Hi you guys, good day to you! Welcome back! I See a Jeep Grand Cherokee So let us see if you can see what I see and what I see is no AC stopping Z Engine Let's see here. let's get our thermal probe in there customer. States Uh AC Performance is lower than expected or underperforming or both. So uh, we're gonna do a system evaluation on this bad boy.

See what the deal is? See if the AC is going to work appears to be making some fold I can feed it Let's uh, let me nose this thing in a little bit and let's throw the machine on there. take a look at the system, see if it's operating as designed, and then we're going to go from there. So stay tuned because this is going to be a very cold video opening. Z Hood All righty Coming around to the business end of this unit here, we can see that the compressor is compressing, she's on, the clutch is engaged.

Let's see, we're missing our cats for our service boards. high side there and look aside there. this cap looks like it's been gone for a while. There's a there's a bunch of corrosion and whatnot down inside of that hole right there.

Um, let's see. let's check for our fan. Looks like it looks like our fan is running. Is this a hydraulic fan? Yeah.

Looking like straight right down right there that looks like a power steering line going to this giant fan motor assembly. Hang on. I Think this is a hydraulic fan? That's it. Something like that.

In a while. You know? let's crawl down here and take a look. Hey, what do you know? Look at that. It's a hydraulic fan.

Yeah, there's the solenoid that actuates it. We've got our lines, our return line, and a couple little fluid leaks here. Interesting. Looks like the steering gear has a leak.

or a couple leaks. Maybe that oil filter? There's some fluid? Hmm. Well, our issue is the AC and I think this Fan's turning a little bit too slowly. Let me Go Fetch the machine.

Uh, we'll check the pressures and then we'll go from there. But I think we're running. uh. pressure to the Moon Before you do all that, let's go back into the cabin and recheck the uh.

the thermal meter in the dash okay dash meter says we're making what's that say? about 70 degrees? 68 survive somewhere in that zone? Okay, so yeah, we're We're definitely underperforming. Let's uh, let's go grab the AC machine and see what kind of freshness we have. Come on Robinair machine, you're coming with me. Mark That right there.

Okay, what I'm looking for is high side pressure going through the moon. So we'll get this. connects to our high side service board now. I Understand this truck's had some AC work done to it before.

Maybe some recharges or something, so it should. It should want to function like, uh, it's not I mean it does work, but it underperforms. Um, get this one plugged in. Okay, what do we have here? Pressures look decent.

a little low? yeah. I'm gonna do what I normally need to do is I'm gonna go ahead and recover this. make sure that the refrigerant charge is within specification, powering on, and then, uh. well.

we're gonna go from there. Maybe the maybe we do not have a fan issue I Hope we don't have a fan issue because that's a really, really expensive fan here. Guaranteed. Okay, Machine is powered on.

Uh, we're gonna go ahead and recover everything foreign. So it's going to evacuate all the refrigerant, it's going to put it in the storage tank, and then we're going to be able to weigh out firing down. We're going to weigh what we recovered and compare that with the specified amount. and that's going to let us know if we were under charged, overcharged, or charged just right.

I don't know. 0.3 pounds The little undercharged. What is our spec? Where's our placard with our Ac refrigerant spec on it? Um, no, not that one. No No No No no no, not on the firewall.

Okay, I'll look it up. the service data coming back in. look at that point. Nine one, nine pounds.

so it is a little under charge. Okay, now like I mentioned, this low side service port valve was a little crusty looking due to having been exposed to Atmosphere with no cap for a while. So as per my normular protocol, since I've got the system discharged I am going to go in there and replace these valves. Let's go ahead and pop this guy out of here.

Come on valve. They're a little tough to dig out. There's a vacuum in the line so air pressure is kind of holding this thing in. Let's see what this guy looks like here.

Yeah, it's a little worn at the seal. It's tough to see if that seal is pretty depressed. Okie Dokes We got a new unit here. Drop that guy Down in the Hole and we're gonna tighten her down.

Come on. Schrader Bell Hurry up thick. put our service hose back on or can I maybe I can't get on there. Thank you of course.

Uh, I won't neglect the high side service valve. I will replace that one as well. That's a big one. Okay, so here's our new unit.

That's our old unit and we can see that the O-ring at the valve at the bottom of this one has been squished and it's flattened. So we're definitely going to drop in our new one right here. That's why I Always like to, uh, replace these guys. You just, you never know I've had brand new ones fail.

They just don't seal 2023 Quality Control? What are you gonna do? Or 2022 Quality Control? Or it's 1984 Quality Control? Who knows I don't know. fighting that just a wee little bit with the pliers. That's how we found it. Good to go and put our hose back on.

Okay, so now we know we've got good valves in there. Let's go ahead and put this thing under a vacuum. recover out all of the air that we introduced by opening up the system. I'll install a little bit a little bit of dye in this thing and then uh, we'll charge it and then see how it performs 10 minute leak test.

Go Go. Actually, I'm gonna cheat and Skip ahead of half of a step. So right now we do have a vacuum going on, but it's only vacuuming the high side. I'm going to go ahead and install the die into the low side of the system if I can get this clipped on.

Come on you? Yeah, definitely not getting that one-handed. It's a finicky little valve there, so what we do is I'll just turn this little cylinder. it's threaded on the inside and we'll inject a slight amount of dye. There we go.

Okay, now we can see that there's a bunch of green dye kind of hanging out. I'm going to wash all this out of here so it doesn't deceive us in the future if this thing turns out to have a leak and we rely on the die to find it so we don't want any residual dye, just kind of hanging out here. We want to get all that washed away. Oh I Forgot there we go.

Okay, okay, this thing is nearly finished evacuating. Got about 30 seconds left on it. We'll let it finish up and then we're going to go ahead and install the charge. All right, let's give this thing its charge.

I Did shoot some oil in it with some dye or under vacuum. This is good. It's been holding vacuum. This is also good.

It also had pressure that tells me that there's no huge leaks anywhere. There could be a leak, but, uh, not a huge one. We're looking for 1.687 pounds refrigerant and we want to do that. I'm going to shoot that in on the low side because put some dye on the low side and that initial blast of the refrigerant going into the system will help disperse that die.

No side charging. Let's get rid of these uh, these old valves. We don't need those around anymore. It's another one that's an old one.

You're getting charging now please. Lowest Side refrigerant. Go! Go Go. Thank you.

All right, we're headed in. Let's let this charge and then we'll restart the system and uh, see if we have any pressure or temperature change and pressure change. Actually we were seeing like the 150 160 pounds on the high side but we were also at like 60 70 chart. Something like that I Didn't do the math but it was low on a charge but the pressure was still the same.

So with the proper charge in the system, we may experience an event where pressures are a little bit higher than spec. You know, 252, 75, 300. that can be caused by low flow over the cooling package. Okay, we're at 1.6 pounds refrigerant in the system.

I'm gonna go ahead and uh, start this thing back up and kick the system back on restarting the engine. Okay, we've got airflow. Our temperature is starting to come down. We're about 75 right now.

Let's go out and check the pressures. We'll check the machine that we have here. look at that. our high sides a little bit higher, low sides a little bit higher.

That's still within specs so we're okay here. Let's see. Let's go ahead and hose come up and see press supports for those compensate. This is a board post.

Compensation is what's going to happen is the machine is going to install into the car a predetermined amount of refrigerant based on weight and that predetermined amount is calibrated to the volume of refrigerant that is contained within the hoses. So as it sits right now, it installed 1.687 pounds refrigerant, but some of that is still inside the hoses, so it's just going to add a little bit extra to displace what's in the hoses and make sure that the system is full to its maximum capacity. Whatever. Yeah, okay, pressures are creeping up a little bit.

That's a little high for what we're looking for. It's not a very hot day today. Let's go and check. Uh, check.

Check the thermometer in here. and yeah, we're about the same as where we started. Even though we had a low charge, the system's underperforming. Let's Uh, I'm gonna throw some fans in front of this thing and we're going to get some airflow artificially created over the cooling package.

and we're going to see if our temperature is inside. drop down. and we're also going to see if our high side pressure is. Drop down is what we'll do.

We'll move this thing right here to create a nice little stand for us. Then I came out. Get the fan on board here, see if this is gonna work there. We go.

Okay, so we're still sitting at the 225 230 250 Zone Power up our fan. Full Speed Ahead We have airflow. You can't see if you can feel it our high side gauge. it's going to start to do.

We may need more fans here here. Let's get the Big Shot fan out. We'll squat it down so it is in line with our Hood Lock that in and tote this bad boy over to our truck. Okay, Fan powering on.

Take a look at our pressures before we, uh, before they change what we have here. look at. that pressure's going down. It's not even very good airflow, it's just kind of here.

It's not really directed. Let's turn it on high. Fan on high. Still seeing that pressure drop.

Yeah, that's pretty good. Now, just for the sake of science. I'm going to shut down the fan again. We should see that pressure rise.

Oh, look at that. Yep, pressure's going up. Fan back on again. Pressure is going down.

Okay. let's let all this stuff run right here. We're gonna go inside and recheck the center fence Dash Temperature. Right now.

we're where are we at. 65 for a while and we'll come back and check it in a moment. Okay, jumping back in. Uh, we're down to 60.

still very much underperforming, so let's apply some process of elimination. We know our charge is good. We know that our compressor is good because it is making pressure. We know that our metering device is good because there's a pressure differential.

We know we have a problem with airflow because we're attempting supplemental airflow, which is effective, but not as effective as the shrouded fan that's already contained in the car. So we need to, actually, uh, go ahead and work on this airflow issue and make a move to get the proper flow over this cooling package. And that's going to be. well.

that's going to require us to diagnose the issue with this hydraulically actuated power steering pump driven fan. So there's two parts of this system. There's the well, two primary Parts there's the mechanical Drive hydraulic section and then there's the electronic actuator that tells that the hydraulic motor down there to to go ahead and pick on. So what we need to do is get to the connector which I believe is this one right here a little red guy and check and make sure that that's receiving its pulp.

Swift modulated signal I think it's PWD signal. You have to make sure it's receiving a signal. Turn on the solenoid to actuate the hydraulic pump. So let's go ahead and do that right now.

What I need to do is remove that little uh grid safety tab locking mechanism there actually I see to pull this whole thing out so I can manipulate it. That's probably better. Unflip that unfit. There we go.

and let's check this for the meter to make sure we're getting our signal down to the uh, the solenoid that's on the car. All right multimeter. Let's set this up for voltage real quick. Like we'll do a quick check on our meter to make sure it's going to function green to Black We're going to go ahead and just ground.

and actually we don't even need a jumper lead to stick that guy right in there and we've got charging voltage. Okay, leads are good on the meter. I Always test my test equipment. come.

Here 's our connector. Nothing, nothing and we've got voltage here. Okay, Got power being run down to that solenoid. We have voltage.

Let's check our ground side. So I'm going to assume that that black wire is ground. Go ahead and probe that one. I'll move my meter round over to the hot side and we've got voltage there.

so we have a ground, but what we don't have is that fan coming into high speed. We've also got signal at that Center wire, so that tells me that I have an issue down south with that solenoid or the uh, the actual motor itself has failed, which I find that somewhat unlikely. So I'm gonna go down to that solenoid and we're going to check everything at the solenoid because there's still this lead wire right here that may have an open circuit in it if we can disconnect that solenoid back in. Okay, all right, back down below.

looks like it's my lucky day. There is a connector down here at this solenoid. See if I can't fish that guy out real quick. getting a little warm in here? Come on.

I can't get it too dangerous. Well, I'm just gonna shut this down. Yeah, too hot, too dangerous firing down. Going back in.

Okay, I've got it disconnected again. I'm down here with the meter and what I'm gonna do is just recheck for all those voltages right down here just to make sure that there's no break in. The Wire Okay, I've got signal here, signal here and let me switch the Uh the lead over and we'll check the signal on that last circuit there standby and we've got power on. Well, that pin right there.

I Just had a flashlight hit me in the face. That sucked. Okay, so now that leaves us to conclude that the issue is right around here somewhere, which is why we do not have high speed fan action. Now we can see this fan is running even though it's disconnected because there is fluid flow running through this unit.

What I'm going to do is plug this in and I'm going to feel it and I'm going to listen for the audible click which is going to tell me that that solenoid is closing if we do not get the click. I can conclude that that solenoid has failed. So let me get in there and whoa, hang on, hang on, Hang on Coming alive. Let's disconnect again and see.

I Think the fan just kind of kicked on? Perhaps we have a faulty connection here. Fans slowing down I Feel less airflow? Okay, maybe we just had a corroded corrosion in that connector. which I Do see some up there in those pins? Let's plug her in again. Oh yeah.

Oh yeah yeah yeah. Fans on. Now it's live. All right.

Let's get out of here and recheck our system performance one more time. It's getting warm down there down to 175 with a full charge and we heard that fan coming on. This is good. Now we're getting some flow.

Let's go into the cabin and check our temperatures at the vent still at about 60. Okay, let's give it some throttle. I've been watching the gauge up front, don't know if you guys can see but we're uh, we're at about 200 pounds at 2000 RPM temperature slightly falling for about 60. still a little six, it's still right at 60.

let's hold it for a minute. All right. this is interesting. So I'm noticing that my uh, my flow here is not very strong.

Okay selecting through some of these modes and I Just heard one of the doors go hear that there's a broken door inside of the dash. See now our temp is climbing again. select it to the floor. The noise back there stopped.

still have flow here so our Mode door is not operating. Pick up the temperature and see if our our temperature blend doors are working. You know I'm still cool air. Okay so we're set to high and high.

We're still at 60 degrees on the center vent. It still has Air at the center event but I've got it. selected the floor. select it back over to Center or in your face fence.

Still not getting hot so we have uncovered yet another problem. so let's recap real quick before we keep going. We had a low refrigerant charge that was corrected. We had a fan that wasn't Fanning that was corrected and now we're on to the climate control section inside of the cabin where the blend doors are not working so the temperature door is not working and the mode control door is not working because it doesn't select between modes and doesn't go between hot and cold.

So I think it's probably stuck somewhere in the middle. Sort of recirculate works I didn't hear that one either. Okay, well let's stick our heads under the dash and see what I can come up with down there. Okay, so I think we're done up here with the uh, the mechanical side of this system.

It's all working. The Fan's still going I am going to go down there and disconnect that connector one more time and clean the corrosion off of those pins. Pretty sure that had something to do with it powering down. Let's get this guy out of the way and uh, see I wonder if I have some cats? they're gonna fit on me.

That's a negative on that one. Let's try this one here. Thank you and that one doesn't fit, but this one does okay. that's an improvement also.

Okay, here's what: I'm gonna do this right here. This is our mode selection knob. That's the one that goes from you know, off auto and then can change uh which vents you have activated. We're gonna go down there and we're gonna find that mode control door and I'm going to reach up and actuate this simultaneously.

but we're going to watch to see if that mode actuator is running or not. So bear with me, we're going back into a dash. Okay, so that right there is our mode actuator that, uh, a device there and then it's got its cams and all of its linkages. So I'm gonna reach up and around to that knob and we're gonna run this unit and see if it's gonna work.

Okay I don't know what position I'm selecting I'm just going through all the positions at the time. Okay, it's working I Did feel an airflow change down here at the bottom fence. All right. So the mode actuator is working.

Now that doesn't mean that it's changing the airflow because there could be like damage to the steel inside of the evaporator case which makes this horse a different color. Um, let's go to the other side and try temperature control and see if that actuator works because although we're getting I Mean we still should be getting cold and we're really not getting that much cold. I mean 60 70 degrees? This is It's underperforming. which leads me to wonder if temperature control is is not working.

Where Where will I find? We'll see it down there. Let's take a look uh, behind our glove box here. Maybe it's hiding Avalanche Um yeah, there we go. What's that about? Okay, does that one work? I'm turning the knobs and it's not doing anything I wonder if that's the recirculation actuator? That's a big negative and something is broken in the dash.

Okay, see that someone has disconnected this and now it's sitting there hanging out. But we can see when we try to actuate this manually, nothing happens. So the door inside of the HVAC unit is broken all right. So I've gone ahead and turned off the fan.

it's on low so the system's still running. but I've turned it off just to illustrate what else I found here Gravity Found some flashlight gravity All right. So if we look up here inside of that little Grill you can see one of the doors inside of the HVAC box. Now that is the Mo.

I'm sorry the recirculation door so that's the one that'll if you open it, it'll bring in air from the outside and if you close it, it'll recirculate air which is already in the cabin. I'm going to select that actuator and we're going to see if the research system operates which. I don't hear it and I didn't hear it earlier, it's selected off no activity selected on new activity flashlight and again I don't hear that actuator functioning either. Now we know that the door inside of here is broken because that should not be freely spinning in a it should have a lot of resistance on it and taking a closer look we can see that somebody at some point has had this HVAC box out and has disassembled its unit Because if we look right here, you see that.

see that fatigue in the plastic and the bend in that little tab. plus all that space right here. somebody's had this box out and apart before. Um, there's some damage going on in there.

So uh yeah, this is going to require uh, quite a bit of work to actually make this right. We need to pull the dash back out of this thing. so this is a little bit more than what I thought it was okay. So I'm going to go ahead and let my guy know what I found and I guess we're gonna go from there I may suggest that he allows the last person that works on this the opportunity to correct their error.

Um, otherwise he has to pay a second time and that would be unfortunate because this is, uh, this is going to be an expensive repair. Oh, look at here more. Uh, more of that binding and fatigue. See that How that one's bent down? there's a wire sticking out of this one? I don't know if that goes there or not.

Maybe it does. Maybe it doesn't. That's not correct. Yeah, yeah, somebody somebody broke something in here.

This is not good. Okay, yep. so Dash has to come out and the HVAC box has to be broken into again. It probably needs new doors.

Um, it probably needs new actuators. I'm not really certain. but uh I know I Stopped here so I'm gonna go ahead and close this video out. Our diag is complete.

There's nothing more I can do so. That being said, as always like thank you for watching this video. Hope you enjoyed this extensive diagnostic cooling system video. If you did enjoy this video, please let me know about that by tapping that like button down below.

If you did not enjoy this video then um, well let me know about that in the comment section down below and maybe I can use your feedback to do a better job. So again and as always, thank you for watching and most importantly, do not forget to have yourselves a great day! See you guys later! End of cheat for now you.