This is on my wife's 2007 ford fusion.

I have tried trouble shooting the problem and thought I had it solved but I guess not.

Here are my posts from another board for historical reference.

24 April 10:
My wife's 2007 ford fusion's A/C doesn't work. I swapped the 10A fuse that was blown for a new one and it blew immediately. Trouble shot it this morning.

1. System fully connected minus the relay which is where I was probing, I was getting a full circuit to body.

2. Started disconnecting all wire harnesses:

2.a. No ground issue from fuse panel to 1st connection.I
2.b. No ground from 1st connection to 2nd/last connection.
2.c. Ground from last connection to body. The connector is grounded (intentionally) to a bracket on the AC compressor, but the diagram shows a resistor in place. I am getting very little resistance if any. I can't recall the exact amount right now.

3. Reattached all connections and double checked. Ground only when it is attached at to the ground at the connector for the A/C coil, which led me to believe that I had an internal short on the coil.

Fast forward till yesterday:

Well, I thought this was a done deal but no luck. Yesterday I went to the craft shop and purged the A/C. From there I removed the compressor and disassembled the clutch, pulley and coil. Replaced the coil and vacuumed the system down.

I then installed the fuse and attempted to charge the system.....it blew a fuse again!?!?

So after pulling another fuse and trying some things, this is what I have gotten to;
1. With the fuse in, and everything connected on the positive side but the negative side disconnected. The fuse will not blow.

2. Connect the negative side of the harness, boom fuse blows.

I will have to borrow the nice multimeter again and see what the amp draw is.

Attached is the diagram. If you notice, there are only 2 connectors on that circuit, the one immediately after the fuse panel, and the connector at the A/C coil.

Any ideas from someone electrical savvy? I'm stumped....

 

this is just a basic question , but is it suppose to only have a 10 amp fuse in it?

but my thought on the problem is the compressor might be going out and have too much of a load and blowing the 10 amp fuse

 

Yes, 10A per the owners manual and the wiring diagram posted here.

 

This is probably a long shot. I've 'fixed' several Stangs that would blow the accessory fuse. Problem: a coin down in the lighter or power outlet socket grounding it out. kennyg

 

Nope. The ONLY thing on this circuit is the A/C coil. My multimeter only goes to 10A so I can't check its draw. It does have a diode check so I will do that today. I will also get the alldata sheets that have additional info on them for troubleshooting listed next to the A/C coil.

I was sure this would be an easy fix....

 

Did you ever put the resistor in that should be there?

Sounds like infant mortality.

 

Can you pull the whole clutch assembly and take it to a motor repair shop? They can adequately test the clutch for starting load.

 

Huh....It's all one piece. Just a connector leading to/from. Are you supposed to "charge" this similar to a large capacitor?

 

Most places over here would rather just have you buy a whole new compressor. It is rather difficult getting work done here if you're not sprechen the Deutsch.

 

On the diode check, I get zero drop in either direction on the old one. I haven't had a chance to go out to the car and check the one on it. Wouldn't that indicate a short circuit??

 

You should see a 0.7v drop going one way and an open circuit going the other way.

 

Check the Pressure Switch by the Firewall for a Dead Short.

KC

 

I'll have to check again...when I was testing the old one I have no drop and closed circuit both directions. The only thing is that I have the same symptoms (blowing fuses) on the new one. I may have to contact the vendor and see if they will replace it.

KC, The only thing on this circuit is the A/C coil. Everything else seems to be fine. Obviously there may be something you're thinking of that I'm not though. What makes you think it's the pressure switch?

 

Disconnect one end of the diode before measuring to make sure you're testing the right path. Put a continuity tester across the diode. If it conducts in both directions, it's faulty.

 

Check the cooling fan relay. If it is bad it will blow the AC fuse.

 

Let the hunt continue.....