Thanks for the info everyone.....

If when I start the car and the A/C is on, the first blast of air discharged is HOT, moments pass and COLD air is disscharged. I hear the compressor kick on and off when I turn the A/C on and off. I also have expiremented with the mode selctor and yes it is working properly, all vent exhausts are available to move the air around.

So I think I can safely say that I have narrowed the list down, problem is I don't know what I have removed from the list, (I don't understand what is written in the list, sorry).

If some one can help me with my ignorance I will be greatfull to them...

One more thing I just remembered.... I noticed one time that the A/C blew only very HOT air until I wigled the wire at the front sensor probe, immediatly after that the A/C went cold....

Ok, Nick...here is what you have so far:

1. External temp sensor fault - located on front of center brace in front of radiator (the sensor you have been wiggling) - Maybe the problem...you did mess with it afterall.
2. Internal temp sensor fault - located behind the guage face panel, behind the slats next to the cigarette lighter on the dash - maybe your problem but doubtful.
3. Solar sensor fault - the black half-dome solar eye located on top of the dashboard, dead center on the dash top - again, maybe, but doubtful.
4. Air mix door fault - located deep behind the dash near the center but behind the glovebox - probably not your problem since you get heat when heat is commanded and A/C when cold is commanded
5. Heat/AC contol panel fault - ECC panel where all the switches are - Not sure yet, but I doubt it.
6. Loss of "keep alive memory" in HVAC programmer- you remember the programmer under the glovebox, behind the dash...the tubes you and I repaired come out of it. - Don't know if you have a problem here, still have more readin' to do
7. Loss of serial data - same as above..more readin' to do.

On your delay of A/C and heat...it is normal for the system to delay operation or purge itself at start-up...the delay can be up to 20 seconds, so I wouldn't worry too much about it at the moment...if I find something that points to these conditions, I'll let you know.

My gut tells me it is the external temp sensor, or more exactly, the wiring coming out of the sensor. You have said it yourself that wiggling it keeps producing changes and that is also when the display started blinking.

The two temp sensors are thermocouples. Unfortunately, you can only 'read' one of them.

Does the external sensor ever read WAY too low? This would indicate a short (low resistance) in the circuit.

Does the external temp sensor ever read WAY too high? This would indicate an open or high resistance in the circuit.

My control just started flashing about 15 seconds after startup and it flashes for a minute and then quits.

The Vent button light is on. Sometimes it'* off at first and then comes on and then goes off after several minutes when the interior is nice and warm. I'm wondering if it'* the control unit and a connection since this happened when the car sat out and was colder than it'* been for a long time when I started out. Sitting in the garage now it still does these same things. But now it'* cooler in the garage than it used to be--45 this morning inside attached garage.

The digital readout has had a brightness problem for a couple of years. Tapping seemed to make it brighten-other times it just brightens and dims at will. Could I have the problem that Regals had with resistors in the control head need resoldering?

Outside temp Okay
Inside temp Okay
Controls all work
Even though vent light is on unit seems to go into recycle mode okay.

Thanks for the help in the info posted so far!

LeSabre 1998 dual auto air

Imi, your brightness issue sounds llike a cold solder joint.

Well I had a chance to check out what we have been tossing around and I found that if I start the car and let it sit for a minute or two the blinking goes away on its own, and if I turn off the engine and then restart the car the same results happen again.
The functionality of the ECC is working like it always had work.
The temp readings on the LCD is no higher or lower than it should be.
I did remove the probe and wiring, checked to make sure the connection was good and tight when I mated the wire to the probe.
I guess I am going to start driving it and see what happens.

I need a suggestion on a brand and type of coolant Antifreeze I should get, I would like to remove the water only coolant as soon as possible, any suggestions? Or should I start another thread about the Antifreeze (I hope not).

OK I don't like the orange dex cool. It is fine for 5 years, then breaks down and starts causing problems for you or the next owner. I would install the "mixes with either" yellow green stuff. Do not put in regular green 'cuz it will form sludge with any residual Dex you may have in your system. My $02.

Nick, upper got here today. I haven't had a chance to look at it yet. Thanks.

I run the green stuff for coolant. No probs yet.

Nick, no sign of failure on this upper. There does seem to be some metal dust in the EGR passage. First time I've seen that. Interestingly, it isn't marked whether it'* a Rochester or Delphi, like all the others I've seen. It was cast 4/1/97.

I'll clean it up, ream it out, and sleeve it later today. One more available, team, PM me.