2017 F-Series 6.7L A/C Not Cooling

Keith Browning · July 26, 2017

Found 2 of these so far. A/C compressor not working, no DTC's. Remove the air cleaner housing to access connector C1046 and measure the resistance of the compressor clutch coil from that connector, circuits CH401 (VT-WT) and GD131 (BK-GY) and perform a wiggle test concentrating on the take out for the compressor clutch. This will help identify intermittent problems. Then from under the vehicle pull on that wire take out, it will likely pull off. The wires are breaking right where they exit the main loom.

leon · June 1, 2018

Keith I have 2 '17s right now both no cold air both a/c compressor not engaging.

the first one I have a multitude of problems, 1 being the ms CAN is down. I also load tested the wires from c1046 to the compressor clutch, they were good, I attempted to power and ground the clutch and it does not engage with my power probe. I also unplugged all the connectors in the rear of the truck looking for water and corrosion, I did't see anything but for some reason my ms CAN came back and hasn't faultered since. I wired in a fog light bulb into the compressor connector and it will light when I turn on the ac, I am waiting on a coil/clutch for it.

#2 f550 low and high sides are super high, evacuated and got 1lb. 12 oz. and a shit ton of air. recharged at 1, 8. and am monitoring the system for operation, it is very cold at center vent 44 degrees. blower works on all speeds. system seems right. just not sure why I had air in the system. air flow from vents feels normal at all speeds.

Keith Browning · June 1, 2018

First one sounds like you narrowed it down to the clutch coil nicely but like my original post, remove the convolute from the clutch coil harness take out and give both wires a good tug. Just to be sure. I have now had three of these where where one or both of the wires broke right where the take out exits the main harness. I believe there is also an SSM for this too. Maybe plug in a good strong light (not a test light) and load test the clutch coil circuits first while pulling and testing the harness - wiggle test. Sorry to be repetitive.

The second I have seen twice where the high and low side pressures were high. Ended up being the expansion valves were stuck. Evacuating the system on both, pulling a vacuum and then recharging corrected the condition but I did replace the TXV on both trucks. There was no debris in either as well, perfectly clean.

All were 2017's. HTH

8WA Sman · June 2, 2018

6 hours ago, leon said:

#2 f550 low and high sides are super high, evacuated and got 1lb. 12 oz. and a shit ton of air. recharged at 1, 8.

Air = Moisture

Keith Browning · June 2, 2018

Just some reasonable deduction here: Refrigerant spec for the diesel is 1lb 11 oz. so it was properly charged. I find in my shop between three machines that they do not necessarily measure a charge or recovery accurately. Hard to quantify a "shit ton of air" with a recovered full charge on a system that was likely never opened after the vehicle was built.

leon · June 2, 2018

True, on that Keith. I cannot tell you how much air was in the system. I just know that our machine purged air for a long period of time after recovery (much longer than normally experienced). I recharged a bit less than the spec. just to operate the system to see if pressures went high again. The pressures were at 225 high side and 36 low side at 93 degrees with 80% humidity in the shop. the air flow from the center vents was normal and 44 f. I operated it a couple of times with about 30 minutes rest in between. and both times it worked normally. I appreciate the heads up on the wire issue, and yes there is a message or bulletin on that. I will open that wiring convolute up and verify the circuits...the wire ties appear to really be tight on the loom.

leon · June 2, 2018

When I said the pressures were super high, they were at 380 high side and 175 low side this was a couple of minutes after it quit working when I was verifying the concern. These were the pressures in the system without it operating. Then I evacuated and recharged. since then its working normally.

forddieseldoctor · June 3, 2018

7 hours ago, leon said:

When I said the pressures were super high, they were at 380 high side and 175 low side this was a couple of minutes after it quit working when I was verifying the concern. These were the pressures in the system without it operating. Then I evacuated and recharged. since then its working normally.

We had a 17 550 with 20k on it that had the same thing. We evacuated and recharged and it’s working now. The system was not low.

8WA Sman · June 3, 2018

Anybody test these with an identifier?

Is this wiring issue the reason for SSM 46878?

You could also remove the A/C clutch relay to check the circuits and get an amp capture or reading.

leon · June 3, 2018

I did not identify the Freon...our dealer, uhm, well, we don't have one. We need to get one.

forddieseldoctor · June 3, 2018

14 hours ago, 8WA Sman said:

Anybody test these with an identifier?

What’s an indentifier?

Oh wait... I remember seeing one of those once at the Ford training center.

leon · June 7, 2018

"but like my original post, remove the convolute from the clutch coil harness take out and give both wires a good tug. Just to be sure. " (Keith Browning)

I did and I did find the ground circuit broke at one of the zip ties, they were really squeezed tight and I went so far as to go back in the harness as far as I could and cut out the power and ground circuits to my coil, and installed about 7 " good wire performed wiggle test again and all good. You told me twice, I knew you meant business. Thanks for that.