Cab Heat & A/C - Gryphon Programmer
 

OK... I've done several searches to see if this was an issue reported previously but haven't been able to find anything. I've searched keywords: "heat", "heater", "temperature", "thermostat"... all to no avail.

So... if it is somewhere please just provide a link. If not... here's the problem...

In short, whenever I have my PCM with stock tune, the in-cab temperature select works incrementally as one would expect. When I have a custom tune loaded (currently 87 Performance), the heat is either off, or on high. There is no gradual mix as I turn up (or down for that matter) the temperature select dial.

I return to stock programming and the temperature select goes back to incremental control.

Just to be clear... I'm referring to the climate temperature control knob in the center of the dash between the fan speed and venting select knobs.

Any ideas? This isn't so much a problem during the hot summer... but during winter it'd be nice to have the windows up without sweating or drying my eyeballs. Just seems odd to have to adjust the in-cab temp with the windows instead of the temperature control.

Thanks,
Rich

I've never heard of this, Rich. My truck has the "climate control" feature too and it works as it should regardless of what tune I'm using.

Mine is electronically controlled and can be adjusted with buttons on the steering wheel as well as "up/down" controls on the dash. Sounds like your controls are a bit different and I don't have a wiring diagram for your truck.

I cannot understand why a "tune" would have this effect in your vehicle.

Possibly, Bill might be able to figure it out if you were able to get hold of him.

- Jack

I didn't think it had anything to do with the tune either. But nothing else changes. If I'm on a stock tune... the temp works like it's supposed to. Load a tune (and doesn't matter which one) and it's either no heat or full heat.

Who'da thunk?!?

So... do I send a msg to Bill directly? I'm trying to go through the proper channels here...

Pic below for reference...
https://picasaweb.google.com/lh/phot...eat=directlink

Mine has always been like that. My switch doesn't have the blue/red gradient though. Mine has the red bar end, make a gap and then the blue bar starts. I'll watch for it next time I have to switch back to stock.

Normally, those kinds of controls mechanically open or close a "bypass" valve in the engine coolant circuit that directs or prevents coolant flow into the heat exchanger that the AC/heater fan pulls air through. If the valve is completely closed, you get no heat. Completely open, full heat and in between, as it opens, increasing warmth mixed with whatever air is passing through.

The only way the PCM could affect this would be by it controlling a motor that regulated the valve, rather than having the mechanical linkage.

Now, climate control DOES use such a motor, so I wonder if Ford uses that kind of actuator on all trucks to simplify production, and, your knob regulates a voltage signal to that motor or something equivalent, which would have you manually doing what my PCM does.

If your truck is like mine, the center section of the instrument panel is dead simple to remove, so you could see if that knob has a mechanical or an electrical connection. Maybe the knob "signals" the PCM to adjust the valve?
---

So, I was "thinking out loud" above. I looked at the wiring diagram for my model year truck and it appears Ford controls heat/cold with a "blend door" that is moved by a motor. There is always coolant going through the heat exchanger in this setup. So, for some reason, I guess your blend door is moving to full heat open as soon as you move the temperature knob off of full cold, or, the AC is completely cut off if the knob is off full cold. :shrug:

And, the PCM is involved in this to a certain extent. Looks to me like it controls the AC clutch, although the diagram is not at all clear to me here. I don't see anything like a temperature control rheostat in the diagram. (It's probably "buried" in the Electronic Manual Temperature Control Module, which I think is the front of what you're looking at on the instrument panel, with the knobs - and it does NOT connect to the PCM. But it does control the blend door.)

That module has three wires going to the blend door actuator. The motor is positioned through a Dark Blue-Light Green and Orange pair and feedback on its position is through a Violet wire.

By now you must be hopelessly confused (I think I am). :giggle: So on the off chance that it helps, I'm including the three pages in the wiring manual that refer to a system like yours in the 2005 truck. Sorry about the quality. It's a scanned copy in a pdf file on my computer and I did a PrintScreen of the three pages that apply.

Oh, DO feel free to contact Bill directly on this. There are no "channels" here.

- Jack

I have had the dash out a number of times and all connectors are electrical. There are no mechanical connections or linkages to speak of. So there must be some PCM going on somewhere. There are 2 connectors... 1 has about 4 wires which appears to be ilumination... A simple straight plug type of connector. The 2nd connector has about 10-12 wires of smaller gauge using a cam-lock type of connector similar in function to how the connectors hook up to the PCM. I've tried to eliminate as many variables as possible. Doesn't matter if it's at idle or at speed, coasting or load... If its stock it works... If its tuned its either hot or not. *sigh*

What's the best way to contact Bill about this? Id hate to have to decide between tuned or climate controls. Really don't want to have to trade 1 for the other.

Thanks again!

Probably, the "Live Chat" feature is the best way to make Bill aware of this. Several people have reported success recently with that.

Does your wiring look at all like the diagrams I posted?

- Jack