I have a '99 dodge intrepid w/ the 2.7 liter v6, 135k miles & has manual heat/ac controls.

I was cleaning battery terminals which is located on the passenger side underneath the passenger headlamp, right infront of the wheel. When I put the cables back on the horn honked, it startled me so pulled the cable off. When i reattached it, it honked once ant that was it.

Anyway, now my controls knobs are not working right. I only get air via the defrost vents. I get cold air if the directional control is in the third position, if i move it anywhere else i get hot air. I also noticed that the light in the AC and Defrost switch do not come on.

I've already checked all fuses and even replaced the 10 amp heater fuse and I've switched out the ac relay with the wiper relay (cause they are the same relay). I don't know what else to try, there is not much in my Haynes about the ac/heater control system.

I said the ac & defrost button don't work. No diagnostic lights come on. I have read how to run a self diagnostic on the heat/ac system but but when i try it nothing shows up on my digital odometer.

I read a how-to and one of the things they recommend is to check the vacuum-supply line. where is that located.

Any help will be greatly appreciated.

You need to disconnect the battery cable and let the system reset itself. Leave it disconnected for at least a few minutes.

I haven't had this problem with my 'trep, but it happened a few times with my '95 Stratus. Two or three times, the airflow just got stuck in the defrost vent position. In my case, the other functions would work (heat/air), I just couldn't change the flow.

The controls send a signal that operates a solenoid (I think). Its all electrical based. There's no direct connection.

-Dan

I tried disconnecting both cables and leaving them off 15 min, 1 hr, even overnight still no go.

with the car at room temp,(50' to 80') remove fuse 19 for the fuse panel in the car for 10 min's then reinstall it and start the car, let it run for 5 min's, this will recalibrate it.

It worked for 10 or 15 seconds then it reverted back to the top defrost vents. The solution is so close I can almost taste it. The lights on the AC and RearDefrost buttons still do not come on, if that helps. All suggestions are welcomed.

ps. Thanks Caravanman almost had it.

At this point it might be a bad control unit.

Personally, I always try to do these things myself and save the money of paying a mechanic to replace parts until he gets it working.

In this case it might be worth trying a new part. I've seen heater control units on eBay go for $25 - $35. I've almost bought one myself just to have a spare on hand.

-Dan

Can anyone continue advising on this issue, please. It's driving me crazy!!!!!!

No one seems to know. I have the same problem it seems. But mine never worked properly when I bought the car. I'm struggling to find out a solution. I really don't want to pay the outrageous dealership fees to have them run the codes on their machine. Heres the thread I got going. Same exact problem it seems:

http://www.dodgeintrepid.net/forums/showthread.php?t=76707

I remember a while ago (2 years ish) being able to recaliberate the heater controls by holding either the A/c or defrost someone then it runs thru everything... maybe someone else will remember

Here is the diag instructions from the manual. Its in section 24 page 940 http://www.*****************.net/02lhe/02lheB.pdf You can run the self diagnostic on it and see what it shows you.

My buddy had this problem currently and after testing everything we tried another bcm and it worked so it might be the bcm in your car

Guys, thanks. It was BCM. I replaced it and now everything is working - Code2medic was right.

To everyone who is dealing with this issue - try to match all your car's and donor car's options before replacing BCM (especially SKIM) or you might end up riding your bike before you will find another BCM (or even both PCM and BCM) that will help you start your car.