I am still thinking of doing the Firebird dash, but may do a Grand Am (easier to find).

My question:

Are the Grand Am & the Firebird HVAC controlls the same? Obviously, diffrent years will present unique challanges, but, on the whole could an interface for those rotary controlls be built & sold?

I am not the best when it comes to the math/formulas for the interface. It would be great to have a "turn key" solution.

Thanks in advance.

John

RCR is in the process of doing a Grand Am dash swap, although I'm not sure if he's done the wiring yet, or if he's converting to the GA controls or is keeping the Fiero controls. You could ask him what he's looked at doing for it.

[EDIT]
Found his thread in tech https://www.fiero.nl/forum/Forum2/HTML/043545.html
[/EDIT]

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Nick www.naskie18.com AIM: Naskie182010

[This message has been edited by naskie18 (edited 11-21-2003).]

Thanks for the help. You have a +.

John

Bump

Wow, this is the first ever thread directed at me, and I almost missed it.

Ironically I have been shopping on eBay looking for a set of environmental controls that would work better than the firebird.

Reason is that the rotary switches that I was able to buy only have 7 positions, that's not enough to line up perfectly with the Firebird controls. I believe the Grand Am has 7 so that might work better.

Also, I prefer having a separate switch for the A/C compressor, (firebird doesn't have that). On my GT I used the rear window defogger as the A/C switch but that wouldn't work as well if the car actually has a rear window defogger.

My circuit that I built converted the rotary inputs into Fiero logic. It's not particularly sophisticated, but it was a pain to build because it has a bunch of relays and diodes.

I'd be more than happy to share my design with anyone who wants to build one...I don't know about actually selling them, to make it commercially viable the cost would probably be higher than anybody would be willing to pay.

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If you find my advice useful, then please give me a positive rating, thanks...

1988 GT (Firebird Interior)
1988 Coupe (Daily Driver),
1985 SE (Project Car) Recent Addition
1985 Coupe (parts car)
Firebird Interior Installation Website

I just made these, hopefully they will be useful to someone contemplating a swap.

I realized after looking at my drawing that I used a 6 position switch. I didn't implement the "VENT" position because it's identical to "NORM" but without A/C. Since I have a separate switch for a/c it would be redundant anyway.

Wow, more infor that I expected!

Thank you!

Though I am still a little leary of doing the controlls. Just a thing that I need to get over....

John

I used the older ('92) Grand Am controls. '95 and up are digital - behind the knob is a potentiometer, not a switch. I trashed the whole idea of using a '95 or later dash because of this. There's a brainbox in the HVAC control unit, and the mixer controls are run by stepping motors.

I used a 12-position rotary switch that had the capability of being 24-position. I then took the switch apart and moved the contactors around until I had a working stop position for each of the indicators on the Grand Am HVAC panel. To get around the indexing of the switch not lining up with the indicators on the panel, I removed the part of the switch that causes it to "click" into position, and used the index built into the GA rotary knob. I was also able to use the circuit in the knob to turn on the AC compressor and the radiator fan.

Total cost not including my time - $2.00 (gotta love army surplus)

The blower fan switch is the same as the Fiero, and the temp mixing door easily works with the GA rotary knob, you just need to connect the cables. I used the defroster button to pop the trunk.

I thought about doing some kind of conversion kit, but AFAIK, nobody else has glued 2 GA dashes together to get them to fit. Looks like RCR will have a better fit with his newer dash, but he will also be doing an engine/ecm swap. The gauges in that dash are controlled by the ECM. I doubt that dash would operate in an otherwise stock Fiero.

Thanks guys!!

John