Intermittent AC 2006 / It's hot in Portland Or

PortlandSprinterConnection

enthusiastic t1n packrat
Hey guys! I finally found a 2006 140 sprinter, bought it last week and am working out the bugs.

Asking for ideas on where to start troubleshooting AC. Upon cold start up I can't get the AC to engage. I can drive it for an hour and it won't blow cold, and the refrigerant lines are neither hot nor cold. The compressor clutch won't engage and the electric fan will not turn on.

So far if I park for about 10 minutes with the engine off and start again the AC will kick on. Electric fan turns on, clutch is engaged, and coolant lines are hot and cold. Only tried this a few times, but it's holding true.

Off the top of my head in thinking it's an issue with the climate controls. Sometimes I can't get the heater to engage after turning knob into the red, but if I try a several times eventually it will, then it will behave normally.

Any thoughts appreciated, thx!
 
Last edited:

Midwestdrifter

Engineer In Residence
Search for ATC cracked solder relay. There is a common issue with the clutch control relay which is underneath the temp control knob. The solder on the relay contacts cracks resulting in intermittent clutch operation. A reflow fixes it.
 

PortlandSprinterConnection

enthusiastic t1n packrat
Search for ATC cracked solder relay. There is a common issue with the clutch control relay which is underneath the temp control knob. The solder on the relay contacts cracks resulting in intermittent clutch operation. A reflow fixes it.
This was exactly the kind of suggestion I was hoping for, I'll pull it off this week and check it out! Thanks a bunch!
 

Aqua Puttana

Poly - Thread Finder
...

So far if I park for about 10 minutes with the engine off and start again the AC will kick on. Electric fan turns on, clutch is engaged, and coolant lines are hot and cold. Only tried this a few times, but it's holding true.
...
Which electric fan? The cabin fan, or the aux electric cooling fan mounted to the radiator cooling stack? If the aux electric cooling fan is coming on that would point to a loss of communication on the CAN circuit.

vic
 

PortlandSprinterConnection

enthusiastic t1n packrat
Which electric fan? The cabin fan, or the aux electric cooling fan mounted to the radiator cooling stack? If the aux electric cooling fan is coming on that would point to a loss of communication on the CAN circuit.

vic
Good Q. the Aux electric cooling fan that sits directly behind the grille. Won't kick on when AC doesn't work, will kick on when AC works, at least that's what I've noticed so far.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Under normal operation, the aux fan on the grille stack is activated by a high engine coolant temp, or a high a/c refrigerant pressure (to reject heat from the system, such as in traffic). If there is a loss of CAN bus communication to the ATC module the fan will activate and keep running whether the a/c is on or mot, such as during engine warmup.

-dave
 

Aqua Puttana

Poly - Thread Finder
That's typical behavior.
Not for my 2004 or 2006.

From all that I have read, the T1N Aux Electric Fan is designed to be enabled by Engine Coolant Temperature over 221F, or A/C compressor high side pressure over 300 psi, or a loss of engine temperature sensor signal, or loss of CAN communication because the fan defaults to run if engine temperature feedback is suspect. There may be some other specific triggers which I have missed.

In my experience it is not normal for the Aux Electric Cooling Fan to enable except under the conditions above. The fan doesn't come on every time I activate the A/C.

The reported A/C only working when the Aux Electric Fan is enabled may be providing a clue as to the improper operation/symptoms. Maybe the A/C high pressure sensor or signal is intermittent?

:cheers: vic
 
Last edited:

PortlandSprinterConnection

enthusiastic t1n packrat
It's possible the AUX fan has come on for other circumstances and I've just not noticed it after the AC was working and wrongly correlated them. I'll update this tread when I finally get some time to take a closer look at stuff. thx y'all.
 

PortlandSprinterConnection

enthusiastic t1n packrat
Search for ATC cracked solder relay. There is a common issue with the clutch control relay which is underneath the temp control knob. The solder on the relay contacts cracks resulting in intermittent clutch operation. A reflow fixes it.
You were correct, the solder was cracked. I reflowed it and hooked it back up, AC kicked right on from cold start. Thanks a bunch.

Here's pic of the solder cracked before hand. Also in the pic is my broken vent selector wheel.

https://photos.app.goo.gl/hiFeRbWnDyLkBucdA

Now my second problem, the vent selector wheel has a part of it that is cracked off, and one of the arms slips out of the track. I thought I had it repaired with Jb weld and some Dremel work but it didn't solve it, popped off after I reinstalled it.

Anyone know where I can get a replacement wheel?
 
I got to tell you Thanks Midwestdrifter. Today I fix the solder that was cracked on my 2006 Sprinter RV. Now my AC is working again. Your 2017 post was exactly the problem. 11 cents of solder and a solder wick 30 minute labor.

Thanks again!!!
 

Poloantony

New member
I got to tell you Thanks Midwestdrifter. Today I fix the solder that was cracked on my 2006 Sprinter RV. Now my AC is working again. Your 2017 post was exactly the problem. 11 cents of solder and a solder wick 30 minute labor.

Thanks again!!!
I am currently having this issue and I think it might be cracked solder as well. Any chance you have a write up on how you fixed this?

thanks!
 

Top Bottom