2007 ac swap, will update untill finished/solved

[komichal]

Hats off to you sir, this is some serious work!
By the way - does the cool air start to blow instantly after you turn on the AC, even in very hot conditions?
My AC sometimes takes literally 5 minutes to start blowing cold air, espacially when the outside is awfully hot and the car sat overnight on the parking lot.
I asked the dealership to check - they added little bit of refrigerant and measured the pressures - all was OK and they were not able to find a problem. They changed the pressure switch "for preventive purposes" but no help. Could it be that the whole AC system is just worn out after 15 years of service?

[sh0rtlife]

Originally Posted by komichal

Hats off to you sir, this is some serious work!
By the way - does the cool air start to blow instantly after you turn on the AC, even in very hot conditions?
My AC sometimes takes literally 5 minutes to start blowing cold air, espacially when the outside is awfully hot and the car sat overnight on the parking lot.
I asked the dealership to check - they added little bit of refrigerant and measured the pressures - all was OK and they were not able to find a problem. They changed the pressure switch "for preventive purposes" but no help. Could it be that the whole AC system is just worn out after 15 years of service?

ive yet to have it hot enough outside to put it "thru the ringer" to so speak

however at 79-82 with some humidity it blows ice cold in say 30 seconds or so

i do have some further notes im about to post tho that may help

[sh0rtlife]

HUGE FOOT NOTE!

for anyone charging the system themselves, or even having issues with the system, ive run into a handfull of bogus write ups procedures etc that dont actually apply to the yaris or such a small system..not really sure but even TOYOTA's own checklist and procedure was GARBAGE

so after some falls positives, some head scratching and lots of trial and error i found a combination of new and old school that works

obviously you need to vac and leak test the system, being paranoid i did -25 vac after 20 mins disconnected my gauges and left the car for 24hours, came back the next day and was still holding 25, so i know the system is sound

baring any bad parts..heres the "fill" procedure i found to finally give me predictable ice cold air on demand
even a "cheep" set of high/low gauges will work but dont try and do it with a single on the can gauge as youll NEVER get it right, and youll be chasing your tail for days

start the car
add "some" refrigerant like a can of "first can", keep adding it till the system starts to cycle
now watch the gauges, youll find that the system "kicks off" at around 29 on the "low" side and 110ish on the high side, but will also kick off if things get wildly too high as in pegged gauges LOL

pull up a temp to psi ac chart, youll need it and a temp reading of outside air
at this point youll need to charge the system SLOWLY and you may find yourself venting some as needed..i recommend a "spent" empty can

with the AC on MAX and the fan on MAX, you either need a second person, a block of wood or a lil bit of dancing

1500RPM is your KEY point that your working around..anything lower and youll chase your tail, anything higher and the same thing, so if you can set your car to hold that..DO IT, if you cant..aim the gauges thru the windshield rev and watch

today was 70ish so i was shooting for 35-40 low side and 145-160 high side
getting the low side up seems straight forward but until you hold the 1500RPM youll either get way off readings or wild fluctuations and even redlined over pressures, i found myself adding to the low side, and doing alot of swapping to an empty can to vent the high side till i got it close

DO NOT use the fan as an indication of the AC on..watch the gauges, you should watch them and see that when the low drops to 29 it kicks off and the high side will now fall, at some point you'll see the high side start to climb again this tells you that the compressor is cycling, if fact watching the guages and listening closely youll be able to verify if your transducer is working correctly as well as it has both high and low psi cut outs..and those cut outs are 29 low and something VERY high..not sure exactly how high, low sides all that really matters

the sweet spot is to add to the low side while the compressor is running and when the low side is at its lowest psi but before the compressor kicks off, theres a sweet spot....yes you can add it whenever but it may toss things out of balance quickly if done while closer to the high end , what your trying to do is is add to the low while keeping the high from dropping too fast, if your adding to the low side above 35 while the high side is sliding down what youll likely end up with is next cycle the high side spikes out and you find yourself venting some off...i found myself only adding from 32-29

the issues i had with alot of the procedures was setting the ac to mid not max ment when i hit max id get HUGE spikes in the high side 400psi!, and the same went for any rpm, what i had was a "charged" system that looked right on paper at idle, worked briefly and unreliably or not at all at standard engine speeds

at 1500rpm you want to see the high side fluctuate minimal 5-10psi tops, if it goes high and keeps climbing, you need to vent/remove, if it goes low or drops fast you need to add to the low side...simply put, if its swinging fast do ALOT if it swinging slow do small amounts as your getting close...but make sure the sytem is either cycling a couple times between or staying on rock steady..honestly once you can get it to stay on rock steady your close enough to just leave it alone

what i found myself doing was venting to a catch can then re-using the catch can on the low side and kept dancing till i got it and it held, mind you at idle its NOT right and the compressors going to do a good bit of cycling on/off however toyotas AC system for the yaris was NOT ment to be run at idle as a setting for "at idle" will mean anything above 1500rpm and the high side will spike into shut down and you wont have ac again till you turn off the system for 5 mins(the amount of time it takes for the pressures to equalize) at which point if you turn it back on it will work briefly


hopefully between this and the previous write up it should basicly solve alot of ac woes

[sh0rtlife]

BONUS NOTE

to EVERYONE who has a yaris with or without AC, are you aware there is NOT a water flow control valve?, as in even on MAX ac you still pump hot water thru the heater core into the cabin of the car, which diminishes the cooling , heck on a hot day without ac and your heater dialed to cool and off its STILL PUMPING HOT WATER!!!!!

im currently in search of the best fitting "fix", obviously a standard issue water bypass valve is in order..i mean most american cars and euro cars have had em since the 40's , tho they useualy only locked off one side of the flow, modern units shot off both sides and do a return flow as to keep the coolant cycling in the hoses, just not thru the heater core

yes you have a "blend" door but that doesnt mean that the blend door isnt radiating 210degs of heat, always wondered why as a passenger my left toes would be burning on a long drive...now i know why

currently eyeballing the unit off a 2001 ford explorer sport as its a simple inexpensive design....but trying to find something that matches our hoses as well as will sit cleanly in the engine bay (hoping to match hose distance apart on the core side) is going to be the true trick

either way ill have to put a switch on the blend door movement so that once set to "no temp" it shuts the valve, now weather thats an electric switch or a vac switch is yet to be determined

[IronYaris]

Mad respect. Every other mechanic shop i've asked around my area suggested buying a car with AC.

[sh0rtlife]

Originally Posted by IronYaris

Mad respect. Every other mechanic shop i've asked around my area suggested buying a car with AC.

everyone here seems to be under the same statement "go buy a yaris with it"

thats why i took the stand and did all the figuring and grabbed everything and just did it

all in used parts, save for some key wear parts, charged and blowing cold less than 250$, alot of thats going to be simply finding the used parts and being patient with prices, i managed to get most of my parts from pick n pulls, and i also bought an entire heater box assy in that total mostly to prove that a non AC box was the same as an AC box..i wanted ZERO supprises and zero setbacks when i pulled the dash apart

id wager if i had to do it again i could do it with a mix of new n used for about 150-200

[sh0rtlife]

im off to testing my setup before "hard wiring"

im using "Four Seasons 74809 Heater Valve " in conjunction with a 05 corolla ven solinoid(or i think thats what it is), will grab the part number when i post the pics

for now ive got a rocker switch floating in the glove box

the heater valve is a dead match for the hose sizes on the yaris and the spread is VERY close, nothing a couple of 3-4inch hose chunks cant overcome

i did need to tap into the engine vacuum which was tricky, so i used a fuel pressure fitting and replaced the gauge outlet with a small barb....NOTHING on the yaris required cutting and my cost is 20$

will see how the testing goes but i suspect no more long travel cooked feet on the passenger side and no more heat in the car when you dont want it

assuming everything works as it should and i see no reason it wont....the next step will be to make the solinoid trigger when the heat is turned off...not the fan but the temp dial, looking at the spare heater box ive noted a couple of empty screw holes not far from the tempeture diverter flap as well as a L shaped part on the flap assembly hanging out that has a hole in it akin to what youd find in a door handle/lock, so my current running theory is to setup something like a brake switch on a spring attached to that

anyway, will be a long couple of days of driving so will report back with details after the testing....this could very well be ideal for anyone wanting less heat in the car in the summer but doesnt want AC

[sh0rtlife]

initial testing has been done, humidity has been pretty gnarly

ive run into a couple of issues where "idling a long period causes the system to shut down if running high fan...i suspect the 4seasons valve at the condensor is faulty and causing too high of pressures....its a known issue, so ill just order up a genuine denso

[sh0rtlife]

so...heres a semi fresh write up for "heater bypass"..and this applys to you non AC guys too who want "unheated" fresh air..which isnt something the car can actually do without this mod...i havnt entirely solved the "automated" end of this "yet" but have a good idea of how to do it

order up
Four Seasons 74809 Heater Valve
find used or buy
25860-62010 Toyota Vacuum Switching Valve Solenoid VSV
youll also need 1 foot of vac line and 8 inches of heater hose and 4 hose clamps
and a "y" for a vacum source..imo the simple fix is to use a fuel pressure block and a barb fitting off the brake booster line

pretty simple setup really
use a strip of steel and mount the vac valve to the heater valve body(they sell premade units for "LS swap" aplications for 200$), run the lines as seen in the pics
vac source to the bottom nipple
vac canister to top...run it any other way and it wont work, this allows for when the unit is "powered" that it sucks the valve shut and simply lets the vac of the engine hold it there, when its "un powered" it allows only the canister side to "vent" and release
as far as wireing goes, it doesnt matter both work as pos/neg pick one to ground and another to power..your choice simple 2 wire

how you go about switching it on/off is up to you....for testing i have a switch flopping about in the glove box

with some looking at the heater box however ive found theres a cog on the heat control flap that moves to a fixed point once you get to "neutral" of the heat selection, theres also a neerby threaded hole on the heater box....my running idea is to either use a motorcycle foot brake switch(small slim spring loaded) or a modified brake switch from another yaris..the obvious choice of a bike brake switch is they are super small and easily mounted and have a wire/spring pull to activate, and the cog on the box pulls up and away from the mounting hole

anyway ill update that bit of info when i settle on how i do it

for now the ability to "turn off" the heat entirely has my feet happy, but being able to pump cool flowing air from outside without it going thru a hot heater core is VERY nice, so much so that AC is needed considerably less

[tmontague]

Great write up and kudos for paving the way on this. I'll admit, it seems to have cost a lot less than I would have thought.

Quick Q for you and my apologies if you already answered it: why did you not just fill the a/c based on weight and essentially be done with it?

I understand dialing in pressures to potentially improve performance over factory specs, but as a starting point why not just use the factory fill weights as a baseline?

IME Japanese manufactured vehicles were never designed to have proper ac cooling at idle, they are sized for efficiency and to perform once driving.

All Japanese vehicles I've owned (Toyota, Mazda, Subaru) have decent ac at idle (~60F vent temps) but improve quite a bit once moving (~45F vent temps). This makes sense as having an ac system that works great at idle means you are just burning gas in the other 90% of times you are using it and actually driving.

[sh0rtlife]

Originally Posted by tmontague

Great write up and kudos for paving the way on this. I'll admit, it seems to have cost a lot less than I would have thought.

Quick Q for you and my apologies if you already answered it: why did you not just fill the a/c based on weight and essentially be done with it?

I understand dialing in pressures to potentially improve performance over factory specs, but as a starting point why not just use the factory fill weights as a baseline?

IME Japanese manufactured vehicles were never designed to have proper ac cooling at idle, they are sized for efficiency and to perform once driving.

All Japanese vehicles I've owned (Toyota, Mazda, Subaru) have decent ac at idle (~60F vent temps) but improve quite a bit once moving (~45F vent temps). This makes sense as having an ac system that works great at idle means you are just burning gas in the other 90% of times you are using it and actually driving.

i did initially fill to spec, but im not sold that said spec is for a "fresh install", as it wouldnt get up to pressure to kick the pressure switch, of course i also think the new valve is at the condenser is semi faulty or sticking which could have caused the false start and lack of pressure, its rated as an oe replacement but with as sensitive and slow as it is im probably going to empty the system and re-fill again with a direct denso part in its place

[CrimsonEclipse]

I apologize if my reading comprehension is not on point:
So you installed an A/C system into a car that did not have one?

You're a madman, and you have my sincere respect.

[sh0rtlife]

Originally Posted by CrimsonEclipse

I apologize if my reading comprehension is not on point:
So you installed an A/C system into a car that did not have one?

You're a madman, and you have my sincere respect.

sure did.....and boy oh boy is it nice to have, tho i have to admit you can FEEL the power loss at low rpms, anything above 3k its not noticed unless your going up hill


adding options where they wernt is always fun and useualy not so "plug n play"....while i was in there i noted it looks like the harness is there for power windows....when i find them...but thats quite the rabbit hole with needing all 4 door panels, motors, switch panels switches and harneses

[sh0rtlife]

the final piece of the puzzle is you will need to make sure the car has the fan#2 relay, but you will also need to make sure the car has the "fan resistor" which is mounted on the left frame rail beside/below the air box, without that your condensor will run HOT, and also this resistor is how the AC forces the fan on, without it the ac cannot force the fan on!!!!!


as far as i know this whole thing has now been 100% solved, still working on a automatic water flow cutoff but the AC side of things is set in stone solved!

[toyotavios_11]

my respect to you bro