lockup won't engage with ac controls engaged

[Tonglebeak]

Perhaps it's due to my broken ac/heat controls, perhaps it isn't. Whenever I have the ac/heat going, the car almost never goes into lockup. I switch everything off, and off she goes right into lockup. With gas prices getting higher and higher it's starting to bother me. Don's shipping me a new set of ac/heat controls, but I'm not sure if the broken controls themselves should be doing this? Anyone know what might be going on here?

[LordDurock]

so the tcc wount lockup

[Tonglebeak]

If the ac or heat is on, and rarely does it lockup. With the ac/heat off, engages just fine.

[CieraSL92]

....The two aren't related. Or they shouldn't be. If you have it set to Vent or HTR, it shouldn't make a difference since the A/C compressor doesn't run. Max Norm Bi-level and Defrost (hot or cold) will trigger an AC request.

The only thing these two have in common is they both signal to or from the ECM. The ECM controls the compressor, and the lockup.

The engine needs to be at operating temperature before the ECM will allow it to lockup, btw. So if your thermostat is sticking open while the heats on.

[Tonglebeak]

So you're pointing towards the thermostat then right?

BTW, when I have the controls set to off, it still blows air out from the under-dash vents, hot or cold depending on what I have the temp set to, if that makes any difference as well...

*can't wait to get functioning controls*

[CieraSL92]

I don't know what I'm pointing too. It doesn't make sense.

The flow-through through the lower vents is normal. It's in the owners manual too. It's called a flow-through ventilation system. The first that had that was a 1940's dodge if I recall.

What I was thinking, Tongle, was that running the heat would take away heat from the coolant, thereby allowing it to cool enough so the ECM would operate in open-loop-therefor no lockup. BUT, with the A/C compressor on, heat would actually be increased because of the stress of the compressor. Plus the t-stat should keep the coolant hot enough to allow closed loop operation.

So I don't know. Maybe a shafted ECM. Def. not the control's. Someone else is going to have to chime in, but you need to be SURE that it's not locking up when the heat or a/c is on.

[Tonglebeak]

I'm positive it's not locking up. There's no way I'm mistaken with this, can't be. Not only do I not feel the so-called "shift", but I don't notice a drop in rpm either.

[CieraSL92]

Ok. here's what i want you to do. Idle the car with heat off and ac off until the fan runs. Slide it over to hot and put it on heat or vent. Set the fan to any speed BUT Hi (so you can hear the RPM's) Drive and see if you can feel the lockup. Check transmission fluid after 5-6 miles of driving (not nessecarily at the same time as you do this) Check to see if it's low, burned, or smells abnormal. Slightly dark red or bright red ideally is fine. While doing the above, drive normally.

Where do you normally feel it lockup? 40MPH on is where you should.

[Tonglebeak]

38 is the absolute minimum i've ever seen it go into lockup. Usually around 40-45 depending on the throttle position.