RumbleFish

Any idea what from?

bamaredneck

This may not help as it sounds your compressor is bad. My AC was not working very well and i looked into the 134 conversion, $$$. There is something called freeze 12 that is r-12 compatible it is $12 a can versus 6 for the 134 and $40 for r-12 . My ac works good for now. If it lays down later I will look at the 134 conversion.

92DIESEL

Well I finally got some guages, but I don't know what the readings mean, so that's where you very knowegable gentlemen come in, I hope

Engine off: Low 48psi, High 70psi
Engine runninge: Low 102psi, High 0psi

The compressor kicks on and stays on, but no cold air.

Please help, and if I have to charge the system I am leaning toward the "alernative" refrigerant (because its cheap)

Thank you all in advance,
Michael

leper

With the ac off, the readings should be equal. With it on, and low on freon, your readings are backwards. Is it possible you mistook the low and high side?

92DIESEL

OK first thing, I don't know ANYTHING about A/C except it makes air colder.

The fitting near the firewall is what I hooked the HIGH side to, and the one by the little bottle with the site glass I hooked up the low side.

Did I hook them up backwards

I did get a little oil? out of the fitting by the bottle in the front when I hooked up the gauge. Is that normal?

Thanks again guys.
Michael

KB440

You had them hooked up backward the low side is near the firewall.

92DIESEL

Oops, so I guess it would be

Engine off: LOW 70psi High 48psi
Engine on: Low 0 psi High 102 psi

Any ideas what's wrong? Or anyone near me that knows how this A/C thing works.

Thanx again,
Michael

leper

You are low on freon. The fact that your system is not empty, is a good thing. Suck out what is in there, and pull a vacuum. disconnect the hoses and retrofit it to 134a. Hose fittings and oil. Charge the system with about 90% of what it says for R12. Enjoy your AC.

NorthWestMatt

Is it possible that he has a low-side pressure switch bad since its not shutting off the compressor then low side drops to zero?

Jim Lane

Michael,
I would consider using a drop in like HotShot R-414B,
http://www.icorinternational.com/ind...&products_id=4

AutoFrost R-406A,
http://www.refrigerantsales.com/webdocs/af/af_qa.pdf


Freeze-12
http://freeze-12.com/,

Or other similar replacements so you don't have to flush the system and replace the receiver/dryer, new oil, need to install an auxiliary fan.

But if you are going with the R-134A, I saw an add in the paper this week at Pep Boys they have R-134A for $2.99 per can after rebate limit 4.

I do not need any but for that price I might get a dozen or so cans.
The add should be nation wide.

Of all of their retrofits I have done, the Hot Shot works the best.

Also whoever uses these new drop-ins remember that when there is a small leak in your system and you just "Top it off" it is not going to work as well as when it did the first time it was charged, blended gasses will fractionate meaning the blends will break apart at different pressures, and components of the blend will leak out first and change the original makeup, it might work the first time but then it will not cool as well after you top it off. You will need to evacuate the system and recharge it.

Also be careful connecting your gauge manifold up backwards, the Low side is a compound gauge and its upper limits are not high enough to handle what an AC system will have when operating, they can go over 300 PSI easily.

The gauges use logic, Blue is Low side (cold) Red is High side (hot)
Also to minimize the refrigerant loss when you disconnect them, disconnect the Blue hose with the AC running and disconnect the Red hose after you turn it off and wait about 1 minuet for it to equalize.
You can also buy quick disconnect ends for your hose set at most HVAC supply houses.
Jim

Jim Lane

The low pressure switch is on the High side of the H-valve and will limit the compressor if the total charge is too low, the suction side pressure varies a bit and in some instances can get near a suction but usually is around 30 PSI depending on the ambient temperature.



Jim

92DIESEL

Jim, thanks for chiming in. As well as everyone else.

So I am low on refrigerant I don't really want to go the R-134 route.

Can I do the propane thing or should I stay away from that also.

You guys are the best, to be able to diagnos a problem from 3000 miles away, this site rocks

Thanks again,
Michael

farmer0_1

got to get mine looked at too. one time works great good and cold then next time no worky. some times in the same day. seems like i hear the pump running on and off when not working have to really have a good look see.

BRUISER

I have used Propane in a bunch of my old vehicle with no issue.. but be warned propane does combust so if you blow your vehicle up it is your fault

92DIESEL

Well I've set EVERY vehicle I've owned on fire except the truck and my wifes car, so I'm not worried about it. (and no, none of them were on purpose)

So can I just add the gas or do I have to evac the system first, and how much do you put in?

Thanks again,
Michael