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View Full Version : 2006 NAG1 sprinter blowing warm air w/ A/C switch on


eschaton
06-01-2011, 07:04 AM
Help! I have a 2006 Sprinter NAG1 w/ the A/C blowing warm air even w/ the A/C switch turned on. I thought perhaps it was just too hot in the ambient temperature. Left the A/C running for about 5 mins and it was still blowing warm air. I read somewhere that it is a good idea to check on the R-134a refrigerant level/load before proceeding further. My question is:

Where can I find the A/C's low pressure valve to plug my arctic freeze gauage on to check on the load level? A picture would be helpful as I am not mechanically inclined.

P.S. The other exact same 2006 Sprinter's A/C clutch/fan would engage whenever I press the A/C button there. Not this one. Called up both local Dodge and MB stealerships. Both want anywhere between $190-230 for leak test by putting dye into the system. I don't want to shell out that much money just for the leak test when I could use the arctic freeze's gauge to find out first on the level of refrigerant.

Any help would be greatly appreciated.

Thank you in advance.

Type2Teach
06-01-2011, 01:59 PM
Where can I find the A/C's low pressure valve to plug my arctic freeze gauage on to check on the load level? A picture would be helpful as I am not mechanically inclined.

Sorry, don't have a picture, but I can tell you where mine is ("02). I just checked it a few days ago. It is located above the negative battery terminal.
There seem to be a few different fittings that look like they could be it, but if you have an A/C pressure tester, the fitting will ONLY fit on the correct one. At least that has been my experience.
If the fan isn't kicking on, that indicates to me it's an electrical problem. Again, this is just based on my limited experience with A/C systems.
Have you downloaded a manual? Search the forum for a manual. It may give you more help than I can.
My A/C is blowing sorta cold air, but when I checked the pressure the other day, it was very high. I have to look into this. My wife and kids are starting to complain... :thumbdown:
Good luck and keep the forum posted.

eschaton
06-01-2011, 02:57 PM
Thank you for the reply. I remember that I saw a metal tub very close to the vehicle's main battery w/ a green label that says "A/C" w/ MB's logo. As you and the Arctic Freeze can w/ pressure gauge suggested, the pressure gauge only fits into the A/C low pressure valve. I can't possible mess up anything. As soon as I have the van back this evening, I'm going to check it out. This A/C problem must be resolved soon. We just had the Memorial wkend and we are already getting 80s here in the Northeast.

Type2Teach
06-01-2011, 04:33 PM
here in the Northeast.

Where are you?

eschaton
06-01-2011, 07:07 PM
CT. I see that you are in PA. Hello neighbor. I just downloaded the 2006 Sprinter Service Manual from another thread. Very cool, technical and informative. I only read the section pertaining to the front A/C (ours have no rear a/c in the passenger compartment.

One quick question: As I read on page 24-78, Fig. 16 Receiver-Drier, on the 2006 Sprinter Service Manual, it shows the A/C Liquid Line (Front section) and (Rear Section). I just want to confirm that the "Front section" is indeed the "high-side service port" and the "Rear Section" is the "low-side service port" of which I would connect the Arctice Freeze gauge to check for refrigerant level. Can anyone please confirm for me before I mess up anything? Thanks.

bc339
06-02-2011, 02:35 AM
Yes, you are correct. The High pressure line is smaller diameter, with the service port by the front end of the batery (positive terminal). It has the large port. The low pressure line is larger in diameter, the dervice port is on the line at the firewall - its got the smaller port. Connect your gauge and R-134 to this one, the low pressure line at the firewall. If it's a typical recharge hose with gauge, it will only fit the low pressur port.

Bruce

eschaton
06-02-2011, 02:28 PM
Ok. Just hooked up the refrigerant can w/ pressure gauge into the Low-side service port. It read 15PSI based on the ambient temperature of 70 degree. It was low. So, I added more refrigerant and checked pressure level until it reached approx. 38PSI w/ the ambient temperature of 70 degree. Did all these while the engine and A/C was @ max cool/speed. Continued to let the A/C running afterwards for another 10 mins. PSi held up (didn't expect it would drop even if somewhere is leaking since 10 mins wasn't long enough to really tell much - certainly not on the ground...). A/C was still blasting out warm air. Somewhere must be wrong. My question is:

- Vehicle is under extended warranty. I want to minimize downtown and avoid the stealership to jerk me around. Is there anything else I could check w/ my trusty multimeter WITHOUT taking anything out BEFORE I bring the vehicle into the local Dodge shop this wkend?? Please advise.

Thanks!

bc339
06-02-2011, 05:14 PM
Did the a/c ever engage after you added R-134? Check to see or hear if the a/c clutch is engaging - the a/c compressor and the aux electric fan should have started cycling once the pressure came up. The expansion valve - some call it the H valve due to its shape - may be stuck if it's still hot.
One of the features of the DAD is that it will display the high and low pressures, switch operation and outlet temp while operating. Without it, you'll have to use the proper a/c servicing gauges to check the high and low sides for troubleshooting as well as an ohm out the pressure switch. You should be able to insert probe wires into the a/c pressure switch to see if the circuit is working.

Bruce

Type2Teach
06-02-2011, 06:15 PM
One of the features of the DAD is that it will display the high and low pressures, switch operation and outlet temp while operating.
Bruce

Really? Man, I learn more and more about the DAD every day! Awesome!
Thanks!:thumbup:

jmoller99
06-02-2011, 10:04 PM
Check your fuses. My air conditioner blew only hot air until I cleaned the contacts on them (I had added R-134 also). The Sprinter has poorly gripping fuse holders.You have fuses under the steering wheel (large door there) and also on the door side on the bottom of the car seat.

light sandpaper works fine for cleaning the fuse contact surfaces.

eschaton
06-02-2011, 10:56 PM
@ Jmoller99: Cool. I only checked the fuses under the steering column and didn't check the ones under the car seat. I'm going to check there in a few minutes. Thanks!

15 minutes later from the above reply: Checked the fuses under the driver car seat. All fuses had this yellow masking tape on all of them. I guess the MB folks knew that the fuse holder is not secured just as you described. Anyhow, I removed all masking tapes. Pulled, visually inspect testing each fuse. They are all good! I reapplied electrician tape over the same area instead afterwards to make sure nothing is loose. Btw, I did the same procedure for the fuses under the steering column and they were all good as well.

Any other thoughts?? I replied to BC339 earlier that I don't have the DRBIII or similar scan tool as some of you guys. The service manual says that A/C pressure transducer can only be diagnosed and tested by using the scan tool. Does this mean I need to bring the Sprinter into the shop now since I have done all the preliminary testing/confirmation as a normal homeowner can do??

eschaton
06-02-2011, 10:59 PM
@ BC339: I'm going to refer to the service manual and find out where the A/C pressure switch is so that I can probe it w/ my multimeter. To answer your question if I heard the clutch engaging while I pressed down the A/C "snow flake" symbol. The answer is a resounding "no". Going to probe the A/C pressure switch soon once I figure out where it is from the service manual.

@ BC339: A few minutes after I posted the reply above, and read the service manual. Quick question: Is the A/C pressure switch the same as "A/C pressure transducer" as used in the service manual? If so, the service manual says that the transducer can ONLY be diagnosed and tested by using the DBRIII scan tool (I'm sure others would jump in and said there are other tools out there to do the same thing or even better). I'm just a homeowner w/ the multimeter. Any thoughts??

bc339
06-03-2011, 12:59 AM
Really? Man, I learn more and more about the DAD every day! Awesome!
Thanks!:thumbup:

It's under special functions, Data stream, HZR Live Data, four pages of data available.

eschaton - Since your Sprinter is still under warranty, a dealers DRB scan of the system would probably be the best course.

Bruce

P.S. - you could probe the transducer through the top of the connector - brown wire is ground - then compare with the voltage table for the transducer.

P.P.S. - Found the wiring diagram on page 8W-42-4, ground is brown with black stripe, 5 volt supply is red with black stripes. the feedback wire is brown with red stripes. You'll either have to make three jumper wires from the connector to the transducer to connect your meter or use a needle probe since the wires are pretty well sealed at the connector.

Dougflas
06-04-2011, 01:22 AM
Full charge is 1.9 lbs of r134a. So that is approx 1 lb 14 .5 oz. Not that critical because the drier holds some excess charge. You can be off an oz or two. If charge is very low, low pressure switch will be open and compressor clutch will not engage. Look at the front of the compressor to see if clutch is engaged. First thing to do is remove the battery cable in case computer is locked out. If you have a scan guage (DBRIII or DAD), you'll want to check for codes first. If no scan gague is available, you can remove battery cable but you'll lose any stored codes. If you only had 15 psi you probably have a leak and the system locked you out.

eschaton
06-06-2011, 12:48 PM
Full charge is 1.9 lbs of r134a. So that is approx 1 lb 14 .5 oz. Not that critical because the drier holds some excess charge. You can be off an oz or two. If charge is very low, low pressure switch will be open and compressor clutch will not engage. Look at the front of the compressor to see if clutch is engaged. First thing to do is remove the battery cable in case computer is locked out. If you have a scan guage (DBRIII or DAD), you'll want to check for codes first. If no scan gague is available, you can remove battery cable but you'll lose any stored codes. If you only had 15 psi you probably have a leak and the system locked you out.
I checked the psi on the a/c system early this morning before driving the van to the dodge stealership 40 mins away (waiting @ the dodge now for them to look @ the van). It was @ about 17psi!! So, I guess the leak was not noticeable wihtin 2 hrs of recharge until a few days later. I know this dodge wants $190+ for putting the dye into the system. I probably would call ahead to local a/c shop and see how much they want and meanwhile, I would pretend that I didn't know anything... I'll let you guys know what happens later...

Hoppingmad
06-07-2011, 12:34 AM
When my fords got to low, I'd hotwire the compressor so it would suck out of the can and build enough pressure to continue running.

My airconditioner blowing cold air, pressure is up, and even though I have a solid bulkhead behind the seats it doesnt keep up on an 80 deegree day. Thats a fairly small space, any buddy else with this complaint? cure?

bc339
06-07-2011, 01:12 AM
Do you have a thermometer you can place in the vent? It should be about 38-40 degrees F.
I'm constantly in outside temps in the upper 90's, our's keeps me pretty cool with just the front A/C on.

Bruce

eschaton
06-07-2011, 10:55 PM
The dodge stealership put yellow dye into the system yesterday morning. They recharged the a/c to 45psi even though the ambient temperature yesterday was only @ 70 degree. It was inconsistent w/ what the freon can says. Well, I guess perhaps that's why when i only recharged the system to 37 psi and it didn't work while when the tech put in 45psi of freon and it cools down. Anyway, just checked the a/c system's psi and it's now down to 40psi from 45psi yesterday. Somewhere is leaking the freon for sure. I'm going to wait for a few more days to let the dye run through the system before bringing the van back in to find out what is causing the leak. Will keep u guys posted

Dougflas
06-07-2011, 11:20 PM
One thing to take into consideration is that the load on the system will influence the low side psi. If the van's inside ambient temp is high from sitting closed up, the air being sucked over the evaporator will be high and the suction pressure will be high until the van cools down. This is why it is important to have the correct charge in the system in order to troubleshoot. Injecting dye and topping off the system should not cost $190.00. That is a riduculous price.

pdxh2o
06-08-2011, 05:41 AM
I'm a newbie pedaling as fast as i can to catch up...my '05 140" SHC with 75K (watta' score !) has a leaky condenser (looks to be right behind the fan so rock impact unlikely). The original was replaced in '07 @ 44K for the same reason...Europarts SD has 'em for $299 (OEM) but why are they blowing allatime ? Anybody else having this problem ? Also, replace drier / filter of course but anything else too in just 31K ?

Thanks !

bc339
06-08-2011, 05:36 PM
Best guess is the big openings on the Dodge and Freightliner grilles allows debris (rocks) through. Either a screen behind the grille to catch/stop impacts or a MB grille (its got small holes) may help prevent problems.

Bruce

pdxh2o
06-08-2011, 06:15 PM
FYI my research has turned up a huge range of price for drive in R&R service from apparently competent shops...the radiator shop with in stock parts (not OEM) for as low as $500 complete (receiver dryer condenser 134A labor and misc)...the dealer is close to $1K...But I will get the screen or Mgrill too...I can also order the parts from EuroPartsSD and have the R&R done (did me right on the EGR - 10 min kit and other OEM spares for the road too)...