Tricky A/C problem with Ford truck

[JohnnyG]

My brother has a 2003 Ford Ranger XLT that has a strange issue with the A/c, hoping someone can offer some help.
The a/c won't come on immediately when starting out, it was taking 18 - 25 miles of driving and then it would start cooling, and get very cold.
Yesterday, the ambient temps in Raleigh were in the 80's, and it only took 8 miles of driving before it started cooling and then got very cold in the truck.

I told him that I suspect a low state of charge, and the pressure sensor wouldn't allow the compressor clutch to kick in until underhood temps raised the pressure in the system.

At this point he hasn't had a set of gauges put on and checked charge level.
Has anyone ever experienced an issue like this on a Ford product? Does anyone else have any suggestions on what the issue could be and what to check next?

 

[atikovi]

Make sure it's in recirc mode for maximum cooling. If underhood temperatures raise the pressure enough for the compressor to kick on, then it's way low on freon and it will never get very cold as you say it does. Sounds like it could just be a little low on charge but gauges are needed to check that.

 

[Dave9]

Gauge on it to check charge level is next. If low, add some dye with recharge to see if you find leaks. If not low, see if low pressure switch is working properly or needs replaced. If switch is working, see if the wiring to the control module is good.

 

[brages]

Need to do some actual troubleshooting to home in on the problem.

My first step would be to see if the compressor is turning on and staying on.

My 97 Ranger had a bad low pressure switch, a cheap and easy fix (it can be removed without evacuating the system).

 

[Nukeman7]

You must first verify the compressor clutch is not engaging when it is not getting cool. Then, use a 12V test light or voltmeter to see if the clutch magnet is receiving current if the clutch is not engaging. Many older Ford A/C clutch spring disc plates get rusty on the inner face, thereby causing the tolerance to exceed what the powered electromagnet can retract for engagement. Often, this issue can be remedied by unbolting the spring disc and removing the rust with a wire brush or a Scotch Brite pad. Be careful to not lose the small thin shim washer(s) that are used to adjust the clutch disc to magnet air gap.


If the clutch is fully engaging properly, check the R-134 refrigerant level for a low charge.

 

[JohnnyG]

OK, thanks everyone. I have made him aware of all your replies. He needs to do a little work now to troubleshoot.

 

[JohnnyG]

Just for follow up.
Pressures checked out fine. So while searching for the outside temp sensor, decided to check the A/C clutch relay. Swapped it with the one next to it and ....Fixed.
Either a bad relay or bad contact in fuse panel.