AC Controls

[UKPR1]

So as I'm just about done with chasing down the electrical system on this new-to-me-1969 truck, I can now turn my attention to why the AC system isn't functioning. The easy answer is that at some point, the belts we taken off the compressor. Thanks to the video and documentation of Randy on this forum, I can chase down most of the wiring and I see that everything that is meant to be electrically connected to one another, still has continuity. Before I go through the process of evacuating the system, pressure testing, etc, the last thing that doesn't seem to be cooperating is the actual AC on/off lever switch on the dash. Is there a trick to it? I don't want to use too much force, but the lever doesn't want to move to the left (I believe to the Cool or AC setting) at all. It's stuck solid as if something is physically preventing it from moving left along it's guide. Moves to the right just fine. This is the AC/Heat/Fan control bundle just below the radio. What is the best way to pop this bank of switches out to see what is preventing it from sliding?

Thanks in advance!

Geoff

[sargentrs]

You can see the mounting studs in the first cable connection photo in this tech article. http://www.fordification.com/tech/AC-cables.htm and in this diagram. Royal pain to get to those nuts. You'll probably have to remove the ashtray, glove box liner and maybe even the radio.

[UKPR1]

Thank you so much for pointing me to that tutorial - not sure why anyone would take the time to produce something as random as a cable guide, but I’m sure glad they did! My money is on the heater valve that cable one goes to is perhaps seized solid and preventing the cable from moving. I’ll free the cable at the valve and see if that allows movement.

Thanks Randy!

Geoff

[sargentrs]

not sure why anyone would take the time to produce something as random as a cable guide, but I’m sure glad they did!

Our founder and mentor, Keith Dickson, has given us so much useful information (Thanks, Keith)! His knowledge, resources and attention to detail is unmatched! Good plan on the heater valve.

[UKPR1]

Then kudos to Keith and many thanks to you once more!

Geoff

[sargentrs]

[UKPR1]

Randy,
Just to circle back...I was wrong! The lever working the 1-2 cables are working fine and articulates the heater valve in the engine bay quite well. The one that is stuck, is the BOTTOM lever pictured in it's stuck position - it can't move any further to the left:

IMG_9870-compressed.JPG

which, from the tutorial you sent to me, articulates the 3-4 cables. From the Figure 3 picture in the tutorial, it looks like Cable 3 allows movement to the right beyond the AIR marking on the switch, but it looks as though the 4 cable is being prevented from moving "up" which in essence allows movement to the left of the AIR setting. What's curious though, is that the picture of the switch in the tutorial is also at the AIR setting...is that just a coincidence or (I have to ask...): is the switch even supposed to operate left of the AIR setting (meaning - is the AIR setting the furthest it will go by design?).

Sorry it's taken me a while to get to this point. I just installed the dream beams (which took a week longer than I thought) and I have a thing about opening the doors with a vehicle up on jack stands...

Best Regards,

Geoff

[sargentrs]

Here's my factory A/C rebuild thread. This will give you a starting point for diagnosis. http://www.fordification.com/forum/view ... =8&t=80023 I would start with disconnecting cable #3 on the left side/end of the unit and work the cable lever to make sure the cable is free and moveable. Also check that the damper operates without the cable connected. It just operates a simple damper that closes of the defrost vents or the register vents depending on the lever's position. Then disconnect the lever at the actuator for the thermoswitch. There are two dampers connected together by a linkage rod. You should be able to get to the forward connection from inside the glove box. There's a spring washer that holds the linkage in place. Once the forward linkage rod is disconnected, see if you can work the cable and the individual dampers manually. This will narrow down where the issue is.

[UKPR1]

Thanks, Randy. Will do.

Geoff

[UKPR1]

Randy:

So...in amongst all the side projects with the truck, I finally got back to this issue. Turns out that cable 4 was frozen (seized) somewhere along it's length. Removing it and working it with some witches brew and it's now moving like it should. However...I noticed that cable 3 was broken at the controls (snapped just after the loop). Following it and looking at the lever that it operates (the heat/defrost door I believe on the left-side of the AC unit) and the loop there was disconnected and the lever seemingly locked up. Used some oil on that too, but that doesn't want to seem to budge even a little.

As much as I would love to get the AC running first to see if I need to ultimately drop the unit, am I looking at having to lower and remove the unit in order to see why this door is frozen (and probably why the cable snapped?).

Thanks in advance,

Geoff

[sargentrs]

The defrost baffle is a simple rotate up/down mechanism consisting of a baffle on a rod. The far end of the rod goes through the case and is captured with a press nut and the other end has another press nut installed to keep it from sliding left to right. There's really nothing that can freeze up and keep it from rotating, just a rod through a hole in a plastic case, nothing to rust together. In the middle of that baffle is a slot that lines up with a plastic rib in the case, IIRC, in between the 2 registers. I noticed as I was putting mine back together that there was enough slack in the rod that the baffle could be pushed too far in either direction and, if the slot wasn't lined up with the rib, the baffle would not rotate. It's possible that someone has pushed/pulled that rod and gotten the press nuts moved to slide the baffle out of position and the slot is not lined up with the rib. See if you can push/pull that rod in/out until you can line up the slot with the rib, you should be able to feel it tapping the rib as you rotate the rod and then feel when it clears it. You can also gently pry out one of the registers, they just click in place and then you can see/feel up in there.

[UKPR1]

You're awesome. Thank you so much for the advice. I'll push/pull on the lever as I try to rotate it, tomorrow. Looked at the registers as what was locking up felt/sounded like it was right behind them, but I couldn't figure out how to get them out...now I do, thanks to you.

Best Regards,

Geoff

[sargentrs]

Oops! Backed up and looked at my old pictures and I don't think you can get the registers out the front. They have pins on the sides and the receptacles are set back from the opening. Might also have clips across the receptacles to keep them from falling back into the case.

[UKPR1]

Well that's a bummer - I think that was going to be my go-to for this one. Well - I'll try to get some lateral movement on that rod instead. I tugged on it and there didn't seem to be an abundance of slack, but let me work with it a little.

Thanks, Randy!

Geoff

[UKPR1]

Well...I took a break from my list of mechanical Things To Do, to take another look at why this door fails to rotate. I tried to push and/or pull the lever while rotating it, but with no success. Visual access to the door was an issue until I found that pulling off the flexible ducts allowed me to look directly at the foam padded top of this door. I could then apply pressure to the door via these duct holes while attempting to rotate the lever. Even with significant pressure, the door still would not rotate.

IMG_0036-compressed.JPG

IMG_0035-compressed.JPG

Fells reminiscent of a condition Randy described in his AC restoration wherein the crimping of the rod, unraveled and stopped rotation. Unless anyone can see a fatal flaw in what I'm doing, I think that disconnecting and dropping this unit, is the only option I have left. Other than the "do nothing" option and leaving it the way it is. But that's not why I got this truck. It's about correcting things one at a time. I'm just a little intimidated about disconnecting the valving on the right hand side through the glove box...its covered in mastic insulation and looks to have almost no room to fit my hands in there and work. I think I'll get the truck running and driving first, and then perhaps wait for the cooler weather to drop the AC unit. Again - talk me out of it or tell me what I'm doing wrong...

EDIT: Let me ask a bone head question...is the operation of this lever dependent on the position of the lever operated by its neighboring cable #4???

Thanks as always,

Geoff