Yota.Jay

Today I decided to maybe look at my a/c system. I pressed the valve in on the high side on my 87 yota pickup. Nothing came out. So i decided to add some 134a (yes i know they need r14 or r12 but it doesnt hurt to try). After filling two cans which it did take; the compressor didn't kick in. Even though I pressed the a/c button on the inside. I bypassed the switch and went straight for the compressor to the battery. Well it comes on and the air is nice and cold. So I know for a fact the compressor it not at fault. Maybe a switch or something? How do I go about testing this? I even hooked my a/c gauges up to it and the low side had 55-60 and the high range was 245-250. Which was fine.

I have read some threads with the same problem but different symptoms. Tomorrow I will check fuses and relays.


Thanks for the help,

Jay

scope103

Oh, jeez. You have the gauges but you still decided to cowboy it? I know you planned to only let "a little bit" out, but if enough people did that we'd all be shopping for SPF 500 sunblock in a few years.

Doesn't hurt? Where did you get that idea? I'm no A/C expert, and I get the sense this is somewhat controversial, but I understand that adding R134a without replacing the oil and seals will give you a goopy, gloppy mess which will destroy the compressor in just a few weeks. AFTER you've figured out the problem is in your A/C amplifier http://personal.utulsa.edu/~nathan-b.../2aircondi.pdf If I'm wrong then there is a whole industry (A/C conversion) that was built on an elaborate lie.

Keeping in mind what I said about "I'm no expert," here's everything I know about A/C: https://www.yotatech.com/forums/f116...-r134a-284801/

Yota.Jay

Why spend $400 if it will get by. Test and see.

superex87

Just adding R-134a to the system will cause a lot of problems.

1st- If the system was empty then you have a leak. Need to find and fix this first.
2nd- R-134a is not compatible with the R12 oil. You need to dissemble and clean out the entire system. They make flush kits for this.
3rd- Seeing as you "just added" refrigerant and did not vacuum down the system, any moisture in there is currently mixing with the compressor oil and making acid.....this will quickly destroy the entire system.
4th- see 1.

rustypigeon

Those readings are not fine. They are both too high which indicate air in the system. This is to be expected when adding refrigerant to a system that has zero pressure. It should have been drawn into a vacuum after fixing the leak and replacing the receiver dryer.

In your case a proper R134a conversion should have been done (after fixing leak) rather than adding a couple R134a cans to an empty R12 system.

Yota.Jay

As far as I was told my readings were fine. My original question was to help and see if there was a way to get my air button fixed?

I will say that it has been retrofit for r134. Not sure if that helps or not.

jaysson_2012

Since you really don't care about the built in precautions to protect the system. Just run 12v from fuse box to your switch, then to the ac compressor. Then your switch will work with no pesky low pressure shutoff

Yota.Jay

I'm not sure what exactly to do and I was suggested just to retrofit it. I may just do that

scope103

You know you have a leak in the system. That's where all the R12 went. You know you have air (and some water) in the system. That's what replaced the R12.

You can work your way through the section describing how the clutch is energized, http://personal.utulsa.edu/~nathan-b.../4generald.pdf, and with a multimeter you may be able to track down a defective component (if it's not the amplifier). But I fear you may just be chasing your tail trying to fix one thing when you (should) know in advance that your system can't work properly.

Outsane

I was having issues with gettin my compressor to turn turn on...

I fallowed the Manual and found out it was the over temp swtich.

good luck

mwisham

Although I am an ASE certified A/C tech, I will not fault you for trying to vent a small amount of refrigerant to see if there was any in the system.That tiny amount won't kill anybody and global warming is the biggest scientific hoax since the Piltdown Man anyway.
I will fault you for adding refrigerant w/o doing a good vaccum on the system and checking for leaks. Those guage readings are not ok. 200 to 250 on the high side is ok depending on ambient temps, but the low side should be closer to 35. Also, like somone else said, R-134 is not compatible with R-12 oil. You need to flush the system and refill with PAG oil. Then you can find the electrical issue that is keeping the clutch from engaging.

Yota.Jay

Another ASE guy...love those ASE style questions. I checked before actually pushing the valve and then when I did nothing but a tiny gasp came out. The low side was on 35 until the
A/C Compressor kicked in. The high side was even in on 250 until the compressor was turned on. Once I went from the compressor to the battery (by passing the switch) that's when I received my readings. My teacher Mrs. Spence (ASE Certified Master Technician) use to say the same thing.

mwisham

Those readings, 35 low 250 high, should be with the compressor running. Don't know how long your system was not operational, but there may not be enough old oil in there to worry about. That being said, it will never cool as well as it should until you pull a good hard vaccum on it to remove any air and moisture from the system.
BTW I'm in Albany not too far away. Dang sure gets hot in south Georgia doesn't it.

Yota.Jay

I'm not sure either. Well guys I'll get the 134 taken out and add some PAG oil. But first I'd like to figure out my electrical issue.

Thanks all for your advice and help


Jay

Yota.Jay

Fixed the problem A/C is now good and cold. Onto the next issue. Hopefully it will be as easy to solve.

Jay

mwisham

now you have to tell us how you fixed it. What was causing the lack of power to the A/C clutch?

Yota.Jay

Well first I checked for continuity in the circuit...nothing...well I checked the fuses. They were good. Didn't know there was a fuse(s) inside the cab. So I checked them also. They were all still. Good. So i begin to check the wires in between and pulled a long wire out. I got a new wire solder some connectors..used heat shrink tubing and connected. Got it back working. Now A/C kicked in. There was no oil at all in the compressor so...

mwisham

Thanks for posting the resolution to your issue. Too many people post a problem on here and never follow through when they find an answer. If you had that problem, there are probably more people with the same issue so now they can follow your thread and find an answer to their problem.

Yota.Jay

Yeah check all fuses. First make sure your fuses are great. Looking at a wiring diagram; one would know that power comes through the battery through a fusible link. From there it goes to the heater motor. One the same line as the heater mother (power) is a fuse (10A). Make sure that it checks out. Then check the switches and other stuff. Volt Meter will help. Remember Cars/Trucks love DC and cant use AC.