Compressor surging while running AC + DCFC??

[ctuan13]

TL; DR: AC compressor audibly surging while DCFC, stops when cabin HVAC is turned off. AC outputs cold air.

Hi All,
I'm currently traveling and towing my teardrop trailer cross-country like I have for the past two summers.

Its currently scorching where I am. I just passed through Colorado and I'm now in Utah. Temps around 104°F.

I first noticed at the last DCFC stop that I could hear the compressor spooling up sound and the vibration in the floor, followed by a spool down (all within 1 second) and this continued, the entire time I was charging. Ive never experience this before, but there are no fault indications and the charging proceeded normally if maybe slightly slower than max speed.

At my next stop, where I am now, the temps are the same outside and I noticed the same symptom. I then got the idea to try shutting off the AC in the truck and the surging stopped. AC has been blowing cold the entire time.

Has anyone else experience this? Is this just an extreme heat thing?

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[Shmoe]

TL; DR: AC compressor audibly surging while DCFC, stops when cabin HVAC is turned off. AC outputs cold air.

Hi All,
I'm currently traveling and towing my teardrop trailer cross-country like I have for the past two summers.

Its currently scorching where I am. I just passed through Colorado and I'm now in Utah. Temps around 104°F.

I first noticed at the last DCFC stop that I could hear the compressor spooling up sound and the vibration in the floor, followed by a spool down (all within 1 second) and this continued, the entire time I was charging. Ive never experience this before, but there are no fault indications and the charging proceeded normally if maybe slightly slower than max speed.

At my next stop, where I am now, the temps are the same outside and I noticed the same symptom. I then got the idea to try shutting off the AC in the truck and the surging stopped. AC has been blowing cold the entire time.

Has anyone else experience this? Is this just an extreme heat thing?

Yes, the system is cooling your battery so it avoid damage while dcfc.

Edit: should've finished reading.. i've never heard it spinning up and down like that.

 

[JayF]

Take it to the dealer. Cooling system should be covered under EV warranty. Get a video of what's happening. I've had a similar thing here: https://www.f150lightningforum.com/...irst-several-minutes-of-truck-being-on.37228/ and they identified a sticky valve using a combo of my video and the printout of the resolution from Kevin's (Maine Lightning Owner) thread. If anything it sounds like it'll be easier to replicate on yours than mine.

Good luck!

 

[ctuan13]

Yes, the system is cooling your battery so it avoid damage while dcfc.

Edit: should've finished reading.. i've never heard it spinning up and down like that.

Yeah I was gonna say, I totally get what you're saying, I'm very familiar with how the HVAC system cools the pack, but this compressor short cycling is something I've never heard before...

 

[ctuan13]

Take it to the dealer. Cooling system should be covered under EV warranty. Get a video of what's happening. I've had a similar thing here: https://www.f150lightningforum.com/...irst-several-minutes-of-truck-being-on.37228/ and they identified a sticky valve using a combo of my video and the printout of the resolution from Kevin's (Maine Lightning Owner) thread. If anything it sounds like it'll be easier to replicate on yours than mine.

Good luck!

Interesting, yeah I guess it could be that problem. It stopped doing it once the temperature dropped below 97 so I'll try again in the next few days to get a video.

As for the dealer, I won't be able to realistically until I get to my friends place up in Washington, but once there I'll bring it in! Also gonna hook up my autel bi directional scanner and see if I can observe high and low side pressures when it's exhibiting the short cycling behavior.

Thanks for the info!

 

[RLXXI]

You're not hearing the compressor, what you're hearing is the electric fans ramping up and down. If you could hear the compressor, you likely wouldn't have any cold air blowing.

That's my best guess without actually hearing a sound bite.

 

[RickLightning]

The vehicle is supposed to cool the pack while DC charging, and that surges the fans. You hear similar when you turn on the vehicle with AC on if you stand outside (also with the Mach-E). Turn off the AC and it immediately stops.

 

[ctuan13]

You're not hearing the compressor, what you're hearing is the electric fans ramping up and down. If you could hear the compressor, you likely wouldn't have any cold air blowing.

That's my best guess without actually hearing a sound bite.

See I thought that at first as well, but I could hear the fans blowing steady outside the truck, but I only heard (and felt) this noise inside the truck (because it blocked out the roaring electric fans) and was very clearly an AC compressor short cycling.

And I guess while still blowing cold, it wasn't ice cold.

 

[RLXXI]

Sound clip might help.

 

[RocketGhost]

Cooling system should be covered under EV warranty.

I have seen several reports that it is not.

 

[ctuan13]

Well guys, it seems to be getting worse, compressor continues to short cycle when DC fast charging and battery temps rise significantly higher than normal. But if cabin HVAC is turned off, the compressor runs constantly while DC charging and temps are lower.

Also cabin AC still seems to blow cold when driving at least up to around 100°F.

At this point I just need to make it to my friends place in Washington (currently in Idaho), because I'm towing my camper and can't just abandon my truck at some dealership down here. I haven't even had time to run my own diagnostics or check for a refrigerant leak

 

[TaxmanHog]

Does your 2022 Lightning have the 'Max Tow' option?

 

[ctuan13]

Does your 2022 Lightning have the 'Max Tow' option?

Yes it does. From my understanding and according to the shop manual there are two distinct, divorced refrigerant loops, one for the battery and one for the cab. But what I'm not super clear on is is there one compressor or two?

 

[TaxmanHog]

But what I'm not super clear on is is there one compressor or two?

There are two compressors.

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