List of Useful Threads Complete 2nd Gen A/C Troubleshooting Thread

[TheJackal]

I began doing this because we always get asked the same questions, but can never find the threads. I forgot about it and found this when I was cleaning off my computer. Now that the A/C season is here, it could be helpful to a few people.

The Blend Door Issue
Before you blame the Blend Door, or the almost equally troublesome Blend Door Actuator, put the A/C into "Max A/C" mode and turn the fan on high. If you still aren't getting cold air from the A/C while in "Max A/C" mode, then you don't have the blend door problem.
If you get a "click click click" sound it could be the Blend Door Actuator.

If you do suspect a blend door issue, see these threads:
http://www.explorerforum.com/forums/showthread.php?t=214332
http://www.explorerforum.com/forums/showthread.php?t=193991
http://www.explorerforum.com/forums/showthread.php?t=59787
http://www.explorerforum.com/forums/showthread.php?t=212667
As you can see It's a very common issue.
Blend Door Actuator Part Numbers
EATC (Electronic Automatic Temp. Control, you have this if you have digital A/C controls)
--Dorman part #604201
Manual Temp. Control (you have this if you have knobs that control the A/C)
--Dorman part #604202

Blower Motor Only Works on High
This appears to be a common issue as well. It usually means your Blower Motor Resistor or Speed Controller is dead. Before ordering, remember there are 2 different parts--a resistor for manual A/C controls (knobs), and a "Blower Motor Speed Controller" for electronic A/C Controls (EATC--has a digital readout like a radio does). They're not interchangeable, so make sure you get the right one! Sometimes people say they smell something burning before it stops.
See here: http://www.explorerforum.com/forums/showthread.php?t=193997
^Some part #s in that thread, don't know if they're right or not^
http://www.explorerforum.com/forums/showthread.php?t=216963
See also BrooklynBay's List of Useful Threads, Item #55.

Blower Motor Works on all settings Except High
Don't hear this one often, but if it does happen it usually means the "High Speed Blower Relay" is bad. It's located in the Auxiliary Relay Box 1, which is located in the engine compartment on the passenger side, near the air filter housing.
http://www.explorerforum.com/forums//showthread.php?t=252928

Blower Doesn't Work at All with EATC
Blower Motor Speed Controller
http://www.explorerforum.com/forums//showthread.php?t=266568
Also see above "Blower Only Works on High"

A/C Compressor Does Not Run when "Vent" is selected
The A/C compressor isn't supposed to run when the knob is turned to "Vent." :

A/C Compressor Does Not Run in Any Mode
It could either be low refrigerant, or a bad low pressure switch. See below for checking system pressure.

Rear Air Issues
I don't have an Explorer with the rear A/C, but from the diagrams I see it doesn't appear to be complicated. There's no A/C or heater plumbing involved; the rear air operates only when the front A/C or heat is on and gets air from a duct under the dash. So, if you're having trouble with the rear air, it's entirely an electrical issue, and remember that if the front A/C or heat isn't right the rear won't be either. There's a blower motor, resistor, and relay under the console that controls the airflow out the rear vents.
Like the main Blower resistor, this can also be accompanied by a burning smell.
The rear A/C is completely different on 3rd Gens and up.

Vacuum Issues
"Air only blows out of the defrost vent."
Vacuum leaks can cause problems like the A/C blowing out of the defrost or floor vent, either intermittently or all the time.
Things to check include the vacuum switch (A/C control unit), vacuum reservoir (black ball in passenger side fender), as well as checking the vacuum and vac lines. Get your head behind the dash and listen for any unusual hissing sounds.
http://www.explorerforum.com/forums/showthread.php?t=192842

A/C Compressor Bypass Belt
You can bypass the compressor with a shorter belt; useful if the compressor is seized.
If you have a V6 engine, you should be able to use the belt for an Explorer built without A/C.
If you have a V8 engine, see the threads below for using the Duralast 835K6 belt from AutoZone:
http://www.explorerforum.com/forums/showthread.php?t=161318;
http://www.explorerforum.com/forums/showthread.php?t=217676
Bypassing the compressor clutch pulley versus just driving with the A/C off doesn't result in any measurable performance or fuel economy difference.

Measuring A/C System Pressure
If we think your issue is related to a refrigerant problem, we'll ask what your pressure readings are. In order to get a proper pressure reading, you should use a manifold gauge like this one:

See http://www.explorerforum.com/forums/showthread.php?t=158183 to learn how to use a manifold gauge.

Where are the High and Low Service Ports?
A picture is worth a thousand words...
http://www.explorerforum.com/forums/showthread.php?t=221770

R-12 vs R-134a
R-12 was used in auto Air Conditioners prior to the mid 90s. R-134a has been used since then.
You need different equipment depending on which you have, and you cannot mix them.

R-12 is more expensive and difficult to find since it has been Banned in the United States and other
countries. If you want to convert to R-134a, you should have a professional do it. See here:
http://www.explorerforum.com/forums/showthread.php?t=77331

96-98 Accumulator Refrigerant Leak Issue
Refrigerant leak in late model Ford Explorer? Check under the accumulator blanket!

---

Hopefully this information helped you think of some questions you'll need to ask when you start your A/C related thread. The more detailed your descriptions and questions are, the easier we'll be able to help
you.

 

[aces_dad]

Great post! I have this issue:

A/C Compressor Does Not Run in Any Mode
It could either be low refrigerant, or a bad low pressure switch. See below for checking system pressure.

I've measured the pressure (bought a refill can with a gauge), even without adding anything the pressure is well into the acceptable range. I'll try to change the low pressure switch. Is it not possible the high pressure switch is bad as well?

thanks! AD

 

[TheJackal]

Could be. Do you know the high side pressure?

 

[aces_dad]

Hi Jackal,

I didn't ... I was unable to locate two pressure switches so I just replaced the one I had easy access to. By tracing the route it sure looked like it came from the low pressure side, but, I was only able to find the part with the description low/high pressure switch.

FOUR SEASONS Part # 20054
Category: A/C High or Low Side Pressure Switch

Here's a pic

And after replacing it my AC works! Thanks a lot for the debug guide, it was a very simple repair once I had the new part. Just an FYI if anyone else with a 2004 Explorer tries to get this part, none of the local shops carried it, so I ordered it online from rockauto.com.

 

[Joe Dirt]

Great compilation...

 

[TheJackal]

yah usually it's the low pressure side that goes.

Glad it helped!

 

[4rd Xplora]

yah usually it's the low pressure side that goes.

Glad it helped!

I'm on board to do this tomorrow thanks to you. Just finished a complete re-build of the A/C system yesterday had the system vacuumed and recharged today and the compressor will not come on. BTW can this part be changed without blowing the charge? If this turns out to be the problem the first round's on me, Jackal

 

[aces_dad]

4rd,

According to the documents I've found, at least 02-05 Explorer low pressure switch is equipped with a Shraeder valve and will not blow the charge.

 

[4rd Xplora]

4rd,

According to the documents I've found, at least 02-05 Explorer low pressure switch is equipped with a Shraeder valve and will not blow the charge.

You are correct! And Jackal....1st rounds on me

 

[lancecordero]

i have a 06 ford explorer limited edition and my rear a/c does not blow out cold air, but it does blow out what ever the temperture is out side. When i put the rear heater on, it works fine also the front a/c works fine

 

[lancecordero]

i have a 06 ford explorer limited edition and my rear a/c does not blow out cold air, but it does blow out what ever the temperture is out side. When i put the rear heater on, it works fine also the front a/c works fine

 

[Magicland]

Can anyone verify that the Dorman 604-201 actuator works on a 97 with EATC? Every place I check shows it listed for 1998-2001. If I do a search for my vehicle, I get the 604-202, but that lists manual air, and I've definitely got EATC in my Eddie Bauer.

 

[HiImElvis]

Great Thread!! Thanks for collecting all this in one spot. Do you know the correct High and Low pressures that should be observed in the A/C system?

 

[lopezge]

4rd,

According to the documents I've found, at least 02-05 Explorer low pressure switch is equipped with a Shraeder valve and will not blow the charge.

I think my low pressure switch has gone bad on my 2004 explorer XLT and the dealer says that when replacing the switch it will blow the charge. A $365 repair with vac and recharge. True or not?

 

[aces_dad]

The new switch cost me $28.15 from rockauto.com. No loss of AC. If it didn't have a Shraeder valve I wouldn't have felt comfortable doing the job myself.

 

[1AJeremyD]

Im pretty certain that all r-134A vehicles are equipped with a shraeder valve and lopezge that sounds like a fair price for an A/C job. Least their not going after something like the compressor or something, then your wallet would be hurting.

 

[NUFX]

Blower Motor Only Works on High
This appears to be a common issue as well. It usually means your Blower Motor Resistor or Speed Controller is dead. Before ordering, remember there are 2 different parts--a resistor for manual A/C controls (knobs), and a "Blower Motor Speed Controller" for electronic A/C Controls (EATC--has a digital readout like a radio does). They're not interchangeable, so make sure you get the right one! Sometimes people say they smell something burning before it stops.
See here: http://www.explorerforum.com/forums/...d.php?t=193997
^Some part #s in that thread, don't know if they're right or not^
http://www.explorerforum.com/forums/...d.php?t=216963
See also BrooklynBay's List of Useful Threads, Item #55.

Most likley I think the Motor Resistor is most often the culprit in such cases where either the fuses are either grounded or there are negation on the wiring. Indeed, I have seen like you pointed out confusion between the Knobs for manuals and BMSP's for electronic ones.

 

[Kriegen]

Having a bit of problem with my AC. It worked excellent back in the summer but now it's not putting out any cold air and the when on Max AC, the compressor cycles on and off every 5 seconds or so. I've checked the pressure on the low side with an idiot gauge(colors that show undercharged, properly charged, over charged, about to blow up...) When the compressor cycles, the pressure gauge will change from being at the top of properly charged to the bottom of properly charged but always in the range of properly charged.

any suggestions?

Thanks

 

[kgabrielsen]

Where are the switches (low and high) located? Anyone post a picture for a 94 V6 EB?

 

[Limey2471]

Ranger A/C repair issue...

Looking for some help...96 ford ranger 2.3L Splash...i found a leak on the high pressure valve on the A/C...this was not a repairable item so i got a new. At the same time i replaced the accumilator, all o-rings and the high pressure switch along with the clutch cyc switch...i pulled a vac on the A/C system for about 30min...then let it sit another 30min for leak test...All good...filled the system to specs and verified on a/c guages all good. Here is my problem...while truck running in drive way a/c on to max all looks good...if i increase the RPMs...then the a/c clutch starts to engage/disengage and will keep doing it and the engine sounds like it could stall. If i shut the truck off and start again all willl be back to normal till i increas the RPMs...any help or thoughts...Oh i also replaced the WOT relay..it seems a low idle there is not enough power to run the compressor