98' Ltd's Auto Air Conditioning goes crazy/Rear wiper does not work

[05YLT]

Hello,

I have a 98' 4.0 SOHC Limited. My A/C and my rear wiper has been giving me serious problems for over a year now and nobody has been able to fix it. Who knows what to do?

Here is the situation: My Explorer has the Auto Air Conditioning System, it used to work fine. I just had to adjust the temperature and the system would do the rest. This was especially convenient on long road trips.

However, a bit more than a year ago the trouble started: The system started to heat like crazy, even when I switched it to max. A/C. Whenever I accelerated, the system would ventilate less and then again start ventilating like crazy when I stoped to accelerate. Sometimes a lot of steam comes out of the system, blocking the windshield when I accelerate.

First, I got the gas checked and filled up which did not help.
Then I brought it to my local Ford Dealership. They couldn't fix the problem but they blocked the heater so that the A/C would cool at least. I have been driving like this for a year now and it is no fun on long trips. A few weeks ago, my car got a new engine built in by a different mechanic and so I asked them to fix the A/C and the rear wiper (which stopped operating a while ago) at the same time.

They built in the new engine, reconnected the heater, tried a new heater tab but the problem would still consist and so they gave up and refused to try more. Same thing with the rear wiper: They tested the motor (which is ok), tried a few more things and gave up, too.

Has anybody an idea or suffered from the same problem(s)? Any helpfull comments or advises would be highly apreciated.

 

[TheJackal]

Hmm, it's an interesting problem, and I had a similar problem with an 89 Crown Victoria that I had. I suspected the issue was a vacuum leak but never got around to fixing it. The system is supposed to close the valve to the heater core in the Max A/C position. From what it sounds like the defrost vent is opening and closing sporadically and the valve on the heater core isn't closing, all of which I believe are vacuum controlled. I could be wrong but it's worth listening for any unusual hissing noises behind the dash, or any loose hoses not hooked up to anything.

And yes, when I had this problem, the Ford dealer was no help at all. They suggested replacing the fan clutch
Oh and when you're used to looking at LHD Explorers, that picture is kinda freaky.

 

[TedJ]

I've never worked with the newer explorers but in general if it has auto climate control, there has to be some kind of actuators and solenoid valves that let you pressing buttons translate into controlling vacuum actuators and blend doors.

However if the conditions change with accel, I would go with a vacuum related problem. The electronics may be telling it one thing, but since unlike in a manual control vehicle, the blend doors may be vacuum controlled as well, so no matter what the system is trying the vacuum failure will cause everything to go into the default position, which would seem to be full flow through the heater core and defrost.

-Ted

Look for a vacuum leak, there's prolly a lot of lines in there. Applying vacuum with a hand pump may let you more easily find the leak as you don't have the engine noise drowning out the sound of the leak.

 

[05YLT]

I was able to fix the A/C problem by replacing the door blend under the glove department. Those links were really helpfull:
http://www.blenddoorfix.netfirms.com/
http://www.ford-trucks.com/user_gallery/displayimage.php?photoid=56716&width=0

 

[05YLT]

Has anybody an idea about what to do with the rear wiper? Ich have checked all fuses, I tried a new wiper motor and a new rear wiper switch but it still does not work.

 

[andy123]

The mechanics at the dealership wanted to replace my wiper motor, so I had another local mechanic look at it. The arm on the wiper motor was bent in a bit creating too much resistance for the wiper motor to work (wouldn't come out of starting point). After bending the wiper arm to give proper clearance it has worked fine. Not sure of your problem is this or something on the lines of electrical.

 

[cjones101812]

Has anybody an idea about what to do with the rear wiper? Ich have checked all fuses, I tried a new wiper motor and a new rear wiper switch but it still does not work.

are you getting power at the wiper motor between BK/LB and W/O??

if not, do you have power at the relays?? if so, jump the LG wire at the Rear Wiper Up Relay to ground. does the wiper move?? jump the T wire at the Rear Wiper Down Relay to ground. does the wiper move?? if yes to both then check the liftgate Ajar switches and the Liftgate Wiper Disable Switch (located in liftgate wire colors W/P and Bk).