A/C Not Working - Switch Not Lighting up?

[RobertK]

I went through my A/C system yesterday and replaced the high and low pressure switches, pulled a good vacuum, and filled it upwith close to 1.5 cans of 134a.

I checked all the fuses and for some reason I cannot get the A/C to kick on. I;ve tried 3 different switches in the dash. 2 I know are good and when you push the A/C button it will not light up blue and the A/C will not come on.

And ideas?

[AlarmedBread]

Check all your grounds? The hood grounding strap was cut on my car and the AC would not work. Replaced it and now it works fine.

[RobertK]

Check all your grounds? The hood grounding strap was cut on my car and the AC would not work. Replaced it and now it works fine.

That's weird, I never thought that the hood grounding strap did anything important. Can anyone else explain how the A/C is related to the hood grounding strap?

[maco325e]

Try to move the bottom vent slider on the heater control to the right, just some times that will do the the trick. If it doesn't You are gonna have to pull the heater controls out and check behind the sliders there is a plug at the bottom slider check if its broken. Sometimes the little tabs that keep the plug in place breaks,if its broken have to go to the junk yard and get one happened to me.

[rs4pro3]

or splice the two wires directly together on that slider plug.

[rcko]

my hood ground strap is not connected and the ac works... compressor runs...

ck for 12 volts on the compressor 12v plug?

pressure switch plugged in correctly?

[RobertK]

Where is this slider plug that you speak of or am I tarded?

[rs4pro3]

on the back side of the 3 sliders that control where the air flow goes. On the bottom right(looking at the panel from the driver's seat). There is a small 2 pronged plug that presses onto a small board that has tracts on it. For the AC to kick on the lower two levers have to be in a contacting that board. A lot of times the contacts on the board are bad, or the plug is bad. I removed the board altogether and just spliced the wires together. This makes it so you can get AC out any of the 3 vent positions.

[RobertK]

How do I remove that panel to access the wires I need to splice together?

[maco325e]

Before You start looking for the plug, move the foot well lever to the right like half way open.The a/c should kick in. If not then try to go for the plug.

[RobertK]

I slid those sliders every whichway and combo possible with no luck.

I spliced those 2 wires together and it kicked on first try. Now the bad news is I found out my aux fan is on it's death bed.

[maco325e]

Replace the the resistor on aux fan that should do it.

[maco325e]

Or even better try to jump either of the temp switches on radiator to check if the low speed switch is bad.

[RobertK]

It has no problem kicking on.. It just makes all kinds of horrible noise when it does.

[moatilliatta]

i also believe if your system is out of r-12 it wont even kick on. see how much pressure you have.