no heat or ac nothing
 

I have a 91 deville and i have no haet or nothing. I have checked all of the fuses and there good. When i put it on auto the service ac light comes on. i have nothing. Where should i start.

RE: no heat or ac nothing
 

here are many places to start but you can hold the off and warm buttons for a few seconds if you have a digital dash and look at the fuel display for any f codes like F_ _ .

RE: no heat or ac nothing
 

Go into the On Board Diagnotics by pressing the Off and Warmer buttons on the climate control at the same time to access the trouble codes (hold the buttons for about 4 seconds until the entire display lights up, this will work whether you have an analog or digital dash - the engine should be off when you do this). Write down all the trouble codes that appear (depending on the car - they will appear in the Climate Control or the Information Center). The following website will identify what the codes are: http://members.accessus.net/~090/dtcobd1.html

Write back with any questions.