2002 Honda Civic - No AC - Compressor won't turn on

2002 Honda Civic complaint of no A/C. In this video I go through various checks and electrical tests to verify the A/C compressor and checking the whole control path. This one has a bit of a twist at the end...
If you have a Honda Civic that you're having A/C troubles with then feel free to drop a comment below!

[@sergiochavez9725]

Thank you so much! Had spent hours checking things under the hood and didn’t know much about wiring. This solved the problem and I learned lots of things. Thank you

[@husseinlodhee2357]

The only video I have seen on You tube with great explanation..I have the same problem on my Honda jazz..Not solve up to now..Module change..Resistant ..But same problem persist..Thanks..Merci.

[@survivingga]

Great video. I was diagnosing a no a/c with zero repair info and you covered the circuit so we'll, I managed to make it through it. Mine ended up being a Multiplex Control Module.

[@noahmurillo6048]

Can I get the part number for that or a good name for what your talking about to search up

[@noahmurillo6048]

Please and thank you ?

[@noahmurillo6048]

Was you getting a no ground on the ac compressor relay ?

[@johnmichaeltampoya6052]

​@@noahmurillo6048 same problem with me, don't have a ground on the AC compressor relay, and my AC switch button won't turn off. it always on

[@fernandovillegasduarte9383]

Excelente explicacion. Gracias.

[@Doc54117]

👍🏽climate control is coming on the blower is coming on. This video is helpful because the compressor wasn’t receiving power and the fuses relays good 100% helpful 🤷🏽‍♂️

[@eurbanautotech]

If you're ever having trouble telling if a relay is good or bad I posted a short video that might be helpful! :D kzbin.infoo_x_W2zBq-Y

[@alanflores6555]

Helppppo please my is no getting power to the compressor

[@x1lightningman725]

Hello, Thanks for the Video. I found some of the information very helpful. I have 2004 Honda Civic ex coupe. Same exact situation. A/C always blew very cold. Then the car sat for a year. A/C wasn't working after that. I figured it needed a charge. But that did not fix it. I did some troubleshooting. All fuses were good and checked all the wiring good. It is not clear to me. Are you saying that the HVAC fan was working, like for heat; but somehow the controller module wasn't seeing a signal from the fan module and therefore not turning the compressor clutch on? I ask this because my fan works fine for heat and circulation. Please clarify this for me. Thanks so much. I appreciate your help.

[@justinhodges7711]

okay so this was super helpful, but i followed along everything you did and my car was exactly the same in every aspect until you text voltage on. the blue wire behind the module, i got 8 volts and when i tried to ground it out like you did with your test light, my compressor still didn’t kick on. any idea?

[@martinarrieta248]

Grasias

[@yt-itzluckygamer8537]

So a bad ac module can cause ur ac compressor to not kick on??

[@michaelmendez9423]

Hey wondering if you can help me out a bit Bought this 03 civic a year ago and ac wasnt ever cold but I could see the compressor was still engaging…slowly got less cold and then finally to the point the compressor doesnt engage anymore so Im guessing its low on charge and pressure switch doesnt allow it to engage(i dont have guages but I just pressed in the schrader valve and barely hear any pressure). So ive checked the fuses and checked relays(put the relays where the relay for the horn goes and checked to see if it worked. Would this suffice for checking the relays?) jumped power at the relays and clutch engages and condenser fan works. Tried bypassing the pressure switch by grounding it out how you mentioned in an other comment but does nothing. I want to test everything to see if it works before I go recharge the ac… should I just recharge it now and hope for the best or is there anything else I should test? Kinda dont wanna fix my ac if its gonna cost more than a couple hundred bucks lol

[@michaelmendez9423]

Also still trying to make it through your video but im getting overwhelmed with info😵

[@eurbanautotech]

@Michael Mendez I hear ya on the not wanting to spend tons of money. A/C can be unpleasant like that. From what you're describing sounds like you have a leak. Maybe not a massive one. If you were to get the system charged up it might last the summer. You might even get two summers out of it but I doubt more than that. Sometimes finding leaks can be difficult to find and expensive to fix. Most common leaks I've found are compressors, condensers, the hoses right at compressors and the schrader valves. The schrader valves are at least cheap and easy to fix! But ya, chances are you have a leak. You'd probably only hope to get one season out of a charge and leaks tend to get worse over time. Just by saying the system was blowing cool then slowly got less cool then stopped engaging the compressor at all is enough for me to be satisfied that everything's working as it should electrically and mechanically. If it just suddenly stopped working one day then maybe look at some of the controls. But with the gradual decline then nothing... you're good on the control side. Pulling the relays and placing them in the horn to check them isn't just "sufficient" ... it's *excellent!* I'm going to have to start mentioning that idea! Haha. My advise is see if you can find a small shop that's reasonable and will work with ya. This stuff can get expensive. I've worked at plenty of larger shops that EVERYTHING is a cost. 1) "Diagnose" A/C not blowing cold (basically just confirm it's not working) 2) Evacuate&Recharge 3) Nitrogen pressure test 4) More time to look for leaks ... hopefully found it by here ... ... perform repair ... 5) ANOTHER evac&recharge Becomes a money trap. You start feeling like you spent so much money on the diagnosis that you're "committed" to fixing the system. It literally only takes 5 minutes for an experienced tech to put a set of gauges on it, see that your pressure is too low for the system to turn on, then do a quick check of the common spots with a UV black light. We would not charge for this. I'm sure there must be other shops out there that would also be willing to do this. This would be a super quick check in the parking lot. No putting the car up in the air. No removing splash shields. Only looking at what you can see from up top, through the grille or if you can see anything on the ground. Definitely not a definitive check but helps ya get an idea of where you stand. Otherwise what you could do is use some top up cans and see how long that lasts. Definitely make sure you get some with UV dye in them to help find leaks. Just a warning about top up cans though. If you're in the US then you can get actual R134a refrigerant in those cans and you're all good. If you're in Canada (like me) then you can't. They are only "substitutes". Some shops won't work on cars that have that stuff in them. Or they'll charge extra. But if you can get cans that say R134a and not R134a *substitute* then you're golden. Good luck!

[@michaelmendez9423]

@@eurbanautotech ok so I was able to recharge it and I found the leak on one of the main aluminum lines near the low pressure schrader valve where my hood prop was rubbing against because I dont have the clip that holds the hood prop. Now im starting to think I might actually have a bad switch? The ac button which I assume sends power to relays because I can engage the compressor and fans by jumping power( with refrigerant in I was able to get cool air now) but when i press ac button the compressor isnt engaging or the condenser fans turning on. And I dont think it would be a bad pressure switch because I would be able to bypass it which it doesnt work still also not a bad thermo overload? Because the compressor would disengage even after directly jumping power to the relay right?? Either way dont think ill end up fixing it as I plan to sell the car anyways but would have liked to have some ac during its last summer in my hands LOL. Thanks for the help I greatly appreciate it

[@michaelmendez9423]

@@eurbanautotech also should the schrader valve be producing bubbles as well or is that a leak or is it just happening because of the leak so close to the valve?

[@eurbanautotech]

@Michael Mendez Hey there. Sorry about the late reply. I'll try to address all your concerns here. As far as the bubbles at the schrader valve go, those are perfectly normal after you detach your equipment from it. It'll leave some residual refrigerant/oil behind that'll boil away and evaporate. Totally normal to see that for 10 seconds or so. Not normal to continue seeing that for MINUTES. The schrader valves are very prone to leaking. Especially if they get depressed for the first time after sitting in the same position for a long time. As far as the controls go this system has a rather unusual setup. There is the HVAC control unit on one end and the fuse box control unit on the other end. The HVAC unit puts out a ground which goes through the pressure sensor AND the thermal overload switch in the compressor then goes back to the fuse box control unit. If EITHER the pressure sensor or the thermal overload are open then the ground will not make it to the fuse box controller and the fuse box controller will not turn on the compressor relay. The HVAC controller will only put out a ground if it is satisfied with its conditions. As in the evaporator temp sensor is reading normal, the blower fan is working, etc. Both the pressure sensor and the thermal overload need to be good. The wiring needs to be good. The fuse box controller needs to be good. The A/C compressor clutch relay needs to be good.... A lot of variables in these systems...

[@danishzd]

If your blower was working on other settings, wouldn't the AC then work at higher blower speed?

[@chrisramos1525]

I just got my compressor change 2 weeks ago , now it’s not blowing cold air anymore

[@elkilo3008]

My A/C on my 2003 civic stopped working out of no where when i got out of work , all fuses are good i tested the blower and does work but there’s no air blowing out.

[@eurbanautotech]

Chances are it's the blower control module. The pulse width modulated version of the old school resistor pack. Everybody calls them different names. It's a solid state transistor pack that controls the blower speed. It gets very hot and will burn out over time. It'll be a 4 wire connector under the dash by the blower motor. Just make sure to inspect the terminals of the connector as they like to burn up too. But they're easy enough to get and change so not the end of the world. If you just wanted it done and over with then I'd say just throw a new transistor pack in. More than likely that'll get you fixed. Just make sure the connector is fine. If you have access to decent wiring diagrams and you like electrical diagnosis then they're not terribly hard to go through and diagnose fully. I did have one go on a Jeep Liberty that I'm in the process of making a video on where I go through everything but that'll probably be a few days away. In the meantime if you wanted to do more testing I could guide you in the right direction. Just let me know. And good luck!

[@xeptur]

Any clues on my issue my ac has freon and blows cold but only when I’m driving at idle blows hot air

[@eurbanautotech]

I would suspect your rad fans are not working. The A/C system absorbs heat from inside the vehicle into the refrigerant via the Evaporator. For the system to be able to work it needs to have a way of removing this heat so it can absorb more and keep blowing cool. It does this via the Condenser in the front. In order for the Condenser to work it needs to have air flow across it. When you're driving down the road that air flow is provided by the movement of the car. But when there's no airflow from that it needs to spin up the fan(s). If the fans are not working then the whole system will not work. The Condenser also needs to be free of dirt, leaves and other debris. But if that were the case you probably wouldn't have A/C when moving. It's a good idea to run a garden hose through the fins. NOT a pressure washer... Garden hose with some soapy water is good enough. Start your vehicle with the A/C off then get someone to turn the A/C on while you're watching the fans. They should turn on pretty much right away.

[@johnmichaeltampoya6052]

same problem with me, don't have a ground on the AC compressor relay, and my AC switch button won't turn off. it always on

[@cesarromeroacosta4781]

Buenas noches líder yo tengo un problema así en mi honda civic 2002 lx qué primero era cuando el aire se apagaba y resolví eso era la resistencia qué tenía un falso contacto ahora el compresor no arranca no se si sera frion o ese problema del modulo

[@alanflores6555]

Lo arreglaste ?

[@anthonythornton4249]

So the issue was the blower motor module and not the climate control module itself?

[@eurbanautotech]

Yup. The blower motor "resistor"/module was faulty. Because of this the HVAC module wasn't putting out the request to turn on the A/C compressor. So the ECM never new A/C was selected and never turned on the compressor. I wouldn't have guessed an oldy like this '02 Civic would have that kinda control but yup.

[@anthonythornton4249]

@@eurbanautotech your video is much appreciated. I was running into the same issue and followed along with your troubleshooting. Ended up replacing the Climate Control Module and everything works now. Thank you!

[@eurbanautotech]

@@anthonythornton4249 Awesome. Congrats on your fix. That is one of the main reason why I decided to make videos. I work at a small shop where it is just the boss and I. I certainly don't miss working at large shops but I do miss interacting with others and helping others through struggles!

[@erlynlegaspi3316]

Short story the problem is climate control module.. Same problem my honda civic 2001.. Thank you

[@eurbanautotech]

@erlynlegaspi3316 This one was a faulty blower control module (resistor pack).