Cannot get 12 volts to A/C clutch?

It must be a bad connection at the fuse panel, as you can see from this wiring diagrams the ACON fuse which if you have 12 volts from it should continue through the relay to the clutch, can you try unplugging the clutch and then measure the voltage? You may have a bad relay or compressor clutch. Check out the images (below). Please let us know what happens.

Thank you, Ken, I searched for some kind of continuity from the orange and brown clutch wire to the relay box. The only hit I got was on a blue wire (shown with pointer). And that wasn't a continual tone of continuity but only a single beep when the probe first touched the wire then it showed 400 mfd afterwards. Confusing but maybe this is the "open" circuit letting partial voltage through I reasoned. So, I ran a new wire from the blue wire at the fuse box directly to the compressor. The result? Still when I jump 12v across A/CON I get nothing to the blue wire that now goes to the AC clutch. I don't understand the inner workings of this fuse/relay box. Another confusing thing in the fuse box is the relay module that the A/CON relay plugs into. It has two connectors plugged into its bottom (one yellow/one white). Following the AC clutch supply voltage across the relay and down through the module the actual prong that is supposed to send 12v to the clutch has no wires going to it from the plug (pictured). This is so confusing because the AC was working and so there has to be some way 12v was getting to the clutch.

Update: So, I wanted to see if the compressor/clutch was good, so I put 12v on the blue wire that I had got the continuity beep on when testing the clutch wire and I got cold AC plus windshield wipers! I couldn't help but laugh at myself. So, I have repaired my blue wire mistake but still have no voltage to the clutch and no idea which wire in the relay box is supposed to supply it.

Update#2: I purchased another fuse/relay box off Ebay (only $25) which was an exact match to mine. Different Sorento accessories make wiring a little different, but fuse box components are exactly the same and most wiring is as well. There is a separate module within the box that holds the AC relay and couple other relays/fuses (see pic) which has 2 plug ins on the bottom of it. On my module just below the AC relay where the AC relay prong goes into the plug there is no clutch wire (see pic). What was interesting is the purchased harness did have a wire in that slot for the AC clutch relay. It's like my AC relay has no clutch wire to send juice through to engage it. But that's impossible! Because we've been running the AC in this car for years! I really don't get it. Makes no sense. I feel like I'm missing something simple, but for the life of me I don't understand this.

So, I don't understand, does the old part have the wires and the new part does not? Also have you checked for voltage at the relay terminals? What happens if you feed 12 volts through the terminal does it get 12 volts at the compressor?

Hi Ken,
I found the problem.
Kia makes 2 different AC compressors for the same models which appear the same but are very different in operation.

One compressor uses a clutch and needs a relay supplying 12v to it. The other compressor uses no clutch, needs no relay, runs continuously but whose pumping capacity is controlled by a swashplate making it a variable pump compressor. It doesn't need 12v to clutch but needs a 5v ref. circuit to send signals to ECU which sends command back to compressor swashplate changing pumping capacity.

My Sorento had this variable pump compressor and needed no 12v to a clutch. Thats why I was getting the 4.8 ECU voltage to the compressor and not 12v.

To confuse things further Kia put an A/CON relay in my fuse box that does nothing! Thats what really threw me off. My set up needed no AC relay and yet one was furnished in the fuse box making it appear that it did.

This led me to purchase the wrong compressor (clutch type) and so I have been trying to make it work in a system it wasn't designed for.

So here I sit with a new clutch compressor in a properly vacuum pumped and leak detected system that works perfectly when engaged but is wrong for the control system.

I think it would be easier to make this clutch compressor work than to take everything out and buy another externally controlled compressor and start over again.

I'm presently looking into that.

Issue Resolved: To follow up I have installed a switch and a relay that controls my clutch type compressor in a Sorento that initially had an externally controlled compressor. controlled by the ECU. This is not the optimum fix as it lacks compressor PSI protection, but it beats the Hell out of riding in a hot car. Everything works as it should. The compressor is either on or off and I get to decide when that is.

Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.