Have just installed another ac/heat control unit, air was checked and was all good said we needed new control unit. It worked for 2 days and then no air, 2days later it is working again. Now once again not working HELP!

 

hi gail,either the hvac blower motor intermittently works like mine(I bet it kicks on when you hit a big bump our slam pass door),or its the fan speed control module/switch, both are located under glove box(above where your feet are on passenger side)2 or 3 black screws hold on that panel,when removed you'll see the blower for the hvac fan,5 or so screws(have battery ground disconnected) unplug fan and replace,go to partsgeek.com 50 bucks for deville hvac fan.easy to do yourself and much cheaper: )

 

We don't have a problem with fan that works great ...it is that it is not blowing cold air when we put the air on. Only will be cold for a few days then no air and then it will kick back in. It looks like the clutch is not kicking on when we have no air. Do you have any idea why it would do that....maybe a relay or switch just don't know!

 

do you know how to pull codes on your car?your car has a built in scanner,codes may show,let me know if you don't know how to get the codes,k.

 

Nope have no idea but will try anything..... Waiting to hear from you.

 

on the dash you'll see 3 buttons,info up/down,info reset,and on/off. with the key in the ignition in the on position with the engine off,push and hold up,reset and on/off buttons simultaneously, the dash will light up and turn off, that enters diagnostic mode when "ALL" appears on message display,let go of the buttons,up/down scrolls,info reset goes back and on/off selects, select all by pushing the on/off button, select codes, and all codes, by doing so it will scan your cars computers,when it detects a problem it will show a code, for ex. pcm p0121, it may show many codes, 2 kinds of codes current and history, you should write down all codes and of current or history, now after codes are checked you can either clear all codes,clear selected codes or clear none,to exit diagnostic mode simply take the key out.its easier than all this writing looks: ) you should post your codes when you get them for others to see to help diagnose the problem, you can also google search the error codes for the definition.

 

anything?

 

Here are the codes we got P1540 (history), IPM B0429 (current), and P0463 (history). Any ideas? Sorry it took so long to get back to you.

 

What are the letters in front of the first code? Needed. The0463 is for malfunctioning fuel gage, prob after down half tank gage goes crazy,I have same problem, the 0429 is HVAC baffle is not responding to commanded position for rear circuit #3. Another problem I have.

 

You prob. Have low coolant level, or bad thermostat switch.