AC not working -- what to check first?

After a front end wreck, I replaced my 2005 Prius AC condenser and the high pressure line (it came with the sight glass and pressure switch). I don't know if the AC was on during the accident or not. I don't know how much compressor oil was lost. I know the best way to make sure the right amount of oil is in the compressor is to remove it (is removal really necessary or is there a drain port?), pour out the oil, and refill with correct amount. But, I thought I'd try charging the system and see if the compressor at least turns on. So, today I evacuated it, made sure no leaks, then held a vacuum for half hour to remove moisture, filled r134a until low side was at 30 psi (outside temp 72F). I powered up the car and set AC to MAX COLD and the fan to high. Inside cabin fans were blowing air. MFD AC button was "lit". Radiator fans not turning. Air not cool. What should I check first? Fuse? How do I verify if the AC compressor is turning (other than feeling the high side is hot, or measuring high side pressure)? The key here is the radiator fans are not turning -- start with the fuse? Which fuse(s) would I check? If fuses OK, what next?

 

I didn't weigh the freon I put in. I was going by the low side pressure. I filled it until it read 35 psi. Was that a bad way of doing it? I could add more freon, but the pressure would go above 35 psi and I read on this forum that normal is about 22-36 psi low side (199-228 psi high side). I suppose I can check the pressure cutoff switch for continuity. It seems to have 3 or 4 pins -- which ones to check?

Where are the AC and radiator fan fuses? I looked on both fuse and relay blocks under the hood but nothing is labeled AC or FAN. I read somewhere on this forum the fuse/fuses are located under the dash. I found that fuse block, but I lost the cover and don't have the owners manual -- don't know which fuse to check. And, many fuses are missing; I need a diagram of the fuses in that block if anyone has one please.

 

I think I found a diagram on Google. Not sure if it's for 2005.
http://www.vfaq.net/proj-pics/fuses/JB-fuses.gif

 

Thanks, but what is "RDI"? Will that prevent the radiator fans from working?

 

I located the "RDI" 30A fuse. It is along a strip of fuses that seem integrated and don't resemble the kind you can pull out and replace (?).

I can't locate the other 30A fuse for the FANS. Here is a list of the fuses from the engine room Relay/fusebox cover (which I do have):

JUMPER TERMINAL
DC/DC 100A (rt side column)
P/I 60A (left side column)
HEAD MAIN 40A (left) & PS HTS 50A (rt)
RDI 30A (rt)
P CON MTR 30A (lf) & HT R40A (rt)
ABS-2 30A (lf) & EPS 50A (rt)

Below these fuses are a group of mini blade-type fuses.
The left column of fuses starts with P CON MAIN (7.5A) and ends with ABS MAIN1 (10A). The right column starts with FR FOG (15A) and ends with CDS FAN (30A)....what is "CDS FAN"? Is that the radiator fans?

I used freon from a big 30 lb bottle that I had bought many years ago. I should've put it on a scale and weighed it while I filled my system (crude way).

 

After reading the service manual, I can answer my own questions:
o Silly me. That "strip of fuses that seem integrated" are the fusible links. They look like a piece of aluminum cut into little "s" shapes.
o The radiator and AC fans are individually powered through the FAN #1, FAN #2 and FAN #3 relays in relay boxes under the hood. These relays get their power from fusible links RDI and CDS FAN and the 7.5A fuse that powers on when the ignition switch is on.
o These 2 fans are sometimes run in series, and sometimes in parallel, to meet cooling demands. The relays and many ECUs decide when.
o CDS FAN means AC Condenser Fan.
o RDI probably means Radiator Fan.
o The pressure switch near the sightglass on the AC high pressure line has 4 terminals b/c it is a dual pressure switch. I'm guessing it cuts off when the pressure is too low or too high.
o The manual also mentions a "single pressure switch" somewhere in the car. Not sure where or what it does.

I measured for continuity at my dual-pressure switch and it is open. This tells me I need to add more r134a until it closes. I'm fairly confident the dual-pressure switch is good, b/c it is new when I replaced the AC line. I have 35 psi on the system low side. Apparently, it's not enough to close the low cut-off pressure switch.

Thanks all for your suggestions. They helped me get ideas.

 

Just for clarity, what I called the "7.5A fuse that gets power when the ignition is on" is the 7.5A "ECU-IG" mini fuse in the Driver's Side J/B (fusebox) under the dash. In case someone else is reading this someday and needs to know.

 

AC works now but getting error sometimes "check the connection of the air conditioner".

I'll keep updating on my progress here, and I have new questions for the group:

Since the low cut-off switch was "open" (used a DMM to measure it) and it is a new part, I decided to add more r134a. Indeed, as VERTEX suggested, as I added more the cutoff switch closed. I reconnected the switch connector, turned on the IGN, and continued adding r134a until the low side pressure was about 30 and the high side was 180 WHILE COMPRESSOR RAN. All fans were turning, air was ice cold, all was good. The reason I kept adding up to 30/180 psi was because I continued to see bubbles in the sight glass (manual says to charge until bubbles disappear, and then add some predetermined amount more - which I have no way of measuring).

Questions:

1) I disconnected the charging hoses and drove the car a bit. Sometimes, switching the AC on yields an error message "check the connection of the air conditioner" on the MFD. Other times, no error message. When the message appears, there is no outside temp reading displayed. In fact, the whole MFD screen is green.

2) One out of 5 trips (I drive an hour to work each way), while listening to the radio, the radio will power off. I'll just push the radio power button and it will turn on again. Maybe 10 mins later, it may turn off again, or it may play for an hour no problem. Four of 5 times, it doesn't power itself off. Could this be related to #1?

3) My MFD seems very sluggish at times. I may press the AUDIO button once, and 20 seconds later it switches to Audio mode. Other times, it's lightning quick. Is something wrong with my MFD? Could this be related to #1 or #2?

4) My check engine light is on, and we believe the code points to a faulty air fuel ratio sensor. I bought the part and haven't installed it yet. Could this be causing #3?

 

AC works now. Am I supposed to see foamy liquid rushing by in the sight glass?

Forgot the main question:
5) I pulled a vacuum for 30 mins, checked that it held with the vac pump off, and then added r134a slowly until the cutoff switch kicked in and then I added more until low=30/high=175. While adding r134a, I always saw foamy liquid moving past the sight glass. I was hoping when I added enough it would go clear, but I stopped when pressures reached what they did. Do I have moisture or air in the system? How could that be?

 

"check connections to the AC" error message on MFD?

Thank you, Patrick. You are right, the MFD stopped working once and then it started working again. The loose connection causes it to act sluggishly, the radio power to turn itself off, but the "check AC connection" error too? Maybe Hobbit can chime in here. I was/am worried that air or moisture in the system will cause eventual damage (I guess internal parts can rust) or moisture can cause ice blockage. I read up that the sight glass should show clear when AC runs, and I think you only see bubbles briefly when you just turn it off. I must have air in there. I will leave it alone for now.