Just got a 93 Bronco and can't figure out why AC won't work! The compressor seems free and after doing some investigating, I found I am not getting power to the low pressure switch. The control head has power and is working. I guess my question is...Where do I look next to find the source of my power loss?

 

Does the fan blow at all? If not, it could be the fan motor(I can't think of the technical term to save my life).
I feel your fustration, I can't get mine working either(it's the fan motor and they're a bear to replace).

 

The fan motor works great...temp control seems to work too. At least I get heat on the heat side...just no power to the low pressure switch (located on the passenger side and plugs into the (evaporater??).

 

Huh????????

 

I'll try! Not getting power to the clutch cycling pressure switch which is attached to the suction accumulator/drier...does that make sense?

 

In my profile I have the wiring diagram for the 93 EB Bronco. I went through this also. I had power (wire to ground) at the Low Pressure Switch, but after the switch and before the A/C Clutch, there was a break in the wire. I had to re-wire past the large connector under/near the air filter box. Let me know if you need more help. Also, try searching this forum for posts by my name and you will find one that says "93 5.8 No A/C" I put in everything that I did.

Thankfully, now mine works, and works like a champ.

Tim

 

I meant to say "wiring diagram for a 93 Bronco A/C system"

 

i have the same issue w/ a 96 . no power to start lp switch. could you please give me the color wire you had to re-run...im terrible with wiring diagrams AND have bad vision.

 

here is the thread that I described everything I did.

https://www.ford-trucks.com/forums/5...co-no-a-c.html

There are a couple of key pieces of information that you need to know:
1. If you are checking for power across both wires at you Low Pessure Switch (LPS), you will get nothing. You need to check those wires to ground (from wire to body for ground).
2. If you have a multimeter, check across the LPS wires for continuity (this will tell you if the switch is open or closed because of pressure).
3. If you have power at the connection before the LPS, you can take a test wire from the black wire w/ yellow chaser to one spade terminal of the connection at the a/c clutch. On the spade terminal, run a wire to ground (somewhere on the engine block). Putting the key in run and without starting the engine, place the A/C Heater Control Switch (inside the cab, next to the temp selector switch) to Max A/C, A/C, or Defrost. Any of these will work because they all start the compressor. Once you put the selector on one of those, you will see/hear the clutch on the a/c be activated (pulled back magnetically).
4. Check the continuity on the black wire w/yellow chaser from before the LPS to the A/C Clutch. If you have continuity, then your problem is with the Purple wire that runs to the PCM. If you do not have continuity (which was my problem) then there is a break in that wire somewhere. I ran a wire from after the LPS to after the big connection back below the air filter box. Be sure that you splice before several of the "Y"s.
5. If you need the ALLDATA sheets of the wiring for the A/C system, Private Message me and I will e-mail you better copies of the sheets.

Tim

 

WOW....WAY to hook a brother up !!! i read your previous post about this....went outside....found bl/yel....followed it back and within 2 INCHES of connection, wire was clean broke !!!!! works fine...but DAMN....is that the kinda wiring i have to look forward to ??

THANKS AGAIN....as its hot as can be in FL !!!

 

Happy I could help.

Yes, this is the kind of wiring that you can look forward to.

Go to the store and buy a reel or two of "marine grade, oil resistant" 14 gauge wire, a BUNCH of electrical tape, a handfull of butt connectors, and a case of beer. This will help for future problems...

Tim

 

and redo ALL grounds and wiring ...

 

You all won't believe this! I had the Bronco to the mechanic before I bought it to help me diagnose the problem with the AC. He told me everything was working OK, just not getting power to the LP switch. I messed with the wiring tonight and undid everything through the firewall to the control head and could not find a problem....was very frustrated!! I finally decided to see if I had power to the fuse box, and guess what!!!! No fuse in the damn bos for the AC!!!!! I put in a fuse, cranked up the AC and enjoyed the cold air!!! Sometimes I would just like to kick mechanics ****!! Can't believe he didn't check the fuse. Now all I have left to do is rewrap everything in electrical ta[e and I'm good to go!! Thanks for the replies.