'95 Heater Control Panel. What's The Diff?

[special-K]

I know on the classics when you only get hi-speed fan it's the resistor. On the '95 it just acted wanky and erratic, so I thought it was the switch. Although I did also buy the resistor. I went to replace it on Christmas Eve. Had to give up! How do you guys get at those 6mm screws to get the resistor out?? And I'm sure I'd play hell getting then back in on the install. I had to order a long handle 1/4" drive ratchet that I'm waiting for. It will still be frustrating but at least I might be able to get that in there easier than my handle, and hopefully not have my hand block me from seeing what I'm doing. The new ratchet has a 9" handle

[Boog]

Long handle 1/4" drive ratchet? I'll have to look into one of those.

[b454rat]

I went to the junkyard today and grabbed some stuff, they had I think 5 95s there. And totally forgot to see if any had the HVAC controls......

[Just call me Sean]

I changed the resistor while I was changing the evaporator. Pretty easy with the box on the ground.

[DeadheadNM]

I pulled the glove box out to reach the resistor in my 99.

[special-K]

Hey Boog, I found the one I ordered at Northern Tool. It's made by Milwaukee and looks like a quality tool. I want it for reach, not leverage. Better be careful with that much leverage on a 1/4" drive. Especially in this wonderful world of plastic.

Originally Posted by b454rat

I went to the junkyard today and grabbed some stuff, they had I think 5 95s there. And totally forgot to see if any had the HVAC controls......

No worries. I appreciate the thought, even if it was later . I'm not really interested in a used one. I figure it will be brittle as mine is. I watched a YouTube on replacing the controls. The guy says to be real careful because the tabs can be brittle. He was really careful and every one broke

I really need to hit a junkyard, though. mine is ex-police and they trashed the cluster surround getting equipment out, as well as the cupholder is broken, and so is the glovebox door. The steering wheel looks like someone took a bite out of it at around 12 o'clock. I have a nice upgrade wheel for that. I really want to get my cockpit in order here.

Originally Posted by Just call me Sean

I changed the resistor while I was changing the evaporator. Pretty easy with the box on the ground.

I hate you

Originally Posted by DeadheadNM

I pulled the glove box out to reach the resistor in my 99.

That's where I am. There is about 2" above the heater to get in at it and get the resistor in and out. I watched a video and the guy had to pinch it between his middle and forefinger. I've gotten really used to the benefit of having thumbs . He says watch you don't bend the coils taking it out, then you see him straightening them to assure there was no contact. I don't care about the one coming out. But if they bend and can touch going in, how can you see? I dunno, not looking forward to doing it

[hatzie]

One trick worth noting about fasteners screwed directly into plastics. The vintage computer, game console, and arcade game guys use this trick but it applies here as well.

Plastics get brittle as the plasticizers outgas over time leaving the more brittle base polymers. Heat will accelerate the outgassing.
Slowly turn the screw backwards til you feel the screw threads drop then carefully turn forward so you avoid cutting new threads in the plastic. When you feel the screw get significantly harder to turn you stop right there. You don't run the risk of cracking the brittle plastic bosses and towers that way.
Cutting new threads wallers out the holes as well but cracking the plastics is the more likely problem.

[special-K]

Thanks, good tip. The thing that frustrates me with newer vehicles is the use of tab and clip fasteners. I can deal with nuts, bolts, and screws that I grew up with. I started off working on VWs with magnesium blocks, so learned early on the importance of 'feeling' the resistance. My most common gripe working on new stuff is "Give me a bolt or a screw. I hate clip fasteners!". Those are what broke on my heater control, as well as the guy on You Tube. I have always had issues with that type of fastener. They are all about saving pennies. For someone younger than me who grew up with difficult access where it takes longer to get at the job than the job itself and those gal dern clips, it doesn't seem as frustrating. Just the way it is. But I'm spoiled by the early all metal nut and bolt stuff. One thing I always say is back in the day, designers were given objectives and went to work. They'd come up with a great design, then one would say, "But how will the mechanic get his hand in there to start the threads?", and they'd all agree it was back to the drawing board. But at some point, if one even asked that question at all, they'd all say, "Screw 'em". Another thong I say is
This thing must be designed for children's hands". Yeah, I got spoiled working on the good old stuff. It's a breeze

[Boog]

I used to say the designers took a cheap azz fuse and designed a whole vehicle around it as tightly as possible to save materials. Still true today..

[Just call me Sean]

We have a saying at work. "Eff the next guy."

[special-K]

I can't cop to that. I'm old school and stick to my guns with "Do unto others as you would have then do unto you"

[Just call me Sean]

It's a joke, because we do it all we're the next guy.

[special-K]

I didn't mean to come down on you with that. Just sayin', I couldn't complain if I did it.

We don't know much about each other. I don't know what "at work" is for you. Are you an auto tech... GM tech? I can tell some are and I sure do appreciate having them. You seem familiar, either by profession or personal experience. I'm just learning on these even though I've been running them since '92. Started out as my new trucks that needed nothing. And it takes a long time before they do. I always said about my '92 K3500 I ordered, since I had been building classic GM trucks for decades by then, "I let GMC custom built this one. I just gave them a list".

Still waiting for that long handle 1/4" drive, Jan/4. I'm hoping that will be the ticket to my frustration.

[Just call me Sean]

I fix houses through the HUD program. There are things I do because it makes things easier for the next guy which often is me. For instance, after removing all the interior walls from the house to rebuild the floors I had to put them back. I changed the layout a bit to make better use of the space. I was going to keep the bathroom relatively the same with the toilet on the left wall but there was a floor joist in the way so I put the toilet on the right wall which required framing the door opposite.

I do my own repairs so I make it a point to know my cars. Three are practically the same and I know them pretty well. I'm still figuring out the '99 so it's giving me trouble right now.

[special-K]

You seem to run along a similar path as me. I'm a carpenter who does most anything 'house'. Never worked as a mechanic, but always worked on my own stuff. I have helped friends by fixing their vehicles and homes. I was the VW guy in HS and fixed my friends' and even put some fixed some up to sell other students. I was self-employed since '82 till Oct '20 when I took a job with a historic preservation contractor. Not going well at all at this point, and I don't expect that to continue for long. He's everything I don't want to be. He doesn't believe in enjoying the work, either, and that's the reason I do this type of work.

[special-K]

I've been getting through the winter with no heater fan. Actually, I lost fan function the tail end of last winter. I don't usually wear a jacket when driving, but wearing one makes it warm enough for me. I do have heat, just nothing pushing it. In the evening I shut the doors on a custom-cut tarp for across the windshield, to eliminate the need for the defroster. Works like a champ! My only worry has been driving in snow or freezing precipitation, but I've dodged that bullet so far.

I really do want to fix this issue, though. I found this video and am going to go this route. I've been hung up on paying $200 for an adaptor harness and the other option, change out the plugs as Sean has suggested. I'll just create a rats nest!

Time to hit the junk yard to clip out a 96-00 heater control w/a length of wiring. if the clips all break like mine did, I'll buy an aftermarket unit. They're cheap

1995 Chevy OBS A/C wiring conversion harness -...

[Boog]

Well I put off doing anything with the control panel on our 03 Tahoe for a couple years and recently fixed it. I reasoned that anything I found in the scrap yard would likely be as old and as worn as the one in the truck so I gave in and bought a new one from O'Reillys. Dorman I think and was about $230.
I hated to especially since this is just an extra vehicle I rarely drive but it needs heat. She works again. Yay.

[special-K]

I expect a control panel from the junk yard to be brittle, too. I'm crossing my fingers hoping I'm wrong. Might find a low mileage garaged cream puff that got totalled or something like that. If brittle, I'll just cut the harness parts out and buy an aftermarket. They are on Ebay for $60-ish with a 2 year warranty. I found some used ones there, clip mended, etc. Doesn't look promising for unbroken unit

[Boog]

Hey I just remembered something. The instructions with my new control panel said all functions of the panel may not operate right off the bat as the computer will have to relearn the new switch and it will take a few minutes while it cycles through. I may have had to turn the ignition switch on and off too.
So if your replacement one doesn't fully function right away give it a few minutes before you throw a hammer into it.

[special-K]

Thanks for the tip. I did replace the fan switch twice with new. Both times I had full function right off the bat. Then only in some positions, maybe only high, then nothing. That's why I'm replacing the module behind the glovebox. I'm only buying a new control panel because of broken clips. I thought the first switch was junk. Now I'm thinking I'll have two or three spares. I'm not sure if I tossed the original or not.

[special-K]

I did get to the junk yard last Saturday. The first '96-ups I found all had the harness ends cut out with the control panel left laying. I was thinking this is a hot item and someone comes through and gets them all. But finally I did find one, control panel removed yet, still had harness intact. I had to do a double take and double check I had a Vortec truck. I also got a blue cluster surround and cupholder to go back in with. Now I need to do the replacement.

I think I'm going to replace the module first and see if things work properly. I've put two switches in, the reason I got into this panel replacement saga, and both stopped functioning in short order. I saw a truck in the junkyard that made me feel stupid. It looked like the panel had been replaced and of course the clips snapped off. They had simply screwed the panel back in... DUH! That never occurred to me. Why not? Once in place (and held there) with the surround installed you can't tell. This person just ran a screw in which slip the plastic on the panel, but it held it in. If mine still does it's job I'm going to hold off on the harness conversion. When I do the screw I'll do it right and drill a hole first so the plastic doesn't crack. If all this works out this way, like I said, I feel stupid. I could have had the fan blowing all this time. Not looking forward to replacing that module, though. Looks tedious.

[special-K]

I was looking at heater control panels on Ebay. I found N.O.S. '95s buy for no less than about $350. There are the '96-ups, too, but those are about $200. Then I see the one seller who has an N.O.S. panel also has a reconditioning service for $100. I send mine and it comes back with good slips, new lighting, and anything else it needed. I think I'll do this instead of the screw. Not sure how he goes about the clip fix. I'm going to call first.

https://www.ebay.com/itm/26491081416...pid=4051916254

[special-K]

Changed my mind again! I was going to send my unit to be reconditioned, but after all this time I forgot the main reason for needing to replace it. It's not just the side mount clips that broke, the headlight switch clips are what have me screwed up. I should talk to the guy to confirm, but I'm pretty sure mine is too messed up.

I went to the junkyard hoping a '95 unit was still there that I saw a couple weeks ago. Well, it was but I decided not to take it. First of all, it's got the rear defroster that I don't want. But also, it has other damage maybe worse than mine. I saw so many I got them confused. What I did find was a later panel in a pickup with all good tabs, so I clipped the harness and I guess I'll see about doing the conversion harness

[special-K]

Ooooooo-K. Finally... Yes, finally. I now have this repair completed. No, I'm not lying.

I also have the multi-function switch replaced now. That was such a huge annoyance. I knew I'd be thrilled once that issue was over. That didn't go too bad, and on the passenger seat was the box full of parts I need to install, including the '96-up control panel and harness end. It was time to finally deal with that. My friend who is beyond just a mechanic said screw making that harness and did the pull out/push in pins to switch to the 96-up plugs, as was suggested here. Got it back together, hit the fan, and the blower tried to run but died. breathed it's last breath. so, now it's blower motor time. No biggie

[hatzie]

Good to know it's possible to swap the 95 terminals into the 96 connector and use the 96 up controls. That'll help someone else eventually.