HVAC problem

[Roger1965]

I did a search but didn't find anything like what is going on in my car:

1) No heat unless I put unit in High setting. Then I get full blast heat.
2) No A/C unless I hit snowflake, then I get full cold A/C

In auto mode fan comes on full speed with no heat or ac, regardless of temperature selected.

The way I have been using it is to leave temp at 85 in manual mode, which just gives me fan with no heat or AC. Then if I want heat one click up puts me in high, where I get full heat. One click down from high gets me back to 85, turns off the heat and puts me back in fan mode. If I want AC, I just hit the snowflake.

Also odd is in manual mode the unit says "Manuell' on the display



I have replaced the little sensor fan on the passenger side of the dash but I can't tell if it comes on

[Timco]

Sounds like climate controller. You won't have AC without the snowflake, but should be able to control fan speed. I've heard of issues with the blend door sticking too or losing its styrofoam surface. As for Manuell, either yours was made in Mexico and is a knockoff car, or that's German spelling.

[911monty]

If I understand you correctly, I'm thinking your car is just fine. Mine does the same thing. It's kinda like my wife with the AC in the house........If you put the temp on 60 it'll cool faster! LOL.:roll eyes:
When you place controller in Auto it will go to max to attempt to reach set point as quickly as possible, which means max fan and max ac or heat. Then when set point is reached it will modulate as appropriate to maintain temp. If the top is open the blower will remain on max speed, unless set point is reached. But I might be wrong, wouldn't be the first time.

edit; Yes the one thing the engineers appear to have insisted on is that manual be spelled correctly.

[Roger1965]

Originally Posted by 911monty

If I understand you correctly, I'm thinking your car is just fine. Mine does the same thing. It's kinda like my wife with the AC in the house........If you put the temp on 60 it'll cool faster! LOL.:roll eyes:
When you place controller in Auto it will go to max to attempt to reach set point as quickly as possible, which means max fan and max ac or heat. Then when set point is reached it will modulate as appropriate to maintain temp. If the top is open the blower will remain on max speed, unless set point is reached. But I might be wrong, wouldn't be the first time.

edit; Yes the one thing the engineers appear to have insisted on is that manual be spelled correctly.

No, thats not how my car is working. In auto mode I NEVER get any AC or heat, regardless of temp selected. I only get heat, any heat at all, when I select high. Even if it's 30 degrees outside and I have it on 85, no heat at all. I flick it up to high and only then the heat comes on. The problem is the heat is all or nothing, so I constantly have to flick it on and off. It does not modulate.

And even if it is 100 degrees out, the AC only comes on if I hit the snowflake manually, even if I set it to 65.

When the top is down, I just turn it off, as I have on all my convertibles.

I guess I'll try a new control unit.

[911monty]

Ok. Just wanted to make sure before you spent money and time needlessly. Good Luck with the control unit.

[Timco]

The snowflake part is correct. Even in auto, it won't add any AC unless the snowflake is displayed.

[911monty]

Just to be clear and I don't think year makes any difference, but with everything off, when I press the AUTO button 3 things happen on the display. AUTO displays on the top left. the temp set point shows and the snowflake appears to the lower left. The blower also comes on. I do not have to press the snowflake to turn on the AC and the AC does not cycle on and off when set point is attained. Mine is a 98. Yours should be similar.

[Roger1965]

Snowflake never comes on unless I press snowflake button. If I hit auto, fan comes on at full speed setting, no heat or ac regardless of temp set or exterior temperature.

Heat comes on only when I put temp at high setting. And then it is so hot in the car after a couple of minutes I click it down to 85, and heat turns off.

If I set temp at 68 and hit auto, I get full speed fan with no ac or heat, doesn't matter if it's 35 or 85 outside.

AC comes on only when I hit snowflake button.

Nothing cycles automatically. I have to make any changes manually by pushing buttons.

Fan speed buttons work fine. It could be the temp sensor in the dash. I replaced it but didn't bench test the old or "new" one.

[911monty]

Do you have a Durametric available? I think you need one to help. I don't think your AUTO is functioning correctly. Could be the temp probe as you say or the controller. A durametric should give you any fault codes and the ability to check what the temp probe is currently sending as well as cycle some of the functions.

[Roger1965]

Yeah, definately plan to get a durametric. I've been wanting one to monitor my cam deviation.

But first I need to get a laptop! LOL

I've been living on my ipad so long my laptop is outdated.

[911monty]

The Durametric website has the minimum requirements to run the software. I know win7 is still ok. i use an old Dell as my garage computer. I'd say you need to scan for codes before replacing parts. Although there was/is a controller in the FS section.