Welcome to the forum

Fuse #18 in cab fuse box is for AC power to compressor.

It runs to the AC control switch on the dash

When you turn on the AC that 12volts runs thru the dash switch and then thru the two pressure switches to the AC Relay, AND the computer
If relay is closed then that 12v goes to the Compressor
AC relay is always closed when key is on, it only OPENS to cut off compressor at WOT(wide open throttle), to give driver maximum engine power.

If idle changes when you turn on the AC then that 12volts is passing thru the dash switch and thru the Pressure switches to the computer.
So you are down to AC Relay not passing the 12v or the Compressors clutch not engaging when it gets 12v

In my schematic it shows computer getting the 12v after passing thru the pressure switches, but................that is not always the case, lol, sometimes its wired so computer gets the 12v from the dash switch directly, so could be pressure switch problem.


There are two pressure switches, pull the connector off one and put in a jumper wire, then see if AC compressor works, if so replace that pressure switch IF you are SURE the pressure is good in the system

If compressor doesn't work then replace connector and do the same on the next pressure switch

If compressor still doesn't work then you can jumper both at the same time and see if you have TWO bad pressure switches which is long odds, lol.

Fuse 18(12v)-----------dash switch-----(purple wire)-----pressure switch------(red/yellow wire)----pressure switch---(Green/orange wire)----AC relay---------(12v)compressor-----ground

Don't forget compressor clutch needs a good ground

 

Thank you!! I've been a long time creeper, looking at threads and such. Usually pretty confident in figuring things out, but this A/C has been kicking my butt lol.

This is the most helpful information I've received yet, on fixing this issue. Thank you so much!

Quick question, some of these wires, would they run near the radio wires? Owner before me did a complete hack job of installing a head unit, when investigating
some issues with the radio I saw there was quite a few wires cut, I assume some would be from the factory harness and not needed but seemed like a lot of unused
wires lol.

thanks again!

 

There is a White/purple stripe wire that runs from fuse #18 in cab fuse box to the back of Climate Control switch, thats the 12v that is passed to the pressure switches when AC is turned on
It is sent out of climate control switch on the purple wire in above diagram, thru firewall to first pressure switch

So if either of those 2 wires were cut then no 12v to compressor
All the other wires are in the engine bay


There are radio wiring diagrams here: Ford Ranger Radio Wiring Diagram

So you can see what was cut

below is diagram I have for 1996 AC

 

Okay that's good news. I should be good, looking at the schematic. I'll reply back on here on what I find.

Thanks again!