Discussion in 'A/C & Heater systems - HVAC' started by Turdle, August 9, 2007.
You'll need to look for answers in the 3rd gen sub forum. This thread applies to 1995-2001 only.
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hey i saw this post and was wondering what my problem is i have a 1998 ford explorer (eddie baur edition) and the ac blows through the normal vents when its on but when i turn the ac off it constantly blows through the dash defrost vents?
Read through the first few posts, check everything and you'll find it!
Hi so glad I found this thread..
.I had dual problems with removing and repairing the cowl around the radio and then we had the battery replaced.
So now i get the defrost a/c problem
But if i turn it to PANEL
Then blower to first setting
Then turn panel to AC
The ac blows properly and I can turn blower all the way up
Seems like a leak not a fail.
If you were me wpuld you check behind the ac controls
Or the battery area (battery was in and out a few times occurs to me it could weaken the hose)
Love my expedition. Want to keep it forever!
Is this behind the AC controls in the dash? Gotta take out radio bezel and then pull ac controller?
H ( heat) V (vent) AC ( air conditioning)
Yes, on the back of the HVAC control. However, you need to repair your gray line, as it is leaking vacuum which prevents the system from working properly.
I know I'm reviving a dead thread, but I'm new to the forum. This thread has been hugely helpful to my understanding! I have a new-to-me 2001 Sport Trac 4WD with a 4.0 SOHC. It has the same issue with defrost-only HVAC as many others. I have found 3 (at least, up to this point) disconnected vacuum lines hanging loose in the engine compartment.
#1 - Black line coming from the firewall. A rubber connector is on the hose around 2 feet past the firewall. Where does this connect?
#2 - A White/Gray line coming from the firewall. A rubber connector is on the hose just a little longer than the black line. I understand this is a supply line, but from what?
#3 - A Red line coming from the EGR system. This one wraps around the back of the intake and is laying disconnected along the top of the engine. Some genius put a screw in it to plug it, rather than fix the issue.
*Note: I have found an open vacuum hose connection on a cylinder sitting below the alternator. The body looks like a smaller version of the vent door actuators inside the dash. What line connects here and what does it do?
**Also, I found a black line running along the top of the frame rail front to back that goes to something near the brakes. I assume the other end goes to the vacuum reservoir, but I'm going to check that out soon.
Also, what are the two lines from the vacuum reservoir connected to? I guess a hand-holding walkthrough of the vehicle's outside vacuum hose layout would be great. The engine was replaced before I got it, and I suspect the vacuum lines were reconnected shoddy.
#1 connects to a line from the reservoir
#2 should be grey and runs to the vacuum bypass valve in the heater core supply hose
#3 red line goes to the fuel pressure regulator. Green to egr vacuum solenoid
The black lines running along the fenders-engine front to rear are the vacuum source and reservoir lines. there will be 2 back lines attached to the reservoir.
Thanks so much, Turdle. I assume by "fuel pressure regulator," you are talking about the small canister sitting below the alternator? Or is it something else?
Well, I just jacked up the truck and found that the black line running on the frame rail is actually power. The vacuum reservoir has been removed, so there is no supply line. So, now I wonder where the source of the black supply line is in the engine? Until I get another reservoir, I can patch into that, maybe, and get suction from the right source.
By the way, I found the vacuum supply line and patched the gray into that. No issues. But, I found what looks like the FPR on the back of the fuel rail on the passenger side, but I can't find a vacuum port. The only thing I see is the screw-on cap, but that is the pressure relief valve, right? What am I missing?
I think that is the fuel pressure test port. There should be a "pressure damper" with obvious diaphragm shape on the fuel rail also.
Thanks. I'll check for that. Hooked up the red line to the black line, and at least I have A/C right now. But I still need to route the black line back to its source. Anyone know where that hookup is (before the vacuum reservoir)?
I must have a leak in the defrost vent ? because my explorer blows a/c thru the vents but the wind shield get foggy . I checked the vacuum lines before . but my globe is next the overflow tank.
Mine decided to start switching back and forth between defrost and max ac when I’m driving. Time to go leak hunting this weekend. It doesn’t help that it’s in the mid 80’s during December here in Florida and I need my ac to work correctly But hey, we have a “cold” front this weekend with highs in the 70’s so it’ll be a little more pleasant to work outside
Oh, shut up. We're hitting below freezing this week, with highs in the low 40's a couple of days. The people up in the real north have snow on the ground now and I don't envy them either. Have fun there in the heat.
I feel for you because my 98 Mountaineer still has the hot MAX AC problem, the blend door I'm sure. I'm happy I've got heat in the mornings and AC when we do hit the 60* mark occasionally. I've got a leaking roof that I haven't tracked down yet. I sealed the sunroof with RTV, and it still drips just as much. I'm tired of getting wet inside the car. I think the rubber sealing edge might have separated from the glass, it's about all that's left for water to get in and drip from the front corners of the sunroof opening.
Hey, I’m just hoping that the heat will drive some of the snowbirds and tourists away, so traffic isn’t as bad I always wanted a sunroof, but leaks like yours lessen that desire. Good luck sealing that leak, I hope I can find the issue soon as we’ll be back in the 90’s come spring
I love the Fall and Spring, temps between too hot and too cold, 50-70 is my favorite range.