2000 Deville electrical a/c help!!

[Johnsmail987]

I have a 2000 deville with no power going to the compressor.
The A/c relay is good but no signal to throw relay to close position.
Fans stay on at low speed all the time with key on.
Low pressure A/c switch has power and it has 2 high side switch with no power going to them.

[brcidd]

So is your "service A/C soon" message on -- on the display? If so you have an a/c code set and it needs to be reset so that the compressor can be commanded on- either do it on the display, use a scan tool- or unhook the battery for 10 seconds if you have the low charge code-Then you'll need to find out why the low charge code set-- most likely a leak somewhere- if any other sensor type code exists, (under the ACM codes) then you'll have to fix the sensor- because those come back immediately, and the compressor is automatically shutdown...the computer controls the relay- and it will never allow the compressor to run if there is a code set.....

[Johnsmail987]

Originally Posted by brcidd

So is your "service A/C soon" message on -- on the display? If so you have an a/c code set and it needs to be reset so that the compressor can be commanded on- either do it on the display, use a scan tool- or unhook the battery for 10 seconds if you have the low charge code-Then you'll need to find out why the low charge code set-- most likely a leak somewhere- if any other sensor type code exists, (under the ACM codes) then you'll have to fix the sensor- because those come back immediately, and the compressor is automatically shutdown...the computer controls the relay- and it will never allow the compressor to run if there is a code set.....

How do i use the control to see what code is present? I unplug the battery . no luck , do you think the orfice tube maybe clog? or can i bypass the Ac sensors?

[brcidd]

Turn ignition on- hold the "off" and "warmer" buttons in at the same time for at least 5 seconds until the diagnostic scheme comes up- use the fan speed "higher" for yes and "lower" for no - when it asks you the questions- you are looking for the ACM codes- should be a 4 digit code- and you can reset it when it asks you....you cannot bypass this system and still have a properly working system- I have had to "unbypass" several botched cars-- one would not shut the engine off for about 10 seconds because of a brainless bypasser....