Disconnecting air conditioning. (higher mpg)

[tlutz211]

Wires are fine ... And I just barely have to tap it and it starts right back up so I guess I should prob just replace the clutch before it goes completely out?

 

[budwich]

Budwich, you are at least partially correct. This morning I removed the heater control panel and did some checking with a test light. In vent (dash) and floor position the purple wire was NOT hot, in all other positions the wire was hot. I have to assume the purple wire sends a signal to turn on the compressor, by way of my testing. So my apologies to you, sir. However the damn compressor still cycles when in the mix(floor and dash) position.

I think that's how it was designed. There isn't an easy solution to your "mixed" (floor and dash) mode to not have an AC component. I do believe that the switch can be modded just like the other two positions by cutting/breaking the connection point / contact point on the rotary switch.... but I have never seen or done this mod.

NOTE: the rotary switch is a dual gang switch with one gang controlling the heater blower (thru placement of a ground) and the other gang controlling the A/C "driving power" (thru conduction of voltage).

Further note: I do believe your PCM detects that there is power going thru the A/C drive circuit and does some "miracles" to ensure that your engine runs under the change in load that may happen when your A/C cycles.

 

[Karpiel73]

Karpeil73, that is the case with my, and it seems a lot of others. Maybe it not supposed to, but it does.

Thanks

 

[storlied]

Which fuse had to be pulled from under the hood to stop the AC from cycling? And to verify, I do NOT need this for heat?

 

[yavapaires]

Storlied, you can just unplug the two wire connector on the A/C compressor. And no, you will not affect the heat.

 

[SoNic67]

Or you can just use the "VENT" position on the A/C controller instead of demolishing your car...

 

[storlied]

Time to make another killswitch then I guess.

 

[jimwww]

Why I started this thread.

When I got my 96 a couple years ago (ohv) 5spd, I wondered why it was getting pretty good mileage in it for a couple months. Quite a bit more than my 1999 sohv auto that I had before it. (not the 99 I have now). The air conditioning did not work on it when I got it, it got warm that summer and my mechanic looked under the hood and connected the compressor and that gave me air conditioning. It was hot that summer. When the summer was over I stopped using the air conditioning but my mileage did not return. Also when the compressor was connected I could hear the click of it coming on. It was loud. I wondered why it was cycling every five min or so- that is when I figured there was no off switch. I disconnected it and my mileage went back up.

I have a 99 that is getting 425km a tank and wanted to disconnect it and see if it makes a difference. We pay 1.42 cents a liter up here in Canada - 3.8.liters to every one USA gallon. (5.39$ canadian for one usa gallon)

I am going to disconnect it soon and see what happens.

 

[Trolling]

does anybody have a pic of the connector on the compressor and the fuse that you guys take out?

I've never heard the compressor cycle on mine as I've kept the knob on OFF but i still want to see if unplugging the compressor would improve my mpg.

 

[Karpiel73]

Well, if you see the accumulator bottle, the 2 wired switch is in the "curled" hard line. I have no picture.

Went out and took a quick picture. Turdle, is the top picture the line you're referring too?

 

[jimwww]

I just did my tune up today, new wires, new spark plugs and disconnected the a/c which my mechanic agreed w me that on fords the stupid thing 'cycles' using up more gas than you need to in the winter. I will post some pics as well so you all can do it too. My mechanic did suggest that once a month plug it back in for a day ( which I agree)

Let's see how much difference all this makes for the next three tanks of gas. I invite you guys to do the same.

 

[SoNic67]

In Vancover you don't need A/C. You can do your little experiment (or you could leave the A/C on "Vent" like the manual says).
For people that live at lower latitudes (with hotter summers) and don't like to be smelly/sweaty when they walk into their office, the A/C is a necessity that is worth the gas money.

PS: Necessity is a broad term. Some might get by without toilet paper, also. But some don't mind the fact that they have to pay for it.

 

[jimwww]

We get 20-26 weeks of sun here in the summer ( nobody ever talks a out that) and no humidity. I intend to find out if turning off that condenser makes a difference or not. It did on my 96. I used to live in L A and used air everyday. Fyi - on vent I can still hear it cycle so that is why I disconnected it yesterday. I am interested to see if I can recreate the same thing in my 96. If not, that's OK.

I measure my mileage for work and use the exact same gas(Chevron)- so we will see over the next few weeks.

 

[jimwww]

Well it has been three weeks and my mileage went up by 50km per tank so far. Not as good as my 96 - it was better but I do know I need a brake adjustment on the front (my back brakes were done three weeks ago). I invite you to try this modification on your to see if it effects anything.. if you are in a climate where you do not require a/c yet. I would not do this if I lived in LA or AZ or TX.

 

[masospaghetti]

The A/C will run in the MAX, A/C, VENT/FLOOR MIX, DEFROST/FLOOR MIX, and DEFROST.

The A/C will NOT run in the OFF POSITION, VENT ONLY or FLOOR ONLY.

It's been like this on every domestic car that i've owned.

I believe Ford did it, as others have said, to have the compressor run more often that it would otherwise to keep all of the o-rings from drying out.

I would highly recommend against disconnecting components to try and save a buck...if its cool outside, even if you engage the A/C compressor, its only going to cycle on briefly because it doesn't have to work hard to dehumdify the already cool outside air...its not going to save you a significant amount of fuel. IMO, not having air conditioning can be a safety hazard if its humid outside and the windows begin fogging.

 

[jimwww]

I think we have already talked about that subject. I think we do not need to argue about it anymore. Some believe it some don't. On my 96 it ran regardless. Unplugging it stopped it.

 

[Definca]

Another vote to run a simple on off switch from the ac clutch wire to the dash. Has many useful advantages, one being setting to max ac and when you are a couple blocks from home turn off the compressor to warm, drain, and dry off the evaporator. Additionally, when on a hill or emergency passing it is far easier to kill the compressor than switching between blend doors and air arrangements, which continually break in Fords.

 

[lobo411]

Well this is a really old thread, but I found it hilarious and entertaining nonetheless--the way some people believed passionately and sincerely that the a/c comes on all the time. Hahaha!

Someone start a thread on whether the light goes out or stays on when you close the fridge door!

 

[JusTheUsual]

I know vehicles will run ac on windshield positions because of humidity. That's why in winter you use defrost windshield position as little as possible for better gas mileage and better mpg. While off, and vent, ac will not kick on. If your's is kicking on I would bet it's because of something wrong. Mythbusters had a episode on their show saying having ac on will not reduce mpg and hp. I was like wtf! I still argue to this day with some of my idiot friends that even having ac compressor running a belt around it will reduce mpg and hp. Its about 15hp just having to run a belt around the ac compressor. That's why racers don't have ac in their race cars.

 

[koda2000]

Well this is a really old thread, but I found it hilarious and entertaining nonetheless--the way some people believed passionately and sincerely that the a/c comes on all the time. Hahaha!

Someone start a thread on whether the light goes out or stays on when you close the fridge door!

Actually you are mistaken. With the Explorer (and I imagine other Fords) the A/C compressor can run in any setting except VENT and FLOOR. I suggest you try reading your owner's manual.

While it is true the compressor takes HP to run, I'd rather be cool. I once had a friend that constantly turned his A/C on and off. It drove me nuts to ride in his car and besides being annoying for his passengers, it was a complete waste of time.

In my experience running the A/C reduces fuel economy by maybe 1.5-2 MPG. On a 20 gallon tank that comes out to 40 fewer miles per tank. At todays fuel prices that's around $5. Not even the price of a lunch at McD's. If you'd rather sweat - just don't turn the A/C on. As far as the belt spinning the A/C pulley when the compressor isn't engaged, it requires near zero HP to just spin the bearing. Not worth worrying about.