[ScottN]

Yesterday I needed to take off quickly into traffic. I had the AC on and it has been working fine. I put it into sports mode and took off. Put a good deal of revs into it. After I lifted off I noticed the AC was blowing just just hot air (about 90 degrees in NC). I hoped it was maybe an overheating problem. Was going to a restaurant so the car sat for over an hour, no luck on restart.

I pulled the fuse marked AC Compressor (R11). Didi not look blown but I don't have a 7.5A one at the moment. Other checks? Should I pull the relay marked AC Comp?

 

[DominusFL]

Does it start working again when car is cold again? Because mine does the SAME thing. On hot days the decision to "go a little harder" has to be balanced with "how warm do I want to feel"?

Rick

P.S. Maybe this is the newest add-on for the Evora rear seat:
12 volt air conditioner by KoolerAire 12v AC cooler for portable cooling

P.S.S. The high end version:
http://www.sportys.com/PilotShop/product/12933

 

[ScottN]

I'll give it a try in a bit. Probably should have asked this question BEFORE I pulled the fuse in the rear fuse box in the far left corner. I think I'll need to buy about ten 7.5A fuses to account for the number of them I'll drop into the black hole between the interior and body work.

 

[DominusFL]

On my car, I'm discovering it is around 95-degrees where the AC starts getting overwhelmed. Then you want to keep the RPMs down. But next time I take it in I will have them check the AC pressure... maybe it's low. At the last local Lotus meet I pointed out to someone that I am not sure I have an actual AC as much as I have an "AC knob".

 

[ScottN]

I put a new 7.5A fuse in and started the car. I don't hear the compressor come on. Only had it on idle in the garage but don't see where that makes a difference. Put the code scanner on for sport and got nothing. The owners manual shows in the fuses:
Rear box:
- R11 7A a.c. Compressor
- Relay AC Comp

Main box
- C28 5A HVAC ignition

Ideas?

 

[Senna's Dad]

This problem has plagued our cars for a long time. When I picked up my 240S in 2008 and drove from San Francisco to LA through the 90 plus degree temperature in the central valley, the only way I kept cool was to put a bag of ice in front of my seat.

 

[ScottN]

From the Owner's manual:

Air Conditioning Switch
The engine must be running for the a.c. to operate. This switch signals the engine ECU with an air conditioning request, and will maintain its status throughout ignition cycles. The ECU determines whether the running conditions allow for compressor activation. Conditions which will inhibit a.c. include:
- near full throttle demand;
- excessive coolant temperature;
- any fault codes set;
- low refrigerant pressure.
When appropriate, the ECU will activate the a.c. by applying a duty cycle to the compressor solenoid valve, thus generating a swash plate angle and initiating refrigerant flow.

I'll admit to the "near full throttle demand" case. I fear a belt but expect it will be very hard to see. No moisture under the car.

 

[Zippy_Slug]

I may be talking out of my butt and don't really know that much about Evoras.. but I've noticed on the Esprit that the A/C will cut out when the pedal is floored to allow full power to the wheels, rather than turning an engaged compressor. Maybe check a switch around the throttle cable to see if anything is stuck closed. I remember in the good old days this was a physical switch. Maybe the ECU takes care of it now a days. Anyway.. maybe someone who knows more specifically would know about this.

 

[DominusFL]

Same thing would happen in my '93 Miata... turning off AC for full throttle is an old trick.

 

[ScottN]

Ah yes, but how do I get it back on? I can pull the relay I guess. Try and stick my head in where the belt is (hopefully is). No funny noises coming from anywhere. I assume the ECU controls it rather than a mechanical device.

 

[TX_ELISE]

If you don't mind me asking, are you hesitant to take it to Flow to have it checked out?

 

[ByJoveByJingle]

I'm pretty sure there is something wrong with any a/c that seems inadequate. I let things go for a long time in my 2010 n/a, assuming it was a TADTS situation. But I had the a/c looked at and they cleaned out the refrigerant lines. After that there was no situation in Dubai heat that the a/c couldn't handle well. My 2014 is the same. Definitely take it in and get it checked. Why suffer?

 

[ScottN]

If you don't mind me asking, are you hesitant to take it to Flow to have it checked out?

No, not hesitant. Flow is 100 miles away and the compressor stopped working when I stepped down hard for a 5 seconds (0-60) when it was working just fine up to then. I was hoping maybe something I can take care of like a fuse, relay or some reset/fail safe for the compressor if the RPMs got too high.

 

[TX_ELISE]

Ok, got it. When I saw Wake Forest, NC I wasn't thinking of the town but of the school that is in Winston.

 

[2011 chrome orange]

My condenser failed last year. There was no warning and the ac just quite. :facepalm (I was told that there was a known batch that was bad- but yours should have been built after that.)
Anyway, a two minute dye check at the dealer and it was confirmed that the condenser was leaking. Since it was replaced, my ac blows very cold air. (knocking on wood... )

Also, from the service manual:

“The engine ECU is programmed to minimise refrigerant flow until an a.c. request is made, thus allowing the compressor to be run at all times in the interests of system lubrication, and the reduction of inactivity damage.

To safeguard the drive system in the event of compressor seizure, an electromagnetic clutch in the pulley hub is used to disengage the drive as signalled by a sensor in the compressor nose. The clutch will also be disengaged by the ECU if a loss of refrigerant is detected by the trinary switch”

Perhaps you are low on refrigerant pressure? :shrug:

 

[ScottN]

Anything is possible. I will poke around more and if no success then make the appointment. Just seems the cause was the hard acceleration as it was running ok until that point, then the compressor went off.

 

[DominusFL]

All these posts convince me to take mine in to be looked at. Thanks guys.

 

[ScottN]

Took the car to the dealer yesterday for this. AC Compressor was not turning on. They tested to make sure the electronics were working correctly and I guess they were. Ordered a new AC Compressor. Drove home in 95 degrees. Reminded me of being a kid as in the 60s/70s as the family cars didn't have AC. Not too bad but prefer the AC.

 

[F1 SML8R]

Make sure they check it's not a cracked or leaking condenser.


Sent from AutoGuide.com Free App

 

[brgelise]

It can happen to any car. Condenser failed and I'll bet low refrigerant was a contributor making it work too hard.