I noticed in pictures on the forum that some C4s have a manual temperature setting (slide ****) for the climate control. I have the Auto-CC in my 93, which I hate. Is there anyway to convert this without many modifications? Is it just a different control panel in the dash? I would like to go this route but would also like to be able to return the original one if need be?

 

Why don't you like it? I have the manual. I was wondering if I should switch to the auto.

 

The thing seems to have a mind of its own, I guess its the control freak in me, but I like the the idea of turning the fan and temp up and down when I want to. I have it in my 05 GTP and that drives me nuts too.

 

You could probably get the right answer from Gordon Killebrew. He charges for the phone session but it might be worth ten bucks to find out and do it correctly. www.gordonkillebrew.com
You could also try www.vette2vette.com for a used one along with free advice from Jason. He should know also as Gordon has been training him in the "art of the C4 and ZR-1".
Let us know as there are many C4 owners out there with squirrely electronic AC controllers.

 

GM pretty much uses the same manual and electronic a/c set up in everything with the only differences being the graphics (and size) on the control panel. The '96 electronic a/c might be an exception if only because the cost of the Processor or Programmer is 6 times that of the other Years. In any event, swapping one for the other can be a challenge, especially beginning and after the '90. That's when they decided that the ECM should control compressor engagement and each system has a somewhat different interface. On none of the Years can you simply swap out the dash panel.

If you want to do this for Year, then I'd get the Shop Manual and find a donor for the system you want. And make sure you get the vacuum harness (from inside the Firewall forward) for whatever you're switching too. You'll have to examine the electrical harness (using the manual schematic as a guide) to determine what wiring you may or may not need. ECM/PCM and the CCM may also need a reflash (later Years).

 

There was another thread about this awhile ago-can't say how long. Try some searching. When I finally get my '89, I figured I'd refit the heater/AC control to manual if it's auto. From studying my '89 FSM, I think the only difference is in the final mechanical connection to the plenum door on the far right side, air blend (air temp) I think. The auto is driven by a stepper motor and the manual is a link from the push-pull cable. The vacuum hoses to the vac motors should be the same since the basic system is the same for both versions. I suspect the manual control unit from my '89 Caprice may work but I won't know for sure until I get the 'vette. Based on what SunCr says above, the donor only route would likely be the best bet for a '93. Good luck.

 

Tony - Congrats - I didn't know you finally bought a Vette!

As far as I know, the vacuum harnesses aren't interchangeable. Manual controls all of the solenoids from the Control Panel and as you turn the ****, ports are covered and uncovered to direct suction towards the appropriate door. Electronic sends an electric signal to a Processor (later Years are serial data) and it handles the switching. That Processor is mounted a long way away (relative to the Control Panel) and needs a longer harness (along with an additional electrical harness).

 

Don't sound like a simple controller change?

 

Thanks, but hold the congrats: I only bought the FSM so far!

I'm assuming by "solenoids" you mean vacuum motors. What I meant in previous post was the control functions, i.e. number of vac lines and where they go, I think (from the FSM) are identical.

By the way, there's a Charcoal '89 in SD that fits my specs beautiful. I had my son check it out and take a bunch of pics. Only problem that kept me from flying out there was the fact that it's leaking oil-probably like a seive. That's not a good sign for a decent engine for several reasons and it's at a dealer to boot. Enjoy the weather!

 

Thanks for all the input! Does'nt seem like anything Id want to tackle.
But your replies are appreciated.

 

Hehe I thought it was just me who didin`t like electronic climate!

My 86 was the 1st car I`ve ever had it on - and I used to wind the windows down in the middle of winter just to force it to bring the hot air on :P

Love the idea of it - and it`s gr8 when u like open a door and get back in and it`s nice and warm - but I think I`m just 1 of those ppl thats just cold all the time and likes hot air blowing on my face the entire journey!

Was gr8 getting up to temperature - but once it reached the temp and cut the heat down , I used to start shivering lol.

I know u can overide it so it blows full heat all the time - but then it was burning hot and a bit too much.

Obviously not just the Vette, cos I`ve now got an MR2 with climate and it`s just the same. In fact I use my Fiero all winter now just cos it`s got manual heat lol.

I know the 93`s r a bit more advanced than my 86 was - but I did find a little trick: although the max setting was 85 and pressing it once more to 90 made it go on full heat all the time - if u turned the car off with the setting at 90 and then started it again, it would actually get much hotter than the 85 setting but still not full heat all the time like if u just pressed it to 90 normally. Don`t ask me why but it just about made it bearable in winter....

Cheers,

Dom

 

Can't you do that with what you have now pretty much the same way by setting the temp at whatever and picking the fan speed yourself rather than pushing the 'auto' button?

In the morning when it's cold, I set my temp to 90, fan to 1 till the engine gets warm, then I push 'auto' which sets the fan to 10. I could pick fan speed too, but 10's ok till it gets warm. When it gets warm enough I turn the temp down to 75. In the summer when the sun is roasting me, I set the temp at as cold as it goes whatever that is, and select 10 for the fan speed. If it gets to cool, I'll select 70 degrees or so and either pick a fan speed or let the climate control decide.

All in all, mine seems to be able to be operated about the same as if it had slider controls and cables to me. jmo

 

If this is true, GM must have been having a bad year in 96 because they purposely put in the most expensive processor in the most unreliable head unit. When it goes bad, and apparently this is a poorly engineered item, your are looking at some bucks heading their way. There is a guy on Ebay that seems to have a lot of the 97-00 climate control head units - they are cheap and come with warranty. I think that they were rebuilt "cores", so probably do not have the innards of the OEM part. But for $50?? What a deal - and if it works it works! Would this unit fit into the plug/dash of my 96? If there is anyone out there selling the C4 units please let me know

 

I don't believe any of the C5 controls will work on a '96. The only one I've looked at had a different sized head unit, but you can x-reference anything at www.acdelco.com and see what fits what. Be sure to look at the images too, as I belive that they also have a Manual Set Up shown or labeled as a "Programmer" for the '96 - though that may be at one of the Vendor's sites. As far as I know, none of the Head Units are new (they're all rebuilds) and some of the Programmers appear to be too. Most of the '96 members seem to have a problem with the vacuum harness connection - the Programmer is fine, but the harness won't stay together. One thing I would do on these later units (once you rule out the harness) is troubleshoot it with a Bi-directional scanner. That will at least narrow it down and if you don't have one, see what the dealer flat rate is to hook it up (can't imagine more than an hour).