964polar

I assume I am low on refrigerant. Still I want to do the proper checks before I fill it.
I have checked the wiring and the clutch on the compressor this weekend and it works. How can I check the relay in the engine compartment??
When I push the A/C button while forcing the compressor with 12V, the front fan in the left fender for the A/C goes on and off/on and off for short moments.

Would you say this is and indication of low refrigerant?
How do I see if the car is converted to R134?? On the valves? What do the R134 valves look like?
Is the 3-way valve automatically released at fill-up and allows the relay to activate the compressor??

I have gone through a lot of threads but I still need help on the above.

Thanks a lot for any input.

Indycam

Do you have ac gauges ?

http://www.sadik.net/nissan/howto/ac.htm

1/4 flare (R12)

1/2" Acme (R134a)

Smokin

Henrick... Sounds like low refrigerant. When the compressor cycles on and off... It's a sure sign. You can buy a cheap set of gauges and do it yourself.

The R-134 conversion may have been done to the car. The high and low side are larger than regular R12. Most guage sets will have a regular R12 connections with adapters to use on R-134.

Not sure about the relay... I never checked mine. My Dad bought a case of R12 before he died over 10 years ago. It was in my Mom's garage. I took the case a few months back and charged my system. It blows ICE cold now! You can still find R12 if needed... Though you will pay a premium. Most shops can convert for you for a couple o hundred bucks. (That includes a fresh charge too.)

If you do this yourself... You should change out the receiver/dryer located behind the drivers side front fenderwell. It's an easy swap.

wsybert

The 134 ports are threaded on the inside, the R12 ports on the outside.

964polar

Thanks, I will check my valves tonight.
Then I have to check my ceramic resistor as well I guess since I meant that my A/C fan is going on/off not the compressor.

paulnott

Hi Henrik,
I've "messed around" with the A/C on my 964 and several other cars. Here's what I learned;


- if you temporarily bypass the 3-way pressure switch and the clutch then engages you can almost be sure it's low on refrigerant (or too high - unlikely). Don't run it like this for any length of time however as it's likely to damage the compressor.
When you refill, this valve is automatically released via pressure.

- The R134a valves are push fit connections and the R12 a screw fit (at least in the UK, but I don't believe it's any different in the US or Europe) so it's not possible to accidentally refill with the wrong refrigerant. As mentioned above, the R134a valves have a thread on the inside which is used to locate the dust cover.

- If your front left fan is "cycling" it's likely the resistor as you say. I had the same problem. The resistor can be found mounted on the condensor with an "allen" style bolt. It's a devil to get off, but not impossible - use plenty of WD40 before starting.

- If the car has not been converted to R134a, you can use an R12 sustitute (in Europe it's unlikely to get R12 itself). Freeze12 is one which can be used - actually I use it myself and it works fine. Alternately, moving to R134a is not a big deal on these cars - as mentioned you only need a new dryer/receiver (I sourced one via the US as it was way cheaper) and you will need a professional to recover the existing refrigerent, vacuum, test and refill. I plan to convert mine at some point, just didn't get around to locating the "professional" to do the job yet ;o)

I hope this helps. If you're planning to refill any refrigerant yourself, be careful - A/C systems are high pressure and the contents dangerous. Please read any instructions with any supplied equipment carefully and use some form of eye-protector.

I hope this helps. Good luck.

Cheers,
Paul

964polar

Thanks a lot Paul.
Is there a distributor of Freeze 12 in Europe?, I have not been able to find one yet on the web. I guess there is no issue about shipping gas bottles via DHL right??

Cheers

paulnott

Hi Henrik,
here's a link to the site that delivered my Freeze12. They're in the UK, but I suspect they may ship to Europe (I haven't checked).
http://www.car-air-conditioning-supplies.com/

Cheers,
Paul

964polar

Thanks again Paul!
A good site on this (right) side of the pond.

Cheers

paulnott

Hi Henrik,
no problem, glad to be of help.

You may want to give them a call rather than just order on the internet. They were quite helpful with advice and I ended up buying a can of "stop leak" (which includes a dye so you can spot leaks) and an oil charge also.
You can also ask for advice on mixing R12 with Freeze12 - this works although I believe (certainly in the US) is not legal.

Cheers,
Paul