Once again I played around with hvac programmer since my heater is on defrost and floor.Have no vacuum leaks but after playing around checking hose nipples and hoses got it to work on middle vents for a/c but still wont for heater,any idea why only a/c?I have read all JR 3800 threads and info checked everything(hoses and nipples good on programmer)the only thing I havent done is bypass the connector.thanks

the ECC will not allow you to put heat out of the center vents. it is a flaw in the system. the first year to allow it is 1995. heat will only come out on defrost or floor.

Are you sure ,I just gave my 89 sse to a buddy I was toying around with vacuum lines and his heater is now blowing out middle,i dont know why it shouldnt, anyone else.

isnt there a way to put a 95+ programmer in the earlier models?

Yes... a 92-94. I don't think that 88-91 would be a direct swap though. Might need to tinker with the vacuum lines and maybe the actuator. Maybe I'll be the first to try 'cause I miss that Mode button.

Shortstuff is right on... well, close. I wouldn't say that it'* a flaw in the system but moreso the way it was engineered. Perhaps the engineers were flawed

As the inside air temp approaches the selected temp on the ECC display, air will be directed to different vents or a combination of vents until only the dash vents are selected. By this time the air mix actuator has been opened and the air feels relatively cool.

So Randman 1 , my ecc is working properly then just like Short stuff said.

please do, for the love of god, do it, i HATE not being able to control where my air goes.

Yes, it sounds like it'* working properly. Try this:

Warm up the car nice and toasty. Starting at 90*, press the temp down repeatedly giving about a second between presses. As the temp setting on the ECC display gets closer to the air temp, you will see it switch modes. I can't remember exactly the mode changes but this is my best guess: From Floor it will switch to Deforst and Floor bi-level then to Vent and Floor bi-level and then to vent. Each time the mode changes, the delivered air will be cooler so by the time it gets to Vent mode, it'* cool.

Thats the thing I only get defrost or floor, no bi level or vent.I do however get vent on a/c.
I gave my 89 sse to a buddy and the same thing no vent for heat the whole time I had it,( a/c dont work).I was helping him with vaccum checks and other problems such as maf sensor was shot,I also cleaned IAC and TB but the vacuum air at idle started to go crazy surging wildly,all of a sudden there was vent heat,we found a maf at the yard now she runs great and he has heat coming out of vent.I thought maybe we unclogged a vacuum line or something cause there didnt seem to be leaks.Anyways Im wondering why cant my 90 sse have vent heat and Shortstuff said 95 was first year to allow heat out of vents.thanks for replying