I need help with continued AC problems......

[redmanfx]

....... and I'm posting here because I've seen quite a few AC topics lately. I've recently been doing another overhaul and have replaced the AC compressor with an original Calsonic R12 compressor, Dryer, Condenser, Condenser Fan and a few other components.

The car is all back together now, but the Condenser fan isn't getting power. The relay in the fuse box tested fine but according to the 92 FSM there is another relay somewhere near the condenser fan itself, but damned if I can find it. When testing the connector that plugs into the condenser fan there is no power to it. So I need help in figuring out where my problem is there. I thought there was a ground somewhere that isn't hooked back up, but I'm sure I didn't miss something like that. One other thing is that I have an active Q that has been converted and I removed the front Pump accumulator that had a wire come down from the same AC wire harness that connects to the Dryer and connect into it, but that shouldn't have anything to do with the AC condenser fan.

The Compressor now works and both low and high pressure are fine, but there's no hint of any type of cool air and the low pressure cylinder doesn't get cold, it just gets a little cool. I ran multiple sensor test as per FSM and all come out good. How can I isolate and check the pressure control valve? Something there isn't right either so I have to test the cooling unit too. Anyway I would like some help to find my problem. I'm so pissed off after doing all that work and not having the AC work to my liking.

The Condenser and condenser fan where both busted up before they were replaced so I can't tell you they worked. The AC is doing the same thing as it did before I replaced everthing accept now the compressor works. No cold air or even cool air. The Condenser fan isn't getting power and I need to find out how to test the pressure control valve. Help!!

[redmanfx]

Can we please have this moved to the Infiniti Mechanic Forum. No one here is answering.

Thnks...

[elwesso]

Alright Redman, lets have some high and low side pressure readings, that should really help us out!! Thats the first place to start..

Test the condensor fan by shorting the relay...!!

[redmanfx]

The pressure readings were both fine according to the FSM. Nothing me or my friend(shop supervisor at the state DOT maint. yard and expert with AC systems, but not Japaneese) tried got any power to the condenser fan. Relay was fine and working. I can't say the fan motor is bad if I can't test it, but since the first one was broken before I replaced it I don't know where to start. Tracing that wire back seems like the solution, but I have had trouble trying do that. I want to know what that sencond relay looks like that the FSM says is there because it aint like the ones in the fuse box and I can't find it because it's not wear the FSM says it is that I can see!

How can I check the pressure control valve to know if it's bad? FSM doesn't go over that unless I missed something. I also checked the sensors according to the FSM and they all seem to work so short of taking this to the dealer what can I do? The Dealer in Raleigh is one to avoid!!

[elwesso]

it has to be impossible that your low and high side pressures are OK and your getting no cold air... Unless like your evaporator is messed up... your condensor fan wont come on until high side pressure gets above 250psi, at least thats what im told.....

Post the pressure readings and we'll go from there.. you should have cold air even without the condensor fan running.....!!!!!!!! Take the relay out of the condensor fan thing (under the hood) and short together the top and bottom connections, and short togethre the left and right... I used a paper clip..... The fan shoudl come on, an easy way to verify its operational state.

[redmanfx]

The high pressure was around 225psi I believe and the low end was exactly in the middle of where the FSM said it should be. I was thinking that I was getting circulation of freon fluid but nothing was getting cold. I think it is the expansion valve either stuck open or something to that effect because the high pressure didn't rise as if the expansion valve was stuck shut it just stayed the same. The evaporator is good, I believe it is, so that's all I can think of. If the condenser fan doesn't come until 250 psi (Can someone please confirm this???) that would explain it not coming on. I'll try the shorting of the relay switch to see if I can get it to come on. I've ordered a new expansion valve from Joe ($51.00).

[Q45tech]

The condenser fan also is turned on by coolant temp above 190-195F on output of rad.

[qship96]

The condenser fan also is turned on by coolant temp above 190-195F on output of rad.

FSM for 96q shows fan kicks on low speed at 203 degrees,high at 223 degrees with a/c switched "on" mine will kick on if I am waiting at a bank drive thru for a few minutes on a really hot day- otherwise,it rarely runs.

[Q45tech]

On earlier models [90-93] the fan sensor was on the output side of rad which is 10-15F cooler than the under plenum coolant sensor feeding ecu.

203F coolant sensor is roughly the equivalent of 190-195F rad ouput.

[redmanfx]

I finally got my expansion valve from Joe and have removed the cooling unit from the car. Inside the unit was a little dirty and the Evporator was dirty as well. It is a 14 year old car. That clog of pine straw looks nasty and may have had something to do with my AC not working, but I'm not the Infiniti AC man.

I cleaned it up and removed the black tar tape from around the expansion valve so I can replace it.

My question is do I need to wrap it back up in some tar tape or can I just install it back unwrapped as is? Another question. I haven't thought that the evaporator was bad because it doesn't leak anything at all and overall looks a little worn but not bad. Anything else I should look for since I've got it out?

[maxnix]

Pressure test it with a leak down test.

Good going!

[Q45tech]

Yes: You must use/replace the black insulative material IF you want to meet new oem specs.

[redmanfx]

I used the insulative tape when I put the new expansion valve on tested the evaporator as best I knew how. All tested and seemed fine. I put everything back together and recharged the system again.

I still have no AC!!! AARRGGGHHHH. Low-pressure is at 35 and the high-pressure was at 175. Odd things happened though. The condenser never got hot or warm at all, it just stayed ambient temp which was cool in temp. Both the High and Low pressure lines running to the cooling unit got hot! The air never even got the faintest bit cool or cold at all. Almost as if the compressor was going the wrong way..... I'm totally ticked off because I've worked hard to replace all this AC stuff and It's still not working. The only saving grace is that it has never worked since I've had the car, maybe for two days or so, but that's it.

The Condenser and Condenser fan were smashed and didn't work, I've replaced those.The Compressor was replaced by a new Calsonic.The Receiver Dryer was replaced. The Expansion valve was replaced. Blood was spilt for pete sakes!!

I don't know what else to do! My friend who works on cars all day long doesn't know what to do! I need some help. Never had symptom like this before. What would make both the Low and high pressure lines get hot at the firewall? Could there be a clog in the lines near the condenser or something?? Condenser never felt even warm and the fan neve kicked on.

[Q45tech]

When you used a flush device [with correct flush hydrocarbon] to clean inside the consenser and evaporator did black death come out?

The oem [from dealer] Calsonic compressor come with new flex lines or did you secure a compressor without new lines.

[redmanfx]

You could say it was black yes and I did not change all my lines, just some of them. When the freon was transfered back and forth however it wasn't all black or anything. What's the black stuff in the evaporator, carbon deposits? Does that mean the evaporator is bad? Before I got the car I couldn't tell you how long it had been since the AC worked, so I'm just going by what I know from what I've changed out already.

The compressor is R12 not the newer R134a, so I didn't get the upgrade; the one with the flex lines. All still original OEM from 92 from what I can tell.

Please don't say I'm doomed with my system. I'm not giving up on it yet

[Q45tech]

BLack Death is the compressor seals and the insides of the flex hoses after they react withi ACIDIC OIL created from R12 and moisture and the old oil.

In the case of a wreck this can ocur as the system violently decompresses then sits dead for awhile.

My primary question was you did flush and examine the output flush hydrocarbon for residue.

When the compressor fails, the BD ciculates out and plugs up the condenser and is hopefully stopped by receiver dryer [not always the case].

[redmanfx]

Apparently I did not check good enough. I did see residue and thought it was cleaned pretty good though. I can't tell you what the cleaning fluid was, but it was for Car AC equipment. My friend uses it on all his AC stuff that he fixes. I'll tell you what this AC is a pain and very time consuming for me to tinker with, not to mention all the freon needed for it. If I had the money I'd take it somewhere to be someone else's problem to fix...

At least I learn allot from doing it myself and will be able to help others with there AC questions if it comes to that. I guess I have to go back in and remove the Evaporator again... This car keeps beating me over the head.

[maxnix]

AC is probably even more critical than under pelnum hoses to refurbish entirely and correctly or suffer compromised performance, early failure, and repeated labor. No shotcuts allowed, or you are doomed to repeat history. Again and again and.....

[redmanfx]

The more i think about it the more I think the Evaporater is fine and the condenser is shot. The used one I bought was,...well used and probably didn't work that well. I'll have to check the dryer to see if it got gunk in it and re-replace my condenser. That'll be my next step.

[maxnix]

Save yourself some grief and do the hoses and O rings too.

[redmanfx]

Now my blower won't turn off. Right at start up it's on and it won't turn off, no matter what setting I select or even though the climate control is "off."What the HEY!! This started 2 days ago and I've removed the neg side terminal from the battery, but that didn't reset anything. Arrrggghh... I'm getting tired of this. Like a teenager rebelling in it's youth...

[Q45tech]

WE pointed out that eventually to make an AC new you have to change everything.

When the fan motor ages [the evap dirt shows the age] and draws too much current it pops the fan speed controller.........or it got electrically discoed or you blew the HVAC computer by discoing the battery ground while engine was running [alternator].

Fail Safe is to run fan wide open to tell you what happened.

[redmanfx]

Ran with fan wide open and all the controls from the Climate control worked fine (changed speeds, changed vents) except for the off. Actually it did turn the climate control off but the fan kept blowing and switched to the bottom vent. I know for a fact I only disconnected the neg battery post when everything was off including the car, so that couldn't have caused my current issue. Now I'm going to get an evaporator and another condenser(in much better shape).

What can I do to stop the blower fan from running? How do I check the HVAC computer? What would T-3 charge me to install an evaporator and condenser and get my AC working??

[Q45tech]

Not really worth it to drive to ATL for simple AC rehab..........Just bring your Q45 FSM to a local [Bigger city NC] expert.

Make sure the connector is plugged into fan speed controller socket.......if discoed it will act like a module failure.

[Q45tech]

Not really worth it to drive to ATL for simple AC rehab..........Just bring your Q45 FSM to a local [Bigger city NC] expert.

Make sure the connector is plugged into fan speed controller socket.......if discoed it will act like a module failure.