Finally got another 5.0

[Bladez5_0]

Finally got another 5.0. HVAC ducting questions.

Well I decided that since I never really had time/opportunity to off road my jeep like she needed I'd have to let her go. A member of the sportsbikes.ws was trying to sell his Mustang 5.0 and I offered to trade. Well I just got home in this. She needs a little love but she'll be turning heads in no time at all. I've since reinstalled the windshield wipers. She's got the black cloth interior (needs a good vacuuming), short throw shifter (of unknown brand (have 2 upper lever for the base)), Mac 1 5/8 shorty unequal length headers, a flowmaster catback w/2 chambers(unknown series), a new centerforce dual friction clutch (pedal is stiff as hell), and underdrive pulleys. I'm probably going to have to replace the A/C compressor since the clutch doesn't engage and it's spinning off true. The blower inside works but only blows to the floor. It seems like the flappers inside the dash aren't working properly since I don't think there is any ducting that could have come loose. Anyone got any ideas as to why the clutch is so stiff (my 89 with a SPEC stage 3 was way softer than this) and what could be up with the air?
View attachment 471495
View attachment 471496

 

[Jaswir]

for the a/c check a small vacumm line coming out of the vacum tree just above the brake booster... mine broke off there and blowed like urs... and it says a/c on the vacumm tree!

 

[Bladez5_0]

Found the vac line you're talking about Jaswir. Wasn't broken at the vac tree. But it was broken at the other end. I'm planning to get a new vac line to replace it tomorrow.

 

[Bladez5_0]

Well replaced the vac line and still no joy. I started checking the vac operated assemblies in the dash and found what I think is the problem. The silver tab in the middle of the picture(not the canister) operates the flapper for directing air to the upper/lower ducting. Only problem is that I can't reach it well enough to check it. I really don't want to pull the dash apart because it's such a pain.
View attachment 470917

My main concern is whether or not this is the actuator for the flapper or not. If so is there a way to get to it without pulling the dash? The picture was taken from the driverside floorboard looking up. The actuator is behind the (~10" or so)HVAC controls on the left side.

 

[stangbear427]

Not sure. While you're taking pictures though, if you snap one of the shifter we can tell you what you have. Also, I've blown up several Centerforce DF's, they were always stiff as hell before they went. Just something to think about.

 

[iwashmycar]

you may just need a new clutch cable...when i bought my car it was really difficult to push in, and since the guy i bought it off of just thought it was a hard clutch (KC)...it actually started breaking through the firewall....

basically the cable was just binding inside...got a new cable quadrant and adjuster and its all good now

 

[1991vert]

use a pen or pencil to hit the tab? or unfold a paperclip and push it with that. just a thought. dont force anything though to break the tab

 

[RaceDvr50]

There are I think three of these bladders in the system, one controls the air to the floor, one to the defrost, etc. I believe you should be able to access one of these easily if you flip out the glove box. You can pull off the line and see if you are pulling a vacuum there. I have like three whole units in my attic so if you have specific location questions I could look at one tonight.

 

[Bladez5_0]

When the HVAC control it taken too A/C(norm and max) I get a vacuum at the yellow line on the canister in the picture. That tab won't move with a pencil or paperclip due to the angle. I guess the dash comes off this evening.

 

[Bladez5_0]

Okay got the dash off. Gonna set the ground rules. The flapper that sends the supply to either the upper ducting or lower ducting opens(upper ducting) when no vacuum is applied. The defroster/dash flapper supplies the defroster when no vacuum is supplied. The recirc(max A/C) flapper fails to shut with no vacuum. Okay now here's what I've got. Photo is for reference.
View attachment 470808
Yellow vac line(def/dash flapper) gets vacuum when on A/C. It should get vac on A/C, vent, and mix.
White vac line(recirc flapper) gets vacuum(opens) on vent. It should get vac on Max A/C.
Upper/lower ducting flapper(red/blue vac lines) is closed(sends to floor) on vent, open on AC(sends to dash), 1/2 open on floor(sends to floor and dash), open on mix(sends to dash). It should be open on vent, open on A/C, shut on floor, and 1/2 open on mix.
The vacuum is controlled by a sliding plate with a rubber plate that has a pattern on it inside the HVAC switch. The blower and A/C compressor get all the correct signals. The compressor doesn't work because the clutch has gone out on it.
It seems that:
A. I have the wrong switch comletely.
B. My vacuum lines are all jacked up.(not sure how that could happen though and still reach everything.)
C. God hates me.
Anyone got an idea for me?

 

[Roland69]

You should think about a heater core since your in there already.

 

[stangbear427]

A. You have the right switch.
B. Something is wrong, but I have no idea what. Sorry.
C. God doesn't hate you, but Allah does. I wouldn't lose any sleep over it.

 

[Bladez5_0]

Well I took the switch apart, cleaned all the vacuum holes(could see light through all of them already but figured why not), and reinstalled the switch. Everything works now. Not sure what exactly it was but it's better now. Thanks for the help and ideas everyone.

 

[RaceDvr50]

I almost suggested that but I left town for the weekend and was gonna take a look at one of the units in my attic before I opened my mouth. Glad you got it going.