2006 prius-a/c compressor won't come on to charge?

Discussion in 'Toyota Prius Family' started by phoebeisis, May 31, 2016.

  1. phoebeisis

    phoebeisis Well-Known Member

    2006 Prius 104,000 miles-
    9 months ago the AC started blowing "not cold" air
    I put a can of suitable 134a WITH the correct oil in-and it blew cold for about 6 weeks
    then the weather became a bit cooler-and my son drives it-
    so I ignored it as it cooled less well
    Yesterday I tried to recharge it again-no go-the AC literally seemed to be blowing HOT air
    the compressor wouldn't come on
    Guessing so much 134a is gone that it won't come on-just like a regular AC
    How can I trick the compressor to come on so it can accept the charge
    Yes I'm aware the orange covered cables are 200+ volts-and could kill me-
    No I don't want to die-so I'll follow any instructions that involve electrical connections-carefully
    Frankly I might just chicken out
    Oh-I can't -couldn't find any compressor fuse??
    I found a A/C fuse under the dash-but it was just 10-15 amps-12 V amps probably-so no way is it the compressor-110 watts-?? Must take 1000 or more watts to drive that compressor
    ps I posted in another forum-easy to guess which.
    I got a perhaps correct-but unhelpful response
    " it is leaking bring it to an AC shop or you will damage the compressor"
    1)Duh-no kidding-i† is leaking-never would have guessed that
    2)Duh- I might break it more -no kidding
    3)But most importantly-if I wanted to spend $1300+ to "maybe get it repaired"-I would have done that.
    No ac repair is less than $1000-most are more-I don't drive it-if it is dead-I'm not spending $1000 or more for a repair-that might or might not be a repair-finding one leak-doesn't mean that is the pnly leak-and 10 years in NOLA- AC 9 months a year-well it is on its last legs anyway

    so if it can't be recharged-it might as as well be broken-since no way am I paying $1300 for a "maybe fixed"
    in NOLA- many most shops-aren't honest-and aren't competent-for the most part this includes dealers-if I can't fix it-or a buddy and I can't-it stays broken

    Anyway any hints out there?? is there a bypass that can force the compressor to go on so I can charge it?
    If it is DOA-so be it
    PPS- Yes I don't want to get electrocuted so any cautions on avoiding THAT- will be taken seriously-
    "normal cars" can shock the heck out of you(don't ask me how I know) but the Prius can actually kill you-200-300 volts-yikes!!-driving a what 40 hp motor-what is that 30,000 watts?? if memory is working a defibrillator puts out about 300 watts for 1 second-300 joules-so 100x that??
    Geez I fear electricity!
  2. Prozac

    Prozac Well-Known Member

    I would suggest looking for a relay that might be blown. I had to do this recently to my father's Ranger. I looked like it might have been the compressor except the way that is just quit all of the sudden. Once I put in the new relay everything was blowing ice cold.
  3. phoebeisis

    phoebeisis Well-Known Member

    Thanks for the tip
    Yesterday I "hunted" for a A/C compressor fuse-no luck-
    The fuses in the usual fuse blocks-must be for "just" the 12 v accessories-I guess
    and the electric compressor-wouldn't be 12 volt-so maybe I am looking in the wrong place for a fuse??
    Anyone know anything about the fuses or relays on the electric compressor??
    Thanks for the relay tip
  4. 08EscapeHybrid

    08EscapeHybrid Moderator

    I've had that problem before. Look for something like #2 here in this picture. It is the pressure switch. If there is a low freon charge, it disables the compressor. I've basically unplugged the harness, and shorted it with a straightened out paper clip to fool it into running. On rare occasions, this switch has been bad. It is a cheap part, and easy to replace. It just unscrews. There is a schrader valve under the pressure switch, so if you take it off quickly you will lose very little to no freon.

    Now, you know you have a leak. You don't want to spend a lot to fix it. I understand. This is the route I would take.

    You will need:




    Take the cost of the tools as an investment. Harbor freight always has a 20% off coupon available.

    Hook up the vacuum pump up, and let it run for at least 3 or 4 hours. You want to pull a vacuum and hold it for a few hours to allow any moisture in the system to boil off and be evacuated. Immediately chase it with the can of stop leak. Since the system is negative pressure, it should just suck it in . Then chase it with the proper freon charge, minus one can (There's freon in the stop leak). Let the system run on a/c max for about 20 or 30 mins to make sure the sealant is well circulated.

    If there's nothing else wrong with your a/c system, this should get you ice cold, and keep it that way. I get a little more in depth with my own vehicles (I take every fitting apart, put new seals in, and then put special leak sealant on the threads before I put it back together)
    phoebeisis and BillLin like this.
  5. phoebeisis

    phoebeisis Well-Known Member


    Thanks-just what I needed
    Now I think I found the switch- the upper part-the black plastic "plug" with 4 wires has four female receptors-the lower-fixed part-has 4 prongs
    It is right next to the sight glass-and right next to the high pressure access valve and cap
    Now I just randomly selected two to jump-and sure enough something "new" came on
    Sounded like a fan??-a fan far forward that I couldn't see but near where a normal radiator would be-I could see the radiator fan-it wasn't on- perhaps a fan to cool the "radiator/condensor coil" the cools the warmed 134a gas?-what is that called-condensor coil maybe??

    But no compressor came on-the pressure in my install hose(has a gauge built in) was still in the red and the can didn't cool
    So I put another paper clip in-jumped it too-still no can cooling

    Which of these female receptors should be jumped-I am jumping straight across
    and how long should I wait for the compressor to kick on??

    And your picture-that little cylindrical tank in it-what is that?? some sort of liquid storage "thing"
    My switch ISN'T near that-in fact I didn't see that in mine-so maybe I am jumping the wrong plug??
    But that fan noise ISN'T present when I just turn the AC on in the car- only the fan blowing HOT air comes on-what is that-the fan that blows across the evaporator coil-"cooling coil"

    So just how do I jump those 4 female receptors-which wire color to which wire color
    and how long should I wait for the compressor to kick on-
    and am I jumping the right switch?? this one certainly gets a fan to come on-that wasn't on before?-a fan far forward -sounds like it is just behind the grill
    PS I am largely ignorant of the ins and outs of A/Cs-know how they work-
    in a general sense-it takes energy-heat-to evaporate liquids-
    that heat/energy is carried away as it expands(in the car cabin-so it sucks the heat to evaporate expand from the cabin))-then you have to get rid of the heat-and re-condense the refrigerant-that is about it-repeat repeat
    Last edited: Jun 2, 2016
    BillLin likes this.
  6. 08EscapeHybrid

    08EscapeHybrid Moderator

    If you have 4 wires, that is a dual switch. It protects the system from underpressure and overpressure. You would not jump everything at once. I would look at the harness attached to the plug. If there is a black wire in the harness, I would assume that was the ground, and I would try jumping that terminal to the others, one at a time.

    The big thing is a receiver/drier. It is designed to absorb and trap any moisture that seeps into your a/c system. The pressure switch does not need to be close to the drier. It just usually is. The pressure switch you're looking for is usually on the low pressure side though (The fatter freon lines)
    BillLin likes this.
  7. phoebeisis

    phoebeisis Well-Known Member

    Thanks again-
    the switch I was "jumped" which turned on a fan- is on the high pressure side-in series with the sight glass and the high pressure access valve-
    now it definitely "jumped something" a fan came on-fan to cool condenser coil I guess?
    I will take a good look tomorrow-
    any likelihood that the pressure switch I want-to jump the compressor on- could be on the high pressure side??-
    I copied the info you posted with links- will put it in an email to myself-and paper copy it-
  8. phoebeisis

    phoebeisis Well-Known Member

    Well I jump the switch and the condensor fan comes on
    but compressor DOESN'T?
    I'm wondering if perhaps the relay-like John/prozac suggests-is bad??
    Shouldn't there be some sort of FUSE for the compressor??
    I hate to deal with whatever power that compressor uses??
    Must be about 1000 watts or so
    How much voltage does the compressor use??
    The full 200-300v that the drive motors use?? sure hope not
    so I'm stuck looking for a relay a fuse and wondering just how much power that compressor uses-guessing it is about 12000 btus-1000 watts or so-plenty enough to croak me-I'l look for ORANGE shielded lines to compressor
    PS Yes I'm going to get the tools 08 suggests-and I'm going to sign onto that $15 FOR 2 DAYS toyota info site-get wiring diagrams and other info
    08EscapeHybrid likes this.
  9. 08EscapeHybrid

    08EscapeHybrid Moderator

    Sorry I didn't see this sooner... I guess the switch may be on the high pressure side, but I think most often it is on the low side.
  10. phoebeisis

    phoebeisis Well-Known Member

    No problem
    On the BRIGHT SIDE
    Both the Harbor Freight tools-
    vacuum pump- just $89 instead of $99
    manifold gauges $49 instead of $59
    are on sale at my local harbor freight-which is just 2 miles away
    Looked at the suburban switch-just 2 wires-

    Once I get on that Toyota site-I will hunt for "something" that will turn off the compressor-a relay or fuse
    Hoping it is "turned off" by something other than that switch-since I've jumped it-got condensor fan to come on
    but compressor won't-
    My guess is the switch would "turn off" both of those-but something else is also "turning off" the compressor
    08EscapeHybrid likes this.
  11. 08EscapeHybrid

    08EscapeHybrid Moderator

    Yeah, I bought the gauges and vacuum pump years ago. I had my K1500 into the shop several times for a/c work. They replaced the compressor and the lines, but it kept on leaking, so I had to take it in every couple weeks. Even though the guy wasn't charging me, I decided to buy the tools, and fix it myself. Haven't had a problem since.
  12. phoebeisis

    phoebeisis Well-Known Member

    I'm going to bite the bullet-
    buy the tools-safe bet I will have to do A/C work on the 1998 suburban "someday"
    it was re-done-in 2005 or so-2 years before I bought it
    must have done a good job- 11 years and 75,000 miles ago

    The prius A/C definitely gives me pause-it takes the full 200 freakin' volts-guessing 5-6 200v amps-plenty enough to croak me
    I wonder if a scan gauge mine finally "broke" (bought in 2005 so got my $$ worth)
    but I wonder if AC codes are stored in the ECU and can be retrieved by a code reader like a scan gauge??
  13. 08EscapeHybrid

    08EscapeHybrid Moderator

    11 years is pretty good. I got one better than that though. I redid the a/c in my 1981 Buick around 1994 or 1995. Still running on the same charge of R-12.
  14. phoebeisis

    phoebeisis Well-Known Member

    22 years?? WOW DOUBLE WOW!
    Well GM even then-was known for making durable AC's
    Frankly the japanese vehicles I owned for 10 or more years -1985 corolla(about 5 years good ac) 1986 pickup(10 years goodac) 1995 accord(5 years good ac) 2006 prius( 9 years until ac quit working right)
    have only averaged about 6-7 year before AC's quit cooling right
    The Suburban-11 years- 9 mine-but my 9 years just 35,000 miles of the 75,000 on this AC

    Oh I got the $49.99 gauges today-not bad- the pump is actually $99-but I can probably get a 20% coupon-
    I'm really thinking I'll have to wait until the weather is less oppressive-HOT HUMID -
    Luckily my son drives the prius-I drive the suburban-but very little in the summer
    I sub teach-so no work and very little driving in the summer-I drive MAYBE 300 miles ALL summer-perhaps 2400 miles during the school year
    08EscapeHybrid likes this.
  15. 08EscapeHybrid

    08EscapeHybrid Moderator

    Yeah, when I bought my gauges, I picked them up on sale for $25. I don't think they've been on sale that cheap for a while.

    As far as the a/c lasting that long in my Regal... I took apart all the freon lines, put new o rings in, and then put sealant on all the fittings before putting it all back together. GM just relies on the O rings. I always add sealant to the mix.

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