A/C in Bi-Level?

When I select bi-level ventilation mode, the a/c compressor cycles as if I've selected a/c. I think the a/c is operating in the straight ventilation mode also (air flow out of the dash vents only). When ventilation mode selected to floor outlets for heat, no a/c cycling which is what I'd expect in the other two ventilation modes. Any suggestions for troubleshooting are welcome. TIA

Hmmm, I bet the ac is on in all positions except for "off".

Of course, my experience is only with the '97. Even though the shop electrical diagrams indicate a set of contacts to interrupt the ac clutch, the rotary switch didn't get manufactured that way. ... and it was never corrected in the replacement parts stream. I've never opened up a switch to see if it could be corrected.

Just good ole Ford stuff ....

Hmmm, I bet the ac is on in all positions except for "off".
Well, I'm confident the a/c clutch is not engaging while in the floor only, or dash vent only modes. Would you know if the Chiltons manual has accurate electrical schematics for the Escorts?

.....the a/c clutch is not engaging while in the floor only, or dash vent only modes. Would you know if the Chiltons manual has accurate electrical schematics for the Escorts?

Then the '99's controller must be different from my '97's ... and this is expected.

I find the Haynes and Chiltons repair manuals great for all but the electrical concerns. A typical repair manual will cover several model years. My Ford electrical manual for the '97 is just for the '97 ... no other years ... and its probably 300 pages (because of the page numbering system, I can only guess ... or count... the total number of pages) of detailed stuff. The Haynes or Chiltons repair manuals just can't include this huge amount of wiring detail.

I'm sorry to be the one to bring this up, but the 97 and later 'scort is designed to operate the AC in all modes except straight ventilation air flow out the top vents or heated air out of the floor outlet. The AC isn't supposed to come on if the outside temperature is less than 49 degrees, but mine operates all the way down to 39 degrees. All bilevel and defroster modes have the clutch going on the compressor. It's like Ford saying to us that we don't have enough sense to turn the AC on once a week to keep the seal on the compressor lubricated. Ford's stated reasoning behind this according to the manual is to keep humidity levels low in the passenger compartment to prevent fogging. My question is this: Can a switch be wired to the clutch on the compressor to prevent the AC coming on? Will it hurt anything to do it like that? I don't like getting the lower gas mileage. I would lilke to operate the bi-level rather than the top or bottom because it is more comfortable. It would be easy to put a switch on the clutch of the compressor, but I'm afraid it will mess up the Power Control Module or the Constant Control Relay Module. Any thoughts about this? I had a 94 that had the actual AC button on the dash which would only operate the AC when it was on. My 97 isn't like that. It's hard wired into the control switch like 12Ounce says.

Ford's stated reasoning behind this according to the manual ........... My question is this: Can a switch be wired to the clutch on the compressor to prevent the AC coming on?

What manual are you referring too? The shop manual I don't have. If the glove box manual, do you know what section it is in.

My experience (unless I've been smoking something real good!) on two '97 Tracers, two different trim levels, is this:

The ac engages wherever the rotary selector switch is placed ... except for the "off" position. We were pulling the ac fuse during the coldest months (Georgia) just to get away from that uncomfortable blast of cold air on start-ups. I bought and installed a new replacement switch to have the exact same response as with the old switch.
I then got out my "1997 ESCORT TRACER - ELECTRICAL AND VACUUM TROUBLE SHOOTING MANUAL" (printed Mar 1996) and found the contact that someone, early on, expected to be in place. Page 54-1. On the drawing the rotary contacts are shown to perform just like I experience, EXCEPT that there is an internal "ac on-off switch" in series (that I can't locate, ...was it to be a push-pull switch? ... who knows!). There is also a internal (to the rotary switch) "ac on" lamp ... don't have that either. If I get some time, I'll try to scan this page and post it.

By the way, if the switch existed, it would interrupt conductor path #706, which is the O/GN wire going to the ac low pressure switch. I don't see why you couldn't add one here if you wished.

my 1999 lx is the same way. can,t use vent without a/c kicking in. it,s prematurely killing the a/c system.

I wonder what the deal is? The a/c didn't always act like this. I can come up with ways to defeat the a/c, but I want it for de-fogging. Couldn't I tap into the a/c clucth ckt. with a simple switch?

The manual I am referring to is the factory service manual for 97 Escorts. If the outside temp is 49 degrees or more the compressor comes on in all modes except top only or floor only.

I've got the electrical-vacuum troubleshooting manual and it does show (like you said) an AC switch with an on indicator. I don't have this on mine either. My 94 had it though. A little blue light on the dash would come on and the switch was a push-touch type. I see this non-existent switch in circuit 706 between the control assembly and the low-pressure switch. After that it goes to the PCM and CCRM and then on to the AC clutch.

I'm going to put a toggle switch between the control and the low pressure switch. Anyway, like you say, that's where the nonexistent switch is shown in the troubleshooting manual. Should be okay with the PCM and CCRM since they are further downstream.

On page 194-4 they show the testing procedure for the non-esxistent AC switch. It says to connect a test lamp to the terminals of circuit 724 BL/Y and 706 O/GN. If the switch is on the lamp should light up. If I can find these two circuits, this is where I am putting a toggle switch. Yeah, that's the strangest thing that they didn't put that switch in the system where it's shown. Thanks for the help 120unce.
Dave

I had missed reading that testing procedure ... that makes it even "funnier"!

I wonder if the switch out of a "'94" would connect up and provide the switching and the light????

my 1999 lx is the same way. can,t use vent without a/c kicking in. it,s prematurely killing the a/c system. i checked it again. temp is about 42 degree,s here now. in the floor position the a/c does not kick-in. but in bi position a/c kicked-in. piping under hood was cold with warm engine in bi position. in floor position piping was warm.so it is possible to use the heater without the a/c kicking-in.only fresh air to inside of car should be floor position with temp on blue sdie.

Probably could put in a switch and light from a 94. The panel is easy enough to take out. Just probe those 4 holes in the assmbly and disconnect the control cable by the accerator pedal. Cut the right size hole in it and hook it up.

I couldn't find the BL/Y wire or terminal to hook one end of the switch on. I'm just going to put a toggle in between the O/GN wire going to the low pressure swtich. Basically no different than the low pressure switch cutting off the current to the compressor clutch. So much for Ford having a better idea. Better than what? All the best. Dave

I've got the electrical-vacuum troubleshooting manual and it does show (like you said) an AC switch with an on indicator. I don't have this on mine either. My 94 had it though. A little blue light on the dash would come on and the switch was a push-touch type. Dave

I have a '95 and a '96, both with the same switch/light combo as the '94. I guess '97 was perceived as the year of the idiot by Ford with the automatic instead of manual operation.