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 John Your Own Question
John, GMC Technician
Category: GM
Satisfied Customers: 9176
Experience:  ASE MASTER TECHNICIAN/40 years experience
Type Your GM Question Here...
John is online now
A new question is answered every 9 seconds

1999 GMC: climate control..all switches and relays also brain ecm

Customer Question

I have 1999 GMC Jimmy With climate control it works intermitely some time works fine have replaced all switches and relays also brain ecm thermstatic switchs pressure
Submitted: 8 years ago.
Category: GM
Expert:  John replied 8 years ago.


Can you explain your problem in detail,exactly what does not work,when it does not work,& approx. how often this occurs ?


Any symptoms that occur along with this problem might be helpful.

Customer: replied 8 years ago.
It Happens intermitly push a/c button it flashes 3 times and compressor doesnt come on sometimes when driving it will decide to come on when it does it might work for 10 min or sometimres work for a day or 2
Expert:  John replied 8 years ago.
Your automatic climate control system is also controlled by other computers in your vehicle(BCM,PCM).All of these circuits,sensors,computers,& actuators have to communicate for proper operation.The first thing that should be done is to scan all (especially BCM) vehicle computers.The flashing button lights is a sign that circuit failure has occurred .This has to be diagnosed with a scan tool for clearing the failure & viewing data parameters of the system.