Hi guys. I had a couple questions about the dealer installed A/C system that I have. I have been reading through some of the threads on this, and I mainly wanted to be clear about what system I have. I know that there are various systems that could have been installed such as "economy air" or even a Sears system. The compressor model number on my system is HR980.

Here is a photo of my HVAC controls:


The way my system currently works is that the far left A/C position activates a blower motor that is installed under the passenger side of the dash. When I turn the fan on, it blows through the dash vents. If I switch the position to "Heat", it blows out the floor vents, and it switches to the normal blower motor. The "Defrost" also uses the non-AC blower motor and blows through the defrost vents.

My first question is whether or not this is a common setup? Most of the pictures I have seen of dealer air show a slightly different looking HVAC control setup. I suspect that normal systems might have the option to have heat go through either the dash or floor vents.

This brings me to my second question. I have had an issue for a while where the selector tab does not like to stay in the left "AC" position if I place it there. It seems to want to stay halfway between the "A/C" and "Heat" positions, rather than all the way to the left. This presents a problem because if it is not far enough to the left, then it won't activate the AC or the AC blower motor. I can have the fan switch on, however, if the selector is not far enough to the "A/C" position, it will use the heater blower motor instead. The following link is a video of my HVAC selector, and it shows how it will only move so far to the left. The minute I let go of it, it moves a little bit back towards the middle, which normally has been barely far enough to activate the AC blower:

My third question is when I have A/C selected, the blower only operates at two speeds, low and high. When Heat is selected, the blower motor operates at 3 different speeds. I don't know if this is by design for dealer air or it could be a bad blower resistor on the AC blower?

Lastly a random question that I have had for some time is what happens if I put the Fuel selector in the middle position between "Front" and "Rear"? It will sit in that middle position if I put it there. So will it draw from neither tank or a default tank?

 

The only two dealer-added HVAC systems I recall having seen have a control panel like yours, OR have a separate control panel mounted in the cubby hole below-right of steering column.

Factory-added AC allows for different floor/dash/defrost settings but all that ductwork is vacuum-controlled; yours is cable-operated... which brings me to...

I watched your video... your ducting is cable-controlled... the hot-cold temp selector controls a flapper door located in the heater box under the hood. Look there... passenger side on the firewall right near where the rubber heater hoses connect, you'll see the other end of the cable and the flapper door to which it connects.

The other cable controls floor-dash-defrost, the other end of that cable is accessible by either removing the glove box liner or possibly by just crawling around in the footwell, you should be able to at least see it. There is another flapper door (diverter) in there, it at once time had foam rubber edges which by now have likely turned to dust... but the point is, that cable operates another flapper door... if that flapper door has become obstructed somehow, that would explain your problem with the lever not going all the way to the left.

Unfortunately, it's probably gonna suck mildly badly if you need to take apart the plenum and ductwork stuff; you *might* be able to remove it without removing the dash (the entire dash, not just the top pad) but I don't know... your problem might be easy, maybe there's a pencil or something stuck in there you can retrieve by just separating the halves a bit... but it's still gonna suck.

The gas tank selector... it switches both the tank and the dash gauge... default is to use the rear tank... I wouldn't place the switch in the middle and hope for anything useful or desirable to happen as a result...

I have no idea how many fan speeds are part of the dealer-added A/C.

 

My '82 has dealer A/C installed but it does not use the HVAC panel it has the rotary switches installed in the glove pocket to the right of the column. One **** controls the temperature via cycling switch and the other controls fan speed. Three speeds if I remember right, slow, medium, and fast.




This **** activates a blower motor mounted behind the dash, which one thing I noticed is the moisture created from the evaporator ends up eventually filling the plenum where the squirrel cage spins at and upon cornering you get a buzzing sound as the water comes into contact with the spinning fan wheel. I have cleaned both drains multiple times and they are clean so I have to chalk it up to a poor design. I have thought about drilling a small hole in the bottom of the squirrel cage pleumn and routing a alternative drain to stop this but desided against it for now.


The HVAC panel switch controls the blower motor under the hood just for the heater, this gives you heat and defrost on mine. This one has three speeds as well, slow, medium, and fast. One thing I noticed on this one of mine which I am not sure if its normal or not but if I drive with the fan speed off I get air being forced in through the cowl vent and into the truck through the duct work. Even if I switch the cable operated blend door to Off I still have air coming through the floor vents. Not a big deal to me but it does bug me some as this is why the inside of the truck is always dusty and dirty.

 

Can you post a picture of the switches in the glove pocket? I've never seen that before. I had dealer AC, but most of mine was removed during the engine swap. However, I still have the extra fan under the dash, and some other parts. I have the same HVAC panel as 86-IDI, and have 3 speeds, low and medium come from the blower motor under the hood, and high comes from the fan under the dash.

 

Sure heres the photo you can see the switches to the far left in the photo. The ones here control just the under dash blower and the HVAC switch controls the one under the hood. They are independent of each other on mine.

 

My truck is a diesel, so where you have those far left switches, I have a glow plug indicator light, "Water in Fuel" light and a engine temp warning light. Maybe depending on application, they went with a different setup (if the warning lights need to stay in that area). I also don't have that black trim on the passenger side of the dash.

 

My 85 Bronco has a system like yours.

 

The diesels were different. I seen a '85 F250 and it was laid out different. Didn't have a dealer a/c though so I couldn't speak on how they would have done that.

 

I'm resurrecting this thread, as I have solved the initial problem and now likely created a new problem. The original problem was as simple as the blend door cable not being correctly adjusted. One quick adjustment and the selector now goes into the A/C position, and activates the A/C blower motor.

I now have a new issue however. The other day when I was driving the truck, I had started it up, turned on the A/C (It's like 80 degrees in California), and as soon as I release the parking brake, the A/C blower motor shuts off. After switching the HVAC selector back and forth a couple times, I get the A/C blower motor to turn back on. While I'm driving I experienced the blower motor shut off a few more times when going over rough road.

When the HVAC selector is an any other position, the heater blower motor will continually run just fine. When I put the HVAC selector into the A/C position, I can hear a little "click" indicating that there is some switch integrated into the control. The problem is that I do not know where to start looking in regards to this issue. I am no expert when it comes to electrical stuff.

 

There is a micro switch on the HVAC controls that the bottom lever has to hit to turn on the dealer ac. That switch can move out of adjustment. If the lever cannot goall the way to the left it will do what you describe.

 

I finally got around to fixing this today, the switch was out of adjustment. It was a simple fix.

One other question I have for you guys. Since my A/C blower only operates at 2 speeds, I pulled the A/C blower resistor out to take a look at it, but it looks like maybe it is only designed to operate at 2 speeds. I can't tell as I am not really that savy with electrical stuff.

Here is the front:


And here is the back: