Hi
we just bought our 2007 suburban. I noticed on the HVAC controls I have a two buttons for rear defrost and button for defogger? What is the difference?
Also the defrost button for rear when I press it, it lights on but does not defrost.
When I press the defogger button it flashes 3 times and does not stay on. I did check the wires on the rear glass and they look fine no damages on both. How can I find out why it is not defrosting and defogger not working? Is there a fuse or relay somewhere?
fogger.thank you

 

3 blinks on the front usually means freon level in system is low. Rear defroster can have an open grid line or bad connection where wire connects to glass. I had to repair that connection in my '11 Tahoe. Use a meter or test light to see if you have power across the two wires that connect to the window.
Full code scan will diagnose the front system with the 3 blinks. Rear window needs the power to it test.

 

Rear window right side connection. I barely touched it and fell off. How do I fix this

 

Been there, done that.
Permatex makes a tab repair kit. I did that on my Tahoe but it did not hold up. I wound up heating up the metal tab so a blob of molten solider stayed on the tab and stuck it onto the window. I then used the Permatex kit's orange copper paste paint to paint around the metal tab to make the connection even better.
It's over a year now and so far so good. I'm in a colder area so every time I remote start the rear defroster goes on automatically so it gets used a lot more weather I like it or not.
Other than that it's change the glass.

 

I cleaned both sides with a wire wheel. Added solder to connector. Held with pliers against window and solder back on. . It works now