Hi I'm a newbe here! I just bought a 97 ranger 103669 miles and in good shape. Guy said AC don't work had it fixed last year but it quit, someone told him might need re-charged.
When I turn on Max AC, and fan on it will kick the clutch on and right back off. I thought maybe needs charged but if he had it fixed in a shop last year then it must have a hell of a leak, if he's telling the truth.
I don't have access to gauges till tomorrow, I do have the gauge(low side) that comes with a can of r134a from autozone. When it is put on it will go all way to red then back down to white just below the 20 mark on the gauge.
The clutch on AC even kicks on and off if I put it on front panel air control and switch the temp control all way to hot, that I don't under stand? The only time AC clutch will not try and engage is if floor air control (heater) is on and temp turned all way to hot and when turned off. Weird cause I never seen that before. Also does it if I use the defrost, I do know that defrost will engage the AC unit even in the winter to dry out moister in the air.
I am mechanically inclined but have not did alot of AC work before. my 1st time adding r134a I learned the hard way, Following the youtube videos and over charged my impala and had to have it let out. won't do that no more.
looking for suggestions on what to check in to. I don't have a trusted mechanic where I have moved and need to know something so I don't get over charged.
Or with proper gauges some guides on what to do, I can check pressures, add small amount of refrigerant if needed,
But what else to check? relays or what else besides low coolant can cause AC to kick on and off constantly.
I have read about clogged orfice tube?

Another guy was like me couldn't get a reading cause the needle on the re-charge kit kept bouncing (like mine) and left it on and running for awhile and finally clutch stayed engaged, seen it was low and was able to add coolant. I'm scared to leave on to long for fear of hurting the compressor or to just just add coolant!
also it's 90 degrees out! Thanks to anyone who helps!!

The search function on this forum does not work well for me unless I just can't word this correctly

 

Welcome to the forum.

You do need the gauge set to diagnose AC system.

Good read here for that: Troubleshooting with Gauges FAQ

AC pressure varies with outside temp, by alot, so keep that in mind.

When adding refrigerant make sure it has color added, usually green, this can help you find possible leaks.

AC is not complicated, image here: http://georgemullerauto.com/wp-conte...ing-system.jpg

Compressor takes low pressure refrigerant and makes it high pressure, which makes it very hot, the Expansion valve changes it back to low pressure which causes it to cool very rapidly, then the now low pressure refrigerant goes back to compressor to be changed to high pressure.
Home AC, refrigerators and freezers all work the same way.


MAX AC just means the Fresh Air vent is closed and Cab air is being recirculated, so it has nothing to do with the actual AC system itself, it is a vent setting.

AC compressor usually only cycles on when AC or Defrost is selected, but it really depends on the Climate Control system, '97 is around the time when Ford started involving the Computer in AC control, so can't say if it is normal for Compressor to kick on in other settings.
As you said it is used to Dry the air in the cab, so could be used anytime for that.

 

thanks!I used a set of plastic manifold gauges today and I got some more r134a in, it didn't have dye in it, it came from a big container from a friends car lot. The compressor will stay on now and at about 90 F low side was a bit over 38 when I left and high side was about 230 psi.
Seemed like everytime I would give it gas the compressor would cycle off until I let off the gas. Is that normal? Doesn't seem like it to me.

I bought me a set of AC manifold gauges later today from Harbor Freight. When I hooked them up they read about 45 on low side and 230 on high side at about 87 F outside. Again as soon as I would rev the motor up a bit to about 2000 rpm (no tac, just a guess) the compressor would kick off. That's not normal is it?

I then turned everything off and got rid of a little bit of the r134a till it was on 32 low side and around 210 on high side at 86F. Vent was blowing out cold air (about 55 with metal meat thermometer) and compressor stayed on all the time while idling. When I rev up gas a bit it cut off but this time cut back on while foot stayed on gas.

I do not see leaks anywhere around the ac lines.

Compressors are supposed to cut on and off sometimes, right? Again everything was on max ac and fan on high.
I wonder am I done or do I need to find out why it kicks off when reved up?

 

Yes compressors are suppose to cycle off and on.
If high side gets too high compressor will cycle off because system has enough pressure to operate, high side pressure switch is often called the Cycle switch.

Low side switch will usually only cycle off if system is low on refrigerant, compressor "sucks" refrigerant in and if there is none then compressor can be damaged, which is why there is a low side pressure switch.


What did the gauges show when you raised RPMs, you never said, just said compressor cut off?

And with the 2.3l 4cyl engine, not a power house, Ford may have added software to the computer to cycle compressor off when doing any accelerating, not just at WOT(wide open throttle) like V6 AC systems do.
But just guessing at that.

Difference between AC and MAX AC just the fresh air vent door, it is open with AC, and closed with MAX AC, it doesn't effect compressor operation.
Fan/blower speed doesn't effect AC compressor.