I have a 99 Bonneville SLE, my Hvac control is the standard 3 *** mechanical. My question is : can I change my Hvac controls out with the digital SSEi'*? and will it be simple? Assuming I pop out the dash face plate and remove a couple screws.

not sure about that year but in the 2000+ it requires all components from the SSEi system to include: wire harness, HVAC unit, driver side air mix actuator and so on

Thanx I appreciate any input, anything helps. it couldn't be too different could it?

i highly doubt it would work, i tried the same thing with my GP back then and it never worked

My 98 SE has the digital controls in it. I would think you could switch them out without a problem.

I have the 3 **** controls from my old 95 as a backup in case the digital controls fail, but I've never actually checked to see if it would work or not.

To get it to work, the following things will need to be added for sure:

Outside temperature sensor
Inside temperature sensor
Solar sensor <not the one for the lights either>

I suspect the following things will need to be changed:

The main unit <Duh!>
Actuator
Fan controller

My thoughts?

I seriously doubt this is going to be the cakewalk you are hoping it to be, and would classify it under the "sell the car and buy one that has the toys you want" category. If you insist on pressing on with this retrofit, it would be best to get the input from the gearheads who know these vehicles in and out, and can verify both with them, and factory schematics, exactly what will need to be changed, and what will need to be added.

And as for anathema05, I can't say the news is any better for you either. I would be inclined to pass on what you have, and obtain what you would need.

I don't pretend to know everything on these cars, but I ain't a newbie either.

The different wiring includes a temp sensor that rests behind the front bumper and reports inside the cabin on the outside temperature. There are a few more wirings here and there, and I believe you need more power and ground wires. I wouldn't exactly sell a car to upgrade the HVAC, but I would reserve a good week of transferring wires and parts.

I've researched this thoroughly in the past on approximately this year car. To make the swap, the entire system down to the box mounted on the firewall needs to be swapped over. Then the main car wiring harness needs a bit of work and added items.

I'm pretty sure it can be done, this would require a lot of work though. Pulling the dash, tracing down a lot of wires, running a bunch more etc.

I've done a lot of work and understand wiring well. I'd say this is probably a 3-4 solid day project if I were to do it. And I know how to get the dash out in under 30 min.

Wow, I never knew it was so complicated.

For starters, the manual control has a resistor, the auto has electronics etc. One system cares about the temp inside and regulates temp and fan speed, the other gives no lovin.

The HVAC boxes were different for some of those things.. wiring is different enough.. it'* the one thing that didn't get done to the car.