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95 Buick PA Climate Control Temp Flashes

When I turn on the car the internal temp number flashes for about a minute. The AC blows cold and I haven’t noticed any issues with the HVAC system. Why is it flashing?

More than likely the display or the chip that drives it is flaky. Or the connection is bad. Once it heats up it works.

I don’t think this is it. It flashes like it’s trying to tell me something. I’ve read some other places online that it’s a signal that the module?.. is bad?

Give this a try!

-Turn the ignition switch on, but don’t start the car.
-Hit the OFF button twice on the climate control.
-Turn the ignition switch off and wait 30 seconds.
-Turn the ignition switch back on again, but still don’t start the car.
-Wait 3 minutes before starting the car and trying out the climate control.

If a temp or blend door actuator is bad it will caues this.

knfenimore, Sorry I never responded to this… I tried what you suggested and it worked… the flashing has stopped. Now I have another issue… the thermostat/temp control display is saying the outside temperature is 156… A couple weeks ago this problem started… it started by saying the temp was 106… it has gradually gone up over the past couple weeks… now we’re approaching 160.
It also appears that I can’t control/set the climate control in between the two extremes… that is to say I can set the temp at 60 or 90… but not in between. I can set the display so that it reads 72 for example, but it feels not different then 60… likewise, I can set it to 80… but not until I set it to 90 does it change to blowing heat.
What is going on here?
Nate Taylor

Everything is pointing to the airmix actuator. The airmix doesn’t use vacuum, it is purely stepper-motor driven. The only thing that is vac driven is the air diverter flaps. This would cause it to only work in max cold or hot. Also, here is a video and it looks as it you are reading coolant temp.

That’s a pretty cool video… I’ll have to check that out… I suspected I was looking at coolant temp… 2 questions. Why is it displaying coolant temp… when I didn’t ask it to do this… and then, are you thinking I need to replace the airmix actuator/motor then? Is that a job I can do? I replaced a blend door actuator in my 98 olds intrigue a couple years ago.

I think you need to replace the actuator. The video shows how to get in and out of mtc mode. When you reset it, it probably defaulted into mtc mode.

The display started acting up a couple weeks ago… I reset it a month ago… So there was a time of at least a couple weeks when it was acting normal…I can’t clear it out of mtc mode now… which I actully wonder if it IS in mtc mode now… I cant’ toggle through any of the other codes/settings/readings… I wonder if the unit is going bad. I’ve tried resetting the unit (following the instructions you gave me originally… nothing happens.

OP writes

"the thermostat/temp control display is saying the outside temperature is 156"

I think Ray would say “doesn’t anyone screen these calls!!!” … lol … just when you think you’ve seen every problem a car could have, yet another appears …