www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW MKIV-A4 TDIs (VE and PD)

VW MKIV-A4 TDIs (VE and PD) This is a general discussion about A4/MkIV Jetta (99.5-~2005), Golf(99.5-2006), and New Beetle(98-2006). Both VE and PD engines are covered here.

Reply
 
Thread Tools
Old July 13th, 2018, 07:32   #1
Couleetdi
Veteran Member
 
Join Date: Aug 2003
Location: West Wisconsin
Fuel Economy: 65/52/47
Question 2003 Jetta TDI Manual A/C Not working

A/C unit blowing warm air, no cooling whatsoever. My son was driving me to Dr. office when it happened.

I was reading last night everything I could to find solution, including my Bentley manual. Here is what I've found so far with great difficulty.

I have hairline fracture in right leg, just below top of fibula. Wearing full leg brace, so doing anything "sucks". If you ask how, daughters 120 Rottweiler/Mastif mix 2 yr old puppy knocked me down. Cute dog, doesn't know his own strength yet.

Diagnosis: Checked with Fluke 77 DVM
Battery fuse box fuses 180 and 164 I think they were are fine.
Fuse locations 5 and 16 on side panel are good,

With key on, AC button depressed, and fan set on 2nd and later full on, both cooling fans run fine. Do not hear A/C clutch kick in.

Layed on floor in garage, no easy task here, unplugged wire connector to A/C unit, turned key on, AC button on, fan on, got like .87 vdc. Started engine, and did same.

I am assuming, that with the fans running the FCM is probably good, but guessing, as I have no A/C experience. First time in 40 years I've had an A/C problem.

A/C clutch is probably bad, just guessing.

With leg in brace for another 6 weeks, I won't be doing this myself, and driving is near impossible with full leg brace. I do have Vagcom but not sure if it will help diagnose anything AC related.

Would appreciate any ideas to assist me. Won't take it to local VW dealer, that's a joke. Not sure if anyone locally in western wisconsin is good.

Thanks All,

Coulee
__________________
2003 Jetta TDI Stock ! Green 5speed Vented
AVG MPG 50+ and improving
Couleetdi is offline   Reply With Quote
Old July 13th, 2018, 09:22   #2
alex_tdi
Veteran Member
 
Join Date: May 2001
Location: Los Angeles, CA
Default

Have you checked the pressures yet?

You can rent a A/C manifold gauge for FREE at Autozone. It looks like this: https://www.autozone.com/test-scan-a...set/326077_0_0 There are plenty of youtube videos on how to check/fill the A/C for the MK4.

One thing when checking/filling R134 is not to turn the manifold quick connectors all the way down, just turn until you get a pressure reading and then a little more. My A/C recharge valve uses a "ball valve" instead of the more common Schrader Valve with a pin that looks like your tire valve. See https://www.impalaforums.com/attachm...c-port-017.jpg

These old school "ball valves" like to break and leak if you turn the connectors all the way down. If you see "bubbles" around the black ball, then you need to get them replaced. Don't spend $50 - 100 at the dealership, get both for $10 at Autzone: https://www.autozone.com/cooling-hea...kit/947268_0_0

With luck, you're just low on R134. If so, you can take it to an A/C shop and have them evacuate and recharge with R134. Alternatively, you can recharge yourself buy monitoring the pressures with the aforementioned A/C gauge. First option is the official and best way. Second is the quick fix that will confirm you just need R134 and get the system going before getting it recharged properly.

Good luck and let us know how it turns out.

Alex

Last edited by alex_tdi; July 13th, 2018 at 09:29.
alex_tdi is offline   Reply With Quote
Old July 13th, 2018, 09:52   #3
Genesis
Veteran Member
 
Join Date: Feb 2003
Location: Niceville, FL
Fuel Economy: 53/48/42
Default

You have to be pretty low for the safety switch to cut out on low pressure. If you're THAT low you have a decent-sized leak (over half your refrigerant is missing!) and need to find it.

It's also possible the pressure sensor itself is bad, however, or the wiring to it is. It is not a switch so it can't be tested with a simple continuity test. VCDS will tell you what duty cycle it's reading though. The most-likely place for a leak is the compressor shaft seal since it's a rotating part. Next up are the O-rings at the line connection points and the seals at the service ports. A little bit of UV dye in the system (readily available) plus a hand-held black light will quickly find leaks if you don't have a refrigerant leak detector. DO NOT use refrigerants with sealants in them; they will work for a little while at the cost of ultimately destroying your compressor.

These units HAVE TO be charged by weight, not pressures. If you (for whatever reason) don't want to have an A/C shop pull vacuum and recharge from zero, and still have pressure (in other words the unit has NOT been exposed to ambient pressure and moisture) then an alternative is to get a set of gauges and charge until the high side is double ambient in Fahrenheit + 50 psi and the low side is around 30-35psi. If EITHER SIDE goes out of range while doing that *STOP*. Possible causes of that are a restriction in the system, quite possibly in the dryer since the service port (and pressure sensor) on the high side are both AFTER the dryer and there is no pre-dryer service port to check, or the RCV in the compressor (or the compressor itself) is bad.

Note that if you ever run into a variable-displacement system like this with one high-side sensor that starts cycling off and on (like an American car that is designed to do so) odds are you have a serious restriction in the condenser or dryer. DO NOT add refrigerant -- it's not low, the system is clogged up and the high side is being sucked down through the TXV stacking up all the refrigerant in front of the restriction!

There is no safe way to charge these systems (or any other with a TXV, which basically all modern refrigeration systems have) without gauges on BOTH sides. You can be safe and reasonably accurate using pressures and superheat temp calculations but the only truly-accurate way to get the correct charge is by weight.

Last edited by Genesis; July 13th, 2018 at 10:02.
Genesis is online now   Reply With Quote
Old July 13th, 2018, 11:59   #4
jrsride2002
Member
 
jrsride2002's Avatar
 
Join Date: Apr 2013
Location: Houston, TX
Fuel Economy: 48.07 <> 47.03 @ 70mph ~2400RPM's
Default

Quote:
Originally Posted by Genesis View Post
... it's not low, the system is clogged up and the high side is being sucked down through the TXV stacking up all the refrigerant in front of the restriction!
Genesis,

I am in a similar boat. But my simple question is. If the TXV pressure is that high. Wouldn't that kind of build cause a fuse to blow?

I don't know the AC system enough to do the job. I just am trying to fix everything, for when I go back to the shop. I'll have a working AC.

Thanks for your knowledge,
~Junior

Sent from my SM-G892A using Tapatalk
__________________
'03 Jetta Wagon GL TDI M/T - RIP
'02 Jetta Wagon GLS TDI M/T - She's ALIVE!!!!
jrsride2002 is offline   Reply With Quote
Old July 13th, 2018, 12:08   #5
Genesis
Veteran Member
 
Join Date: Feb 2003
Location: Niceville, FL
Fuel Economy: 53/48/42
Default

The system on the ALH at least goes thus:

Compressor -> Condensor (where heat is rejected) -> Dryer -> High side valve and sensor -> TXV -> Evaporator -> Low side service valve -> Compressor

So if the dryer is clogged you will see LOW pressure on the high side AND low side service ports -- all the refrigerant is in the condensor, hose and dryer! The VERY low pressure on the high side will cause the ECU to disengage the compressor, the pressure will equalize, then it will turn back on. But since no oil or refrigerant is actually flowing it won't be long before the oil in the compressor overheats, cokes and then you're done.

If the TXV is clogged the high side pressure will be SOMEWHAT high (the RCV in the compressor will keep it from going ballistic-high and blowing up something or opening the case relief valve) and the low side will be *extremely* low, perhaps even in vacuum. Again with no refrigerant or oil flowing the oil in the compressor will overheat since there is no actual flow of refrigerant through the unit to cool it, it will coke, and again, you're buying another compressor.

In both cases you *might* think the charge is low and add refrigerant -- doing so will make the problem worse and might liquid-slug the compressor which, if it happens, will destroy it.

In both cases, if there's a restriction and you shut the system OFF you'll find the pressure on BOTH sides is reasonably normal (typically about the outside temperature in fahrenheit, so on a 90F day it'll be somewhere around 90psi.) If you find that pressure is normal with the system off the charge is *not* low enough to cause a lack of cooling. Maybe a bit down on cooling capacity, but not incapable entirely.

Most American and Japanese cars are designed to cycle on and off and have no variable displacement capability in the compressor itself while most European cars are designed to vary the compressor displacement instead, with some models having no A/C clutch at all (they run close to zero displacement -- just enough to circulate and keep the compressor cool) when the A/C is turned off.) The ALH uses a mechanical valve in the compressor, newer models use an electrically-controlled valve that can be replaced without opening the unit up, but in both cases you have to recover the refrigerant first.

You just can't reasonably diagnose these things without a set of gauges for both high and low side. And if there's refrigerant in there you also can't legally get it out of there to make the system safe to work on it without taking it to an A/C shop to have the system pulled down because it's illegal to intentionally vent it (the stuff is pretty nasty if you breathe it too!) Whatever you do don't put the Walmart special stuff in these systems that have leak-sealants and similar in them; that stuff is just like a radiator sealer and is basically guaranteed to clog things up inside. If you have a leak you need to find it and fix it; the UV dye stuff is not a bad way to do it, and a handheld UV light (which also works on coolant leaks, incidentally) is cheap and ought to be in your toolbox anyway.

Last edited by Genesis; July 13th, 2018 at 12:16.
Genesis is online now   Reply With Quote
Old July 13th, 2018, 19:17   #6
red16vdub
Veteran Member
 
red16vdub's Avatar
 
Join Date: Aug 2013
Location: (617) City of CHAMPIONS
Default

Quote:
Originally Posted by Couleetdi View Post
A/C unit blowing warm air, no cooling whatsoever.

Diagnosis: Checked with Fluke 77 DVM
Battery fuse box fuses 180 and 164 I think they were are fine.
Fuse locations 5 and 16 on side panel are good,

With key on, AC button depressed, and fan set on 2nd and later full on, both cooling fans run fine. Do not hear A/C clutch kick in.

Layed on floor in garage, no easy task here, unplugged wire connector to A/C unit, turned key on, AC button on, fan on, got like .87 vdc. Started engine, and did same.

I am assuming, that with the fans running the FCM is probably good, but guessing, as I have no A/C experience. First time in 40 years I've had an A/C problem.

A/C clutch is probably bad, just guessing.



Thanks All,

Coulee

Iíve been here before and
If you check all this ^^^ then Iím 99.9% sure you need a new compressor.
You can however replace the AC clutch magnet and coil, but considering the year of vehicle itís best to just bite the bullet and change the compressor.



Bajan
__________________
Mk1 Gti /scIROCco 16v /A6 quattro sport / Mk4 TDI JSW 5spd
17/56 turbo, RC ASV-5+ @ 28psi, 3 Bar Map, 11mm IP, PD Lift Pump, R520's, McNally boost/egt, Euro FIS full screen Cluster, PD 150 Intake/racepipe, PD 150 plastic T.I.P + R32 maf air mods, Kerma 2.5" Fmic, Kerma 3"T-B exhaust/resonator/ Aero turbine muffler, SBC stage 3 Endurance, GLi brakes F/R , GLi axles, H&R Bilstein sports cup kit.
red16vdub is online now   Reply With Quote
Old July 13th, 2018, 20:00   #7
TDI-WNC
Newbie
 
Join Date: Jun 2018
Location: WNC
Default

Every time my A/C has filed (the vehicle make doesn't really matter), it has been a low freon charge. If the pressure is too low, the system will not engage the compressor. There is probably nothing unique about the AC system in 99% of the vehicles on the road.



If gauges show there is sufficient pressure within the system, then start electrical trouble shooting.


In a 15 year old vehicle, has leaked down to the point the compressor doesn't engage, it just may need a charge which likely would last for years going forward, as is the case on my pickup truck.
TDI-WNC is offline   Reply With Quote
Old July 13th, 2018, 20:47   #8
AndyBees
Veteran Member
 
AndyBees's Avatar
 
Join Date: May 2003
Location: Southeast Kentucky
Default

For what it is worth, about two weeks ago, I installed a new "used" AC compressor on my 2000 Jetta. After everything was in place and almost an hour evacuation, I turned the ignition On, fan On, and AC button in (On). Then, I began adding the refrigerant. About two thirds in on the first can, the Fans out front kicked On......... then in about 30 seconds or less, they kicked Off ....... then almost immediately back On. Then, by the time the 1st can was in, the fans stayed On. So, the pressure switch obviously affects both the Fans and Clutch coil via the ECU and FCM.

As for exact amount, I do agree Genesis. However, considering the AC info sticker generally provides an amount with a + or - (plus or minus) that's equivalent to as much as a 10% swing in volume, I do believe you can get in the ball park then in side the ball diamond if you are very observant as you gas it up. You definitely need a set of Manifold gauges. Without manifold gauges you will be totally lost as to what's going on with your AC system. Genesis has provided some extremely good info for diagnosing problems with your 2003 Jetta AC system.

My 84 Vanagon with an ALH engine and the AC compressor that come on it (SD 7V16), I have no choice but to "guess" at the amount of refrigerant it needs (R134a). With manifold gauges, 80 to 85 ambient, I get about 225 psi high side and about 40 psi low side and low 40f out the vents. Temp changes and/or air flow on either side (condenser and/or evaporator) will significantly change pressure readings that can without a doubt be observed on the gauges. Example, to aid in the process of putting in the refrigerant, I use a box fan to blow on the condenser out front. Turning off that fan will immediately cause the pressure to go up on both sides but proportionally more on the high side.

Hope this contributes to you solving your problem!
__________________
'84 Vanagon '02 ALH TDI engine Malone Stage 1 tune. CAT, SS 2" exhaust, E-vac system, DMF with upgrade pilot shaft, 4.57 R&P, fan assisted IC. (32 to 35+ MPGs consistently)

Last edited by AndyBees; July 13th, 2018 at 20:50.
AndyBees is offline   Reply With Quote
Old July 13th, 2018, 22:46   #9
rrgrassi
Veteran Member
 
rrgrassi's Avatar
 
Join Date: Jul 2006
Location: Royse City, TX
Fuel Economy: 46 city 53 hwy
Default

All good info! Also agree with not using the stop leak stuff. It is a polymer that harden when it comes in contact with air. Lots of compressors have an engineered leak on the front seal to keep the seal lubricated. Guess what happens when that stop leak hits that area...
__________________
RRGrassi

06 Jetta TDI BRM 248K
03 Golf TDI ALH 380K+
90 Dodge D250 Cummins 12V 400K
rrgrassi is offline   Reply With Quote
Old July 17th, 2018, 19:09   #10
jrsride2002
Member
 
jrsride2002's Avatar
 
Join Date: Apr 2013
Location: Houston, TX
Fuel Economy: 48.07 <> 47.03 @ 70mph ~2400RPM's
Default

Hey dude.
Just learned a little trick that will help you with the drier.
When you disconnect it, clean the surface area with rubbing alcohol. Then apply painter's tape, to seal the open port. That will keep the drier sealed while you have the hose off.

Learning little tricks like this is so rewarding!
~Junior

Sent from my SM-G892A using Tapatalk
__________________
'03 Jetta Wagon GL TDI M/T - RIP
'02 Jetta Wagon GLS TDI M/T - She's ALIVE!!!!
jrsride2002 is offline   Reply With Quote
Old July 18th, 2018, 03:16   #11
Couleetdi
Veteran Member
 
Join Date: Aug 2003
Location: West Wisconsin
Fuel Economy: 65/52/47
Default

TY to everyone for their idea, suggestions and help on the AC issue. Finally took off full leg brace, drove to town and check pressures. Solution, yup Compressor shot. 15 years old car.



Checking basic things were no problem, learned a bunch from all of you. Thanks again


coulee
__________________
2003 Jetta TDI Stock ! Green 5speed Vented
AVG MPG 50+ and improving
Couleetdi is offline   Reply With Quote
Old July 18th, 2018, 04:17   #12
Genesis
Veteran Member
 
Join Date: Feb 2003
Location: Niceville, FL
Fuel Economy: 53/48/42
Default

BTW here's a tip on that -- go get a high-side service port (they just screw in and are common on basically every car made that uses R134a) and have it in your toolbox. They use a little rubber ball rather than the older tire-style valve core in the R12 systems, and that ball likes to disintegrate over time. If you want to be proactive just change it when you have the system empty -- they cost something like $5 -- but be aware that what looks like a locknut on the line IS NOT one and if you think it is and crank on it you'll destroy the hard line; counter-hold the line at the bottom hex and unscrew the port from the VERY TOP, it is NOT in there very tightly (it's O-ring sealed like everything else.)

If you discover the ball has disintegrated when you detach your high-side gauge snap-on adapter and all the refrigerant leaks out out you're going to be rather unhappy if you don't have another one to replace it with, especially if you wind up with a zero-pressure system (again!), this time for a couple of hours to go get a new port (or worse, if there isn't one in stock locally and the system is thus depressurized for a couple days!) and thus wind up replacing the dryer (again!)

Last edited by Genesis; July 18th, 2018 at 06:25.
Genesis is online now   Reply With Quote
Old July 18th, 2018, 07:41   #13
KrashDH
Veteran Member
 
Join Date: Dec 2013
Location: Washington
TDI(s): 2002 Golf
Default

Quote:
Originally Posted by Couleetdi View Post
TY to everyone for their idea, suggestions and help on the AC issue. Finally took off full leg brace, drove to town and check pressures. Solution, yup Compressor shot. 15 years old car.



Checking basic things were no problem, learned a bunch from all of you. Thanks again


coulee
Before you say your compressor is shot, have you or are you willing to open it up? These compressors are pretty robust and most times when you open it up all of the valves still look fine as well as the head, unless the thing has been neglected, the system has developed moisture internally, etc.

The RCV valve internal to the compressor is known to go bad. I troubleshot my system a while back and it led to this. Just a heads up, it's like a $15 part that's worth a shot over a new compressor.
KrashDH is offline   Reply With Quote
Old July 18th, 2018, 16:59   #14
hollowhead
Veteran Member
 
hollowhead's Avatar
 
Join Date: Jul 2015
Location: cope,sc
Fuel Economy: 40ish beetles, 52 wagon
Default

What were your pressures?
hollowhead is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
AC Not Working 2003 VW Jetta TDI ianradcliffe43 TDI 101 5 June 16th, 2018 10:46
2003 TDI Jetta Wagon Manual TDIdw TDI Cars for Sale/Wanted 8 September 16th, 2015 14:57
2003 Jetta TDI Manual for sale danhr TDI Cars for Sale/Wanted 5 June 8th, 2014 13:19
What's the value on my 2003 Jetta TDI Manual filfy TDI Cars for Sale/Wanted 8 April 9th, 2012 20:47
2003 Jetta TDI Wagon manual. TexasTodd Private TDI Items for Sale/Wanted 5 July 27th, 2007 20:44


All times are GMT -7. The time now is 08:05.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
© 1996 - 2017, All Rights Reserved
Page generated in 0.17859 seconds with 13 queries
[Output: 133.05 Kb. compressed to 112.55 Kb. by saving 20.50 Kb. (15.41%)]