HVAC won't turn on

[Htownag]

5th gen 4runner with trail package (no climate control). When I try to turn the AC on, the light on the AC button turns on, but after 2 seconds it's turns back off and cold air never blows. The fan does come on but no cold air.

I've tried searching for this specifically but only find similar items. Does someone know what the issue is here?

Thanks in advance

 

[RyanEJ25]

5th gen 4runner with trail package (no climate control). When I try to turn the AC on, the light on the AC button turns on, but after 2 seconds it's turns back off and cold air never blows. The fan does come on but no cold air.

I've tried searching for this specifically but only find similar items. Does someone know what the issue is here?

Thanks in advance

Did you check the freon level? I've had issues on past cars and a simple recharge was all it needed.

 

[Htownag]

Did you check the freon level? I've had issues on past cars and a simple recharge was all it needed.

Can I check it at an auto parts store? I didn't think to do that

 

[flyrv9]

Should be a fuse for the compressor - perhaps it's blown.

 

[Lester Lugnut]

Should be a fuse for the compressor - perhaps it's blown.

If the fuse were blown, there would no continuity and no green light for any length of time.

McParts places like Auto Zone cannot check refrigerant level and if they claimed they could, I would not let them do it. Find a legit auto repair shop and have them check out your system.

 

[Htownag]

*UPDATE*
I checked the fuses for the compressor and AC and both were fine. I then took it to a repair shop and they put gauges on it and there is not a problem with the freon levels. I scheduled an appointment with Toyota for tomorrow to have them check out the compressor.

Thanks for all of the replies.

 

[rigtec]

*UPDATE*
I checked the fuses for the compressor and AC and both were fine. I then took it to a repair shop and they put gauges on it and there is not a problem with the freon levels. I scheduled an appointment with Toyota for tomorrow to have them check out the compressor.

Thanks for all of the replies.

Hi Htownag,

I realize that it's getting late, but if possible, just yank the NEG cable off of the battery NOW (Tonight) it needs 4 hrs to reset and to clear out thr damaged files that are causing the problem! This will 'master RESET' everything A$$ to NUTS; I've done this procedure at least 50 times! When you start the truck tomorrow there will be NO problem with the A/C... I think (from what you posted) that the firmware just Locked up (Froze) like a WIN7 operating system.! If you're willing give it a try... you'll see it'll work fine tomorrow morning! Best to you !

rig, Cheers

 

[rigtec]

If the fuse rigtec likes this, blown, there would no continuity and no green light for any length of time.

McParts places like Auto Zone cannot check refrigerant level and if they claimed they could, I would not let them do it. Find a legit auto repair shop and have them check out your system.

rigtec likes this, rigtec likes this, rigtec likes this! and 35 others like this! ......................................Unlike

 

[socomanche]

Hi Htownag,

I realize that it's getting late, but if possible, just yank the NEG cable off of the battery NOW (Tonight) it needs 4 hrs to reset and to clear out thr damaged files that are causing the problem! This will 'master RESET' everything A$$ to NUTS; I've done this procedure at least 50 times! When you start the truck tomorrow there will be NO problem with the A/C... I think (from what you posted) that the firmware just Locked up (Froze) like a WIN7 operating system.! If you're willing give it a try... you'll see it'll work fine tomorrow morning! Best to you !

rig, Cheers

Hi Rig and anyone else that may have some insight. I have the same problem where the AC light turns on for a few seconds and then turns off. I tried the battery negative disconnect for four hours, and things appeared to reset with my 4runner, but the AC light is doing the same thing still. The interesting thing is if I don't actually turn the engine on, and just turn the electrical system on, the AC light does stay on. It still doesn't blow cold, but it is on. I don't know enough to know if it should blow cold if all is good and the engine is not on. Anyone have any input?

Thanks!

 

[83Mule]

No engine running=no A/C because the compressor is not spinning......only the fan will blow as it is electric not engine driven.

 

[EddieV4runnin]

Evaporator temperature sensor is my guess. If you have Freon, I doubt it’s the controller or the AC pressure switch. If the evaporator temperature sensor is reading too cold then it’s not gonna low operation of the AC system. It’s trying to prevent the Evaporator from icing. AC compressor is usually actuated by a relay.

 

[robr3004]

I'm have the same issue after a string of AC issues.

Last fall dealer said the compressor has a mechanical failure (AC light would blink when you pressed the button and go off). Once in a while it would actually turn on, but would only stay on for a few minutes. Dealer wanted $2300 to replace the compressor.

I waited until the March of this year and I had a local shop replace the compressor. I told them the dealer said the compressor failed and needed to be replaced. Local shop replaced the compressor, same issue. Turned out it was a bad relay. Replaced and now everything was working.

The other day, wife calls me and says the battery light, now the AC is off, no power steering. Turns out the belt broke. It actually split down the middle into two smaller belts and one of the smaller split belts snapped. Replace the belt and now the AC is not working again. Press the AC button and light comes on for 2 seconds and then turns off. Checked all the fuses and relays and they are all good. The local shop connected their computer to diagnose the issue and it says its offline. Not sure if their computer is bad, out of date or what, but they suggested bringing it to the dealer so they can read the computer and see if they can provide more info.

Another possible cause which is a long shot, but will have to check out is I found a few obscure posts about the ground wire screwed directly into the compressor was loose, but the symptoms for that was a blinking AC light which is no longer the symptom on my 2017 4Runner.

I'm going to try the battery reset today and see if that helps my issue, if not off to the Stealership so they can read the computer.

 

[Teamoatmealpie]

Evaporator temperature sensor is my guess. If you have Freon, I doubt it’s the controller or the AC pressure switch. If the evaporator temperature sensor is reading too cold then it’s not gonna low operation of the AC system. It’s trying to prevent the Evaporator from icing. AC compressor is usually actuated by a relay.

The above happened to my 4th gen- sensor out = hot air at the worst time middle of July with a 3 hour drive in a suit and tie.

I used a small independent shop who doesn't jack it's customers-


I didn't have one at the time, but a OBD2 reader has been well worth the cost to be able to know what codes are showing versus relying on the dealer for information. You can find them everywhere for under $100. You'll pay that alone for the diagnostic fee just to have the dealer plug it in.

 

[robr3004]

Update on my issue. I thought the battery trick worked, but the AC only stayed on for 5 minutes. It was unplugged for 18 hours and as stated in the steps, the truck stalled on the first startup. What I have found is that if the truck cools for at least a 1/2 hour, the AC will work for about 5 minutes.

Took the truck to the dealer yesterday to have a diagnostics run. Dealer has been awesome, they were working in it almost all day and so far only have 1 hour of diagnostic time charged out. The mechanics called me directly a few times to walk through the history of the issue. They tried swapping the aftermarket relay with an OEM, but that didn't work. Instead of charging me the $90 for the relay, they swapped back in the aftermarket one, they could have easily charged me for it. After capturing the issue on the computer, all sensors are working properly. They checked the freon and said it was slightly high, but not enough to cause this issue. One thought was there was water in the system, but when the bled off the excess freon, it's was dry. They checked the pressure of the hi and low side, with a gauge, while running and it spikes up really high just before it shuts off. I have to confirm, but they had the low side over 150psi, not sure on the high side.

They have two thoughts at this time

One, it's possible when the original compressor stopped working, it may have had an internal failure and possibly sent metal debris into the system. I still have the original compressor I'm going to drop off to the dealer this morning to see if they can determine if that is possibly true

Two, the shop that replaced the original compressor uses d an aftermarket one and they said in rare cases the aftermarket compressor was the cause.

I'm meeting with them this morning, but it seemed like they are suggesting two options. One, install and OEM compressor. Two if debris is really suspected, they are saying it's likely that I would keep throwing parts at the system and the debris will continue to cause damage to the parts and need to be replaced. With that said, a total replacement of the system comes to the tune on $4700 (22 hours labor + parts).

 

[wcslv]

Last week on Thursday my ac wouldn’t turn on. Mine is 2019 Pro and it was really humid out that night and I just could get to come on. It was late at night, so the next morning I went out and started the 4Runner and tried the ac and I started working. I don’t know what happed, but it hasn’t been a problem since. I wonder if it’s a wiring problem like a loose connection or ground. I have to check the refrigerant pressure just to see what it is.

 

[robr3004]

Dropped off the compressor and spoke with 2 Toyota master mechanics (Father and son duo). They were racking their brains last night at home trying to figure this out since they can't pin point the issue. What they came up with, based on the behavior of the pressure spiking up and then dropping and then back up again is that the compressor and compressor clutch maybe bad which is causing it stop and then work again after the pressure returns to normal. They believe if there was a blockage from debris, that the pressure would immediately spike vs waiting 5 to 10 minutes. They are going to do more testing based on that theory and also take a look at the original compressor.

 

[Captsolo]

NEW Compressor at Amazon for $200 did the trick on my 2005. Cool all summer long now - for last two years.

 

[robr3004]

Update. Dealer replaced the aftermarket compressor and clutch with OEM and its working perfectly so far. They replaced it on Saturday and let it run for several hours on and off today and had no issues and pressure is where it is suppose to be. They also added dye to the system since they needed to recharge the system anyway in case there are future problems.

They noted that the aftermarket clutch assembly has a very different design then the OEM version. They suspect the clutch was causing the compressor to run faster or slower then expected. They also believe this is was causing extra drag on the belt causing the belt to fail after only a 2 months of use. For anyone that is interested, the aftermarket brand was four seasons.