start by testing at the pressure switch. This is plugged into a hard line near the compressor and has 2 wires going to it. The colors are blu/blk and blu/yel.

Grab a volt meter. With the key in the II position and the a/c switch turned on inside the car with the blower turned on. Unplug the pressure switch. The blu/blk wire should have 12V. The blu/yel wire should have continuity to ground (closed circuit or ~zero resistance). Also the two pins across the pressure switch should have continuity to each other.

Let us know what you find.

 

Thanks for the reply PAhonda.

The system is R12, with Schraeder valve ports - and I also located the R12 ID sticker on the passenger side fender.

I found the pressure switch. Unfortunately at some point in this car's history it apparently got smashed somehow. There was black electrician's tape wrapped loosely around the exposed wires.

I peeled the tape away and could see corrosion has taken hold. In the course of doing this, my moving the wires around connected a formerly broken connection apparently. The fans came on and the dash lite was now lit.

So I started the engine and the compressor kicked on. It cools, but barely. Very weak.

I'll have to decide what to do about the pressure switch connector.



What are your thoughts at this point?

 

Well, the wiring at the pressure switch is a problem, so you will need to correct it before moving forward.

There are a few ways to tackle this problem.

Find a wrecked 90-93 accord at a u-pull it junkyard and cut out that portion of the wiring harness. Then splice and solder into your existing wiring harness.

You can release pins from an electrical connector. Then trace back where the damage is located, splice the existing wiring harness, then solder.

Sort of the same solution, replace or repair the wiring is where to start.

 

I agree. Gotta fix the wiring.

Is there an image somewhere of what the intact connector looks like? I'm wondering if the same style connector was used on R134a systems.

 

Honda does not sell individual connectors to my knowledge. That leaves used as only option. Suggest trying car-part.com to locate a used parts outlet near you w/ 90-93 Accord that may offer a donor part. You may have trouble just buying this part anywhere except a U-pull-it yard. Parts yards just don't seem to have interest in small parts. I don't know if later model pressure switch connectors were compatible.

Regarding rebuilding your system. I would suggest retrofitting to R134a for easy access to refrigerant and similar performance. You need to pull the evaporator to replace orings around the expansion valve and thermal feed-back bulb. They leak w/ age. Expansion valve should be replaced w/ one tuned for R134a. Pulling evaporator housing is not too difficult, but shop manual is essential.

ackits.com can be a good source for DE PAG, quality 134a fittings, new R134a expansion valve, compressor shaft seal if needed, etc.

Download one of the manuals via the Online Manuals links in DIY forum.

good luck

 

Hey Tex thanks for the input.

I went to my local salvage yard today and found a nice replacement connector. It was about the only worthwhile thing left on the poor car - man was it picked clean. In any case, that issue is solved.

I agree that converting to R143a is the thing to do in the long run. But this isn't my car. I'm helping out a friend, and the priorities are going to be: 1) How quickly can the AC be fixed?; and 2) How inexpensively can the AC be fixed?

I'm going to look and see if I have any R12 cans left from my old cars. If I do (or if I purchase a can or 2), shouldn't it be relatively straightforward to recharge the existing system for now?

 

Depending on how bad the leaks are, the recharge may only last a brief time. If that is acceptable, then recharge w/ R12. A little lubricant would be good to replace that lost in leakage. Get a small can of R12/lube (check ebay for $24.99!).

I would suggest a vacuum leak test before starting this recharge. Vacuum for 1 hr and then close gauges and monitor.

If system will hold vacuum for at least 1 hr (perhaps 10 in hg max loss), then recharging may be worth a try. If vacuum falls to ambient w/i 10-15 mins, you're wasting money/time IMO.

good luck

 

If I do a vacuum test, first I would need to evacuate the system correct? (I don't want to vent the system. Although at this point there may not be much R12 in there at all)

To complicate matters, at the moment I am pneumatically challenged. I have a Robinair vacuum pump which runs off my air compressor. Unfortunately my air compressor tank sprang a leak, so I am searching for a replacement/fix.

I do also have an older standalone vacuum pump. I just don't know if it is up to the task.

If the system vacuum tests ok, how many R12 cans to fully charge it?

 

Yes, very hard to vacuum w/o evacuating

Vacuum pump is better than a venturi "pump" usually. You need to get to about 28-29 inches hg to pull moisture out. Otherwise when you do the test, pressure will not hold as moisture evaporates.

good luck