How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Juan Crespo Your Own Question
Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Cadillac
Satisfied Customers: 1526
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
Type Your Cadillac Question Here...
Juan Crespo is online now
A new question is answered every 9 seconds

Have air but no heat what are possible fixes

Customer Question

Have air but no heat what are possible fixes
Submitted: 1 year ago.
Category: Cadillac
Expert:  Juan Crespo replied 1 year ago.

Hi there. Welcome to our site!


If you’re thinking on working on the vehicle yourself, all my knowledge and resources won’t help unless you…

… have basic mechanical knowledge and skills, and…

… have whatever tools and equipment might be needed for a proper diagnosis


There are many things that can cause you to have air but no heat in your Cadillac from faulty controls (both mechanical and electrical) to lack of coolant flow through the heater core, to faulty air distribution components and more. The good thing about your car is that the HVAC system has self-diagnostic capabilities which might give us an idea of what is not working as it should. Once we have a starting point, we can then look at possible fixes.

Here is how to enter self-diagnosis using your control panel:

Entering Self-Diagnostics (With Climate Control Center)

Turn ignition switch to ON position. Press OFF button and WARMER button (standard A/C-heater system), or OFF button and PASSENGER
WARMER button (dual zone A/C-heater system). See attached Fig. 1. Press LO fan speed (down arrow) button until "ACM?" is displayed. Press HI fan
speed (up arrow) until "ACM CODES?" is displayed. Press HI fan speed (up arrow) until DTCs are displayed.

NOTE: Self-diagnostics only allows viewing and clearing of DTCs. Testing and overriding A/C system operations
can only be accomplished using a scan tool.

Please let me know what you find and we can continue from there.

Best Regards.