Need help getting AC back up to normal.

[DickWells]

I just changed batteries, and after I isolated my old one's and checked them out, I don't have much air volumn through the AC. I remember reading about this condition, in here somewhere, but can't find it in the archives. Of course, I can't remember the routine to go through, to re-set the climate controls. Seem to remember that you were one of the people with this problem, Mark. What did you do to get things back?

Thanks:
DW

[DickWells]

Ok, still have a problem, and still can't remember what the routine was that we used to get the air control working properly. What I didn't realize when I posted this thread, was that the specific issue is with the directional control of the blower. Right now, most of the air is going onto the windshield, and no amount of messing with the controls, batteries, or blower fuze will correct it. We get just about enough cold air on ourselves by opening the left rear window about 4" and the right front, about the same.

BTW, the air coming out of the defrost is right at 40 degrees F.

[conway]

For me the problem was that the low speed on the fan was not working. It turned out to be a problem with the fan switch/reostat located in the footwell of the passenger side of the truck. Replaced it and all is well again.

[DmaxMaverick]

For me the problem was that the low speed on the fan was not working. It turned out to be a problem with the fan switch/reostat located in the footwell of the passenger side of the truck. Replaced it and all is well again.

That's the resistor module. Any time the blower doesn't work on all speeds, it's the most common failure. Quite common. Most all vehicle makes use this type of system, and they all suffer about the same failure rate. It's been that way for a few dozen years.

[DickWells]

It's not the fan speed, at all. The blower works all the way from slow to fast. What's wrong is the same problem that (I think) Mark and a couple of others had, a year or so ago. There's no control of "where" the air is going. It's all on the windshield. It was fine, right up to the point where I put in new batteries. The icons all work; IE, the defrost, face only, face and feet, etc. icons all show as you select them with the switch, but the air delivery doesn't go with them. I remember that when some of you had that same, or similar problem, it was really ironic, because I had it at the same time, and went right out to the Sierra and did the same routine, and got my control back. I think the complaint was that someone had lost air delivery to one side, and Mark responded with the cure.

Problem is, I can't remember what you guys did to re-set the dang thing!

Grasping at straws here, but just maybe the re-set involved a disconnect of certain terminals behind the HVAC control panel????? If so, what connectors/colors do I look for, in the absence of my Helms manuals?

Thanks:
DW

[DmaxMaverick]

You might try a system reset. Disconnect both batt+ cables from the batteries, and ground one of them for 30+ minutes. This should reset all the computers to default.

[DickWells]

Thanks, DMAX, will go out right now, and try it. I know that whatever was suggested, back when the issue surfaced for several others at the same (coincidental) time, actually worked. Got my fingers crossed.;)

[DickWells]

Nope. No such luck. Fact is, it ran the same way as yesterday. For a while; then, started throwing hot air, even though the outside temp was 58, and the controls were set at 66 for both sides. Had to shut off the heating/air, alltogether. Turned it back on after an hour or so, and it had gone back to working the same as yesterday, IE, all the air volumn is still going onto the windshield. Put on over 170 miles today, and can't get back to "normal".

Well, we still have defrost, and heat, just can't tell them where to go.:) Up in Missouri, now, and enjoying the Ozarks. Thanks for trying, anyway. Maybe there's still hope out there somewhere?

[dually2002]

Nope. No such luck. Fact is, it ran the same way as yesterday. For a while; then, started throwing hot air, even though the outside temp was 58, and the controls were set at 66 for both sides. Had to shut off the heating/air, alltogether. Turned it back on after an hour or so, and it had gone back to working the same as yesterday, IE, all the air volumn is still going onto the windshield. Put on over 170 miles today, and can't get back to "normal".

Well, we still have defrost, and heat, just can't tell them where to go.:) Up in Missouri, now, and enjoying the Ozarks. Thanks for trying, anyway. Maybe there's still hope out there somewhere?

I think JK posted something about this problem but can't remember the particulars.

[DickWells]

I think you're right, but I've been through the archives, and can't find it anywhere. Probably looking in the wrong place, but I've exhuasted all my own ideas. It might have been JK, not Mark R. whom I remember as furnishing the "routine" that I used to restore mine, before, but my memory has just plain failed me, here. Also, could well be that the whole thing is a coincidence, and happened at the same time as my battery change? "Murphy was an optimist"! Indeed.:D
Thanks.

[bobt]

Dick Do a search using"HVAC Issues". Kennedy has a blurb about his trouble and how he fixed it.
Bob

[DickWells]

Thanks, bobt, that's the one! Now, all I need to do is locate the connectors and actuaters. BTW, there were no codes stored. I forgot to mention it, but I had hooked up the Hypertek, first thing, and there was nothing to delete.

The saga continues, but now I do have some real history to fall back on. I felt that it had to be in here somewhere, just couldn't quite put my finger on it.

Thanks again, everyone.

[JohnC]

BTW, there were no codes stored. I forgot to mention it, but I had hooked up the Hypertek, first thing, and there was nothing to delete.
HVAC would be a body code. I doubt the Hypertek would read that.

[DickWells]

Yes, you're probably right. I'll probably wait, now, until I get home, and get into my Helm manuals. We're able to function pretty well, with the AC, heat, and defrost, since we have enough leakage by the various doors to stay fairly comfortable in both heat and cold.

Thanks again.

[DickWells]

Down in PA, last Wednesday. Jean changed the settings while I was driving and it started blowing air on our faces again. How long this will last is a good question, but I'm content to let it be, for now, and enjoy it.
Thanks for listening, folks.:D