How to Add Freon to a Car and Manually Engage AC Compressor Clutch

How to Add Freon to a Car and Manually Engage AC Compressor Clutch

hey whats up youtube, today I am going to
be showing you guys how to add freon to your AC system and also get your AC Clutch to engage
just incase its not engaging thats a necessary step if you need to add freon to it. its not
gona suck in the freon unless its engaging and the problem is when your freon gets below
a certain limit the ac pressure switch sends a signal to your computer and that shuts off
your ac compressor, it does that so it doesnt damage you know, if if the freon is low it
will damage your other components of you ac system if the compressor keeps going so to
do that we are gona be using a one of these freon in a can type of products it comes with
a gauge on it that s also very helpful to have and I think i got this for about 30 dollars
plus a 10 dollar deposit at oreilly’s and you can get that too, yea I really recommend
getting this ones with the gauge on them otherwise you would need to go and buy one of these
ac manifold gauge sets and these could cost you upwards of 50 bucks, I got this for I
thing 50 or 60 bucks at harbor freight but you guys don’t need this so, you know specially
this is more for like I guess adding freon and both diagnosing the ac system but if you
are like me an you got a cheap car here and all you care about is just getting the AC
to blow cold this is all you need. So yea with that said here is how it’s done ok so
the next step is to turn on your car put the fan on the highest position turn on your AC
and make sure your AC switch is on too next you want to let the car run for a couple of
minutes than you wana check to see if your AC compressor clutch has engaged or not here
is how it looks like with the clutch engaged hopefully you guys can see and here is how
it looks like with the clutch not engaged ok so I am going to do the rest of this video
with the engine off but you need to keep the engine going if you are going to be adding
freon to it so I am doing this so you guys can actually hear what I am saying so you
know if your AC Compressor clutch has engaged you can just fast forward to towards the end
of this video since you are almost there it should be pretty easy to add freon to your
system but if your ac compressor clutch has not engaged you want to do this next ok so
if your compressor clutch did not engage you need to do it manually and you do that by
first fining your ac compressor relay and that is usually in the fuse box in the engine
bay so we just remove this cover there is usually a little guide on the cover that tells
you which one is for the ac compressor and our case its gona be this one right here so
you want to remove your relay next its kind of tricky not that tricky usually well hopefully
there is a little map at the on your relay itself that tells you which one is responsible
for the which which terminal in the fuse box is responsible for turning on the ac compressor
clutch and in our case hopefully you can see its gona be this one right here 87 as you
can see these two terminals once they get energized it connects this is kind of spring
loaded you could say but one these get energized they pull this side of this terminal (switch)
and it connects number 87 to number 30 but yea so what you can do is you can just manually
ah supply power to terminal 87 and that should turn on your ac compressor clutch and I am
just gona do that right now with some you can do it with any kind of wire or whatever
you just want to get some connect the positive side of your batter which is conveniently
located in our case next to the fuse box so yea just want to run a wire from the positive
side to this terminal which is where number 87 would go and that should turn on our ac
compressor clutch remember you want to do this while the car is running and you ac on
high ok with the car running and your ac on and the fan on the high position I am just
going to be using some alligator clips to connect the positive side to this terminal
right here and than we are gona go to our compressor and check to see if our clutch
has engaged ok now as you can hopefully see the clutch has engaged and now we are ready
to add freon to the system ok so now that we got our ac compressor clutch to come on
and engage and we can now add freon to this ac system this is going to be pretty straight
forward you basically just need to find the low port which usually has a blue cap or a
cap that just says LOW and even if you can’t find it if you find the port but you can’t
find the cap do not worry once you remove that these connectors can only go on the low
port they are pretty dummy proof so you wont be putting somewhere thats a on the other
side or you know somewhere eles that you can not or not supposed to so just remove this
cap you pull on this and you connect it like that and than you press on this and you start
reading your gauge and some of these have a dial thats you know you put on a certain
temperature depending what is the temperature outside it needs to be at a certain pressure
or psi but this one doesnt have it just has a general area guess green would be low and
as you can see the blue side if fill so if you have something like this you just want
to press it until you get it to the blue side and than ahh that’s if its low if its in the
filled area than that means you might have other problems besides low freon in your system
and you probably want to take that to a professional so you just want to get this to the filled
area and than go back inside the car and hopefully you have cold air and you can escape the heat
while driving so hopefully this video helped you guys out there if you have any questions
or comments please leave them below and if you liked this video please give it a thumbs
up alright and I will see you next time

About the Author: Michael Flood


  1. Good, but could have shown the connection to compressor terminal. I can figure that out myself, but would have been nice.

  2. I have a 1999 honda accord and when i turn on my ac it runs cold but makes my engine wanna stall . Any body know why ?

  3. Hi I added the same R134 to my 2001 ford taurus. Prior to doing so I had heat with no ac the system was workibg fine until I added the R134. Now when I turn on the fan on for ac or heat I get nothing on any settings I choose

  4. is this for the cold air in the a/c, if not could somebody help, my car isn't blowing cold air when you set it to the cold setting its blowing hoy air, i know you need to put some liquid in the car but i don't know where it goes and i don't know what the liquid is called

  5. NOTE: That clip should have a fuse incase they grab the negative trigger on that relay, being low current driver wire for the relay it will smoke it and cost inexperienced person more doa!

  6. I accidentally move one of these hose that run to radiator from compressor and lot of pressure release can I do what you did here?

  7. ok answer this when you put freon in clutch keeps running without stopping and then engageing whats wrong

  8. When the compressor clutch is running I get 35psi, when the compressor clutch is off I get 55 psi. What's happening?

  9. I replaced my condenser, so naturally the compressor won't engage because of no freon in the system. After jumping the relay and the clutch engaged and spinning, and the can connected to the low port, the can won't release any freon. It's as if the system is still closed and not drawing freon from the can.

  10. Very good information, specially bypassing the relay, I used to by pass the clutch directly to the compressor πŸ™„

  11. My 01 is300 will not take in freon tried ac pro but it wont take .clutch was working till i let a little air out of hi side,now ac clutch wont kick in either .what to do????

  12. Excellent. I suspected the compressor wasn't engaging because all the Freon had seeped out over the winter but never would have known how to trick the compressor to engage without this video. No diagram on the relay but trial and error with small wire didn't seem to hurt anything. Thanks again.

  13. This is a common civic problem and I replaced the clutch relay (fuse). I also used the exact same refrigerant and had heard this was calibrated at 75Β°-85Β° (per Amazon review). I probably was low on refrigerant and this caused the relay fuse to blow.

  14. So what if your Ac compressor switch is engaging or spinning but you cant add freon to the system. What does this mean?

  15. I was going to put freon on my car but when I connected the freon gauge it was going up and down only to the green and when it hit filled which is 45 the compresor kicks in and it goes back down to the green and repeats the process

  16. Can i reuse the hose with the gauge to read the pressure? I don't have the can attached to it anymore of course its just the hose by itself.

  17. Dear RNW you are great and you take your time to explain things well. But I have Question about my system which is confusing and I have not seen solution to it on you tube Maybe you can Help. I have Tundra 2001 it had front right side body damage affected the fender, RF headlight and air filter housing and bent the condenser, also replaced the Radiator, and fan was broken also. All were fixed. System had pressure even after accident. First situation was Low pressure low (15-20), and High pressure High over 250psi, and clutch engage and disengage frequently we added Freon just a little high side went way up and low stayed the same, pursuant to Toyota Diagnostic table, indicated Blockage in the Receiver Dryer or expansion valve, we replaced both, we also tested all the line connection for leak, after replacement and testing condenser for leak we got to situation 2. Now the condenser have minor bent but holding pressure, the low is steady normal at 40 psi, and the high side went too high 275 and kept increasing to about to 350- to 375 close to 400psi and we did not even put one small can and clutch engages all the time without stop. Do you suspect the high pressure sensor not closing the circuit and causing all of the issues?

  18. God bless you my friend i was going crazy trying to find the source i checked all fuses relays and all the wireing and they were all good till i saw all you tube videos and no responce till i saw your video and it solved my problem bypassing how you said and the clutch engaged i started add the freeon and it stayed on i just have to buy more to fill it up once again thank you very much you saved us alot of money god bless you and your family from the zapata family rocky ridge ohio

  19. i have the same gauge,when i put it on with the engine off the needle is in the alert section and when i turn the car and aircon on the needle is the low section ,any ideas,cheers

  20. I have situation when on full blast my pressure stays around 30PSI and after compressor disengages then it goes up to 60. After few min I feel cold air inside of the car but low pressure line is not getting cold. What are your thoughts on this?

  21. My car doesn't have a relay so how do I make my ac compressor ac compressor is not engaging because It has no freon

  22. DUDE,, its not FREON, its REFRIGERANT freon was a brand name of r12 that hasent been around for 30+ yrs

  23. How do you know it needs more refrigerant? Did you diagnose that with 0 knowledge of mobile a/c systems? In your driveway? With a beer in your hand? Did you check the low pressure cut out switch? How about the EX valve? Or mabe you have a restriction in the system,, or mabe your heat control door flap in your heater box isnt closing tightly allowing heat into your interior air, just a few of the MANY MANY different problems you can have in an automotive a/c system. Where did the refrigerant go? Mabe you have a leak? Dont you think you should fix that leak? So when its 100 degrees out it works well. PEOPLE DONT JUST ADD REFRIGERANT. spend the money and fix it correctly and have yrs of trouble free a/c in your car

  24. 19 year old dodge neon. Ac system never touched. Ac works fine temp wise maybe a little warmer than usual. Ac compressor at idle cuts on an awful lot. Perhaps maybe too much. Maybe a little low??

  25. Does anyone remember the GM – Buick – from early 1960s that had a small compresser pumping into a tank to be fed into engine for short boost when overtaking?
    I saw it featured in HOT ROD.

  26. Ok I recently changed my AC compressors from 1996 Cherokee Country to a 2000 Cherokee xj but i had to switch out the backs in order to use my lines. The 96 mounts in the main back and the 2000 on top of the compressor. Needless to say i lost all freon and oil. I replaced 4 oz of oil and it took it but it wont take the freon. i straight wired the clutch an it works. wont take freon. Is it full of AIR?? Did changing those backs make a difference? it worked great on the 96. All help appreciated…

  27. I can't figure out which relay is for the a/c compressor cause the legend is smeared to manually turn it on?

  28. Thanks for the tip. This didn't work exactly like the video by powering the relay input. It did however work by "jumping" the points in the cable port that goes into the evaporator. Then the compressor turned on to be able to charge the system. Hope this helps someone.

  29. You can put the can of refrigerant in a bowl of warm water and connect to the system to get the clutch to engage also.

  30. So the compressor won't come on when the freon is introduced to the system? I ask because my car's relay has 87 and 87a on the relay. (1991 Cadillac) I don't want to connect the wrong circuit and ruin something.

  31. why is it i hooked 2 different bottel s up with 2 different brands of coupler hoses and nothing goes in and nothing comes out of the hoses ? the cans is still full

  32. Be VERY careful when using stuff with the SEALANT in it, that shit can clog up the expansion valve and that is usually behind the dash and a 2-4k repair at a dealership. It is a quick fix but its not going to solve your problem. Best thing is to run dye threw the system and see where the leak is and fix it correctly

  33. So if your a.c. works but the air just isn't super cold does that mean it's already engaged and you can just add the Freon?

  34. I just want thanks all of you hew make the videos the how to fix your car or truck with out spinning a lot of money i like all of them i have been working on automobiles a long time and you never stop learning again thank you very much

  35. If the Compressor is bad will the clutch still engage? I had someone come out the other day to recharge my system and the system would not take any freon. The compressor didn't kick on, either. When I purchased the car, I was told it had a new AC compressor installed. The mechanic said I have a bad compressor. Should I try to jump it and see if the clutch kicks on, or just buy a new compressor?

  36. I drive a 1995 lexus sc400 and have found the magnetic clutch relay but now im having trouble by passing this relay there is no number 30 and 87 there the only numbers labeled for each side are 1 2 3 and 5

    Any help would be much appreciated πŸ‘ŒπŸ‘Œ

  37. If your compressor doesn't turn on when you turn the a/c on, but the belt is rotating fine, your a/c system is just out of refrigerant, and you might just have a leak somewhere. You just have to charge it and the compressor should kick on.

  38. What if your relay does not have a map for which terminal to jump? I’m asking for a 09 Mazda 3 2.3 L

  39. Not to get too technical but it is not freon in newer cars. It is R143a. (the can says that in the video as well) I'm not sure about using that stop leak. Normally they make small problems better, some of the time. Stop leak products can also do damage. I would avoid using it myself. The compressor should be running when you fill it or check the pressure. (jumper the low-pressure sensor while you are filling if you have to) Once you get a decent amount of pressure (close to charged or blue on the gauge) the compressor should run until the low side drops below a certain pressure. The compressor will likely stop while the low side gains pressure. (it will cycle but the more low side pressure you have, the longer it will run the compressor)

    Fill to the desired level and it should run constantly. The video was helpful, thanks for posting it.

Leave a Reply

Your email address will not be published. Required fields are marked *