2006 Dodge Sprinter 2500 A/C System Trouble, Diagnostic info posted

misterbond10

New member
My A/C Problems:

The vehicle was purchased used last year with 110,000 miles

The A/C compressor clutch at first would not engage. Hooked up a manifold gauge set, and it read about 30 low side/0 high side

First thing I did was remove and reinstall all the fuses under the seat, no change

Next I cut through the insulation to the compressor clutch wire in the engine bay to see if it was getting 12v. For some reason that is beyond me, this is when the compressor clutch finally started engaging.

The condenser fan will NOT come on unless the A/C transducer on the drier is unplugged. After about 3 seconds of unplugging the transducer aka pressure sensor, the A/C clutch disengages

I vacuumed the system for an hour, it seemed to hold the vacuum after leaving it sit for an hour. I proceeded to recharge the system with 1.9lbs of R134a

During testing with the A/C running, I received a low temp of 58 out of the Left drivers vent, and 70 out of the center vent. Outside temp was about 70 degrees. Max cold, Bi-level vents selected, maximum blower speed.

Manifold gauge readings after the final tank of R134 went in are as follows:
Low Side High Side
-----------------------------------
40 135
38 155
39 165
40 175
40 210

One thing to note is the High Side never gets above 210 no matter how long it sits with the condenser fan NOT running. If I get the condensor fan to run (which means the A/C will NOT be running) it will cool it down to 135 on the high side, same thing happens if I spray water on the condensor while the A/C is running.

Currently the ATC is plugged in but accessable for diagnostics (I removed the trim panels around it)

Yes the cabin filter has been changed

Fluorescent dye was visable around the pressure port connections on the A/C lines, but this could be dyed from the factory?

Any help would be greatly appreciated. Thank you.
 

MercedesGenIn

Mercedes-Benz Resource
Interesting results.
Discounting the possibility of a faulty compressor, I would be looking at the compressor magnetic clutch if I was seeing those results. Especially as you say it all burst into life when you played around with the coil wires. If the clutch was not holding in sufficiently, there would be some slippage - meaning full potential of the compressor would never be reached. It may also be worth checking the air gap on the clutch between the plate and pulley (on the Nippon's a gap of over 0.9mm and it would slip!) so would be worth a quick look here too.

Hope this helps, as in essence everything does seem to be working as it should, bar the obtained pressures.
 
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misterbond10

New member
Interesting results.
Discounting the possibility of a faulty compressor, I would be looking at the compressor magnetic clutch if I was seeing those results. Especially as you say it all burst into life when you played around with the coil wires. If the clutch was not holding in sufficiently, there would be some slippage - meaning full potential of the compressor would never be reached. It may also be worth checking the air gap on the clutch between the plate and pulley (on the Nippon's a gap of over 0.9mm and it would slip!) so would be worth a quick look here too.

Hope this helps, as in essence everything does seem to be working as it should, bar the obtained pressures.
I always assumed a compression clutch would either engage or not at all, was not aware that slippage could be a problem. I have examined it quite a bit while running and have not heard or seen any slippage while it is engaged, but checking the air gap is something I have done before and would be easy to check...

The pressures im getting are normal?
 

MercedesGenIn

Mercedes-Benz Resource
A quick look with a good torch may reveal some heat 'blueing' of the plates if you can peer into the gap, otherwise the only sure way to inspect it is drop the front off. Have a look here it, may give you a few other pointers.
http://www.ryderfleetproducts.com/examining-clutch-failures/t-1229744

Following the route of slippage if you feel its worth pursuing, is anything amiss that may effect the delivery of the correct current to the clutch coil, wiring, connections and of course perhaps a low resistance relay component in the control circuit.

All the best and good luck,
Steve
 
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misterbond10

New member
Great information steve, Thank you!

EDIT: Upon checking the manual just now, I cannot find ANY specifications as to what the air gap should be in my 140" cargo T1N (no aux A/C)
 
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Dougflas

DAD OWNER
Your 0 psi high side reading may be because the hose did not activate the schrader. #0 pis on the low side is within range. The electric fan will not engage if the high side pressires do not get high enough to activate the cut out switch thus this means the water pump fan is keeping the high side pressures down. (Normal). Now if you get 0 high side and the hose does activate the schrader, then my guess is a blockage most likely at the TXV. Sometimes rapping the TXV with the handle of a screwdriver will unstick the metering needle. You also need to give us the ambient temperature taken in front of the grill. Normal AC specs are to have the idle at 1500rmp, doors/windows open, and temp at center duct.

Do a search in the blue bar above. Dennis from Lindenengeering had a post recently explaining the operation of the Ac system and exactly when the electric fan should cut in and out.
 
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misterbond10

New member
Your 0 psi high side reading may be because the hose did not activate the schrader. #0 pis on the low side is within range. The electric fan will not engage if the high side pressires do not get high enough to activate the cut out switch thus this means the water pump fan is keeping the high side pressures down. (Normal). Now if you get 0 high side and the hose does activate the schrader, then my guess is a blockage most likely at the TXV. Sometimes rapping the TXV with the handle of a screwdriver will unstick the metering needle. You also need to give us the ambient temperature taken in front of the grill. Normal AC specs are to have the idle at 1500rmp, doors/windows open, and temp at center duct.

Do a search in the blue bar above. Dennis from Lindenengeering had a post recently explaining the operation of the Ac system and exactly when the electric fan should cut in and out.
Ambient temp in front of the grill was 70-73 degrees. During testing I had a powerful industrial fan blowing into the condenser since the condenser fan would not run.
 

misterbond10

New member
So I checked out the A/C Clutch the other day, measured all around and could not fit anything bigger than a .675mm feeler gauge in there. Take note this van only has 120000 miles


the ambient temp in front of the grill was 70-73 degrees. During testing I had a powerful industrial fan blowing into the condenser since the condenser fan would not run.

How many different things can control the condenser fan? I've thought about repeating the test with restricted airflow to the condenser, to see if I can get the high side to go past 210

Any ideas on where to go from here? I wish you could just mark the pulley and use a timing light mechanism to see if the pulley is slipping while running :rad:
 

lindenengineering

Well-known member
So I checked out the A/C Clutch the other day, measured all around and could not fit anything bigger than a .675mm feeler gauge in there. Take note this van only has 120000 miles


the ambient temp in front of the grill was 70-73 degrees. During testing I had a powerful industrial fan blowing into the condenser since the condenser fan would not run.

How many different things can control the condenser fan? I've thought about repeating the test with restricted airflow to the condenser, to see if I can get the high side to go past 210

Any ideas on where to go from here? I wish you could just mark the pulley and use a timing light mechanism to see if the pulley is slipping while running :rad:
Just a few points.
ASI tech test question#1
A car isn't cabin cooling correctly. What is the first thing to do?
Answer;
Evacuate the system and measure the refrigeration quantity and quality for contamination such as air and rogue elements.

With that stated as a caveat

The refrigerant charge how was it checked as being the correct weight? 1.9 lbs???
If refrigerant was added was it pure R134a?
Have you verified that the system was devoid of air--read very important.
If all that is in order and you haven't been trying to fill it from cans with sealant bought at a parts store with limited delivery/recycling equipment?
If not then do a full cool test.

Remove the 12v wire from the compressor clutch and connect a jumper wire from the battery or good known 12v source.
Run the engine at 2000 r/m with gauges a connected and observe pressure.
As a rule high side is 2.5 times ambient. Measure that temp using an infrared heat gun
Low side should stabilize at about 25/30 psi after a few minutes running.
Run the heat gun over the condenser looking for dead spots or high spots on the matrix .

Depending upon ambient, high side will rise to 325 to 350 then the condenser fan should kick in and the high side should drop to pressures below 225 whereupon it should trip out!
Observe the high side when it stabilizes, determined by ambient calculation of 2.5 times!

With the the heat gun shoot vent temps at the dash board and remove the cabin filter and shoot the temp on the evap matrix & compare!

PS If you use the industrial fan then the condenser fan won't trip in, since you are taking heat away so it is dropping the high side pressure to below threshold trip.
If the clutch is slipping you will see it observing the gauges on full cool test.
Also although a bit difficult on the Sprinter but observe the flow of refrigerant in the sight glass. It should have no foam or bubbles flowing through it as it is in the liquid line.
Dennis

I am forced to mention that this A/C & refrigeration stuff is specialist work and you need training for it to fix and diagnose problems properly. It formed part of a Euro MV apprenticeship, still does, but I did spend 6 months part time in school here in the the US to obtain my EPA certification.
Now if you are not in this business but you want to know more your local vocational tech college will most likely have course on how to repair and fix your cars A/C system ,
How long R134a will be available to the unlicensed public is anyone's' guess but I would enjoy that now as the Eurozone has banned the buying of refrigerant by the public in general.
Dennis
 

misterbond10

New member
Douglas: Thank you, I will call this evening

Lindenengineering: The system was first evacuated for an hour, manifold gauge set attached.

The R134a was purchased in 12oz cans. using a 500g scale, i weighed a full can, then an empty can, then did some math and put in exactly 1.9lbs

I was wondering if a cold can weighed different then a warm one, it does not!

I have NOT used any kind of stop leak nonsense, and i probably never will in this lifetime.

During charging/testing I was running the motor at about 1200rpm

What do you mean by 'Run the heat gun over the condenser looking for dead spots or high spots on the matrix'. And are you asking me to measure the high side temps with infrared gun on the condenser? I do have an infra-therm. Also the manifold gauge set has temperature markings on the high side (pressure/temp are directly related right?)

Now I read a post from you a few weeks ago that said once the high side reached about 210, thats when the condenser fan was supposed to come on. Is it supposed to activate at 210psi or 325-350psi?

You talk about using a heat gun...are you referring to the infrared thermometer? I was confused thinking you were wanting me to shoot hot air at the ATC temp sensor.
With the the heat gun shoot vent temps at the dash board and remove the cabin filter and shoot the temp on the evap matrix & compare!

Good call on the sight glass. My engine bay is beyond nasty, forgot to clean off that glass



THANK YOU ALL SO MUCH. And lindenengineering, you are basically a saint. As far as getting R134a I would be happy to ship you some, not sure if you can order any i've only bought locally, but here in the US (maybe not california) you can purchase no problem. I try my best to be eco-conscientious and recycle whatever I can. Is it called ASI in europe? Here in the states its called ASE (automotive service excellence). Still working on my test books...
 

Dougflas

DAD OWNER
the auxiliary fan is supposed to kick in around 325ish and drop out around 210ish. Dennis meant to aim the thermal thermomoter at the condenser in various areas to determine if there is a blockage. If your high side is below 210, the aux fans will not activate.
 

Dougflas

DAD OWNER
After rereading these posts, I noticed something that does not seem correct. You stated the left vent has a discharge temp of 58* and the center is 70*. This does not seem normal. The evaporator is on the passenger side of the dash. thus, the vent temp on the passenger side has to be colder than the diver's side. The vent temps should get slightly higher out of the center and driver's side. This points to ducting problems in the dash.

If you think the clutch is slipping,watch closely the high side guage for pulsations of the needle. If you want to check operation of the aux fans kicking in, block the condenser with cardboard. The high side will increase and when the high side increases to 325, the fans should turn on. remove the cardboard and they should shut down around 225. Also, make sure your guages are zeroed before you connect them. 1.9 lbs of refrigerant is 1 lb 15 oz so for practical purposes, you need 2 lbs of R134. This charge is not that critical as you have a drier on the fender well that is designed to store refrigerant as well as absorb moisture. You have a TXV system (expansion valve). That is your metering device tha tmeters the refrigerant entering the evap. It is located in the engine area near the low side connection. It is called a "H" valve in the industry.

Dennis mentioned to "shoot" the condenser with a heat gun and measure the condenser with a thermal thermometer. I do not feel your condenser is a problem. If it were, your high side would be high unless there was a blockage in it. You should see a cold spot directly after the blockage.

I am takiing for granted you have the correct amount of regrigerant in the system. 30 psi low side and 210 high side at the ambient you stated is really normal. Recheck your vent temps to see if you misstated the temps. Measure the evaporator line temps directly entering and leaving. They should be close to the same with leaving slightly colder. You could have an intermittent operation of the clutch due to the relay solder connections on the control head. There is a guy on ebay that overhauls them for just under $100.00. (common problem) To check for this, run a small lamp from ground and the clutch lead into the cabin area. When the AC should be on the lamp will be lit.
 
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misterbond10

New member
OK, so I repeated the test today with cardboard blocking the airflow. I got the high side up to around 355, condenser fan DID NOT come on. The fan will still come on if you remove the accumulator/drier pressure sensor. I got about 30 on the low side, ambient temp 65 degrees Farenheit. I also looked on my drier for a sight glass but could not find one! is the sight glass on the condenser?

Does this mean my ATC is bad? What else could cause the condenser fan not to come on?

I again took vent outlet temperatures with the A/C running, and the center vents (which should be coldest?) blew warmer than the left drivers vent. I was able to achieve a low temp of 40 degrees today out of the drivers left upper vent.


Thanks
 
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G

Gordon Smith

Guest
I don't know anything about this A/C diagnosis (or Sprinter mechanicals in general), but I have to say that I love a thread like this one. It's like listening to a group of white-smocked, world-class surgeons in the operating room…speaking a language that I don't understand, doing their best to save the patient. Kudos to you guys.
 

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