Question on Charging A/c

[Lefty2053]

Got some Freon last night and went out to try putting it in this morning. I put a wire in the 2 holes of the connector and started up the truck. Turned on the A/C and it still doesn't kick on. Double checked the fuse and it is good. Must be the Compressor is bad.Will look at it agian later today. Possibly the wiring somewhere else is bad.

 

[koda2000]

try running power and ground straight to the compressor from the battery. if the clutch starts spinning you know you've got an electrical problem somewhere. if not, the clutch/field coil is bad. have you tried swapping the A/C relay?

 

[Lefty2053]

try running power and ground straight to the compressor from the battery. if the clutch starts spinning you know you've got an electrical problem somewhere. if not, the clutch/field coil is bad. have you tried swapping the A/C relay?

Tried switching the relays out to all 3 different ones in the box. Nothing changed. So the wires going into the back of the Compressor is what I need to hook up the 12volts to?

Went out and tried that but only had speaker wire to try it with. Nothing happened,so I guess the Compressor is shot.

 

[koda2000]

Tried switching the relays out to all 3 different ones in the box. Nothing changed. So the wires going into the back of the Compressor is what I need to hook up the 12volts to?

Went out and tried that but only had speaker wire to try it with. Nothing happened,so I guess the Compressor is shot.

you want to remove the electrical connector plug at the compressor clutch field coil, then hot-wire the field coil directly to the battery's positive and negative terminals. the engine does not need to be running, the key should be in the OFF position, speaker wire is okay to use for this test. you should hear a loud "click" when you touch the wires to the battery. that's noise is the A/C clutch engaging. it really has nothing to do with the compressor, but if the clutch doesn't engage, the compressor will not run. if the problem is the field coil/clutch, you can just replace the field coil/clutch assembly and you should be good to go. i changed mine a few weeks ago, with the compressor still in the truck. it wasn't that hard to do and cost me around $82 through Advance Auto Parts (using their promo code).

the field coil is an electromagnet. when energized, it engages the A/C clutch, which then turns the compressor shaft. the field coil can go bad, or the clutch surface can wear to the point where the air-gap between the 2 surfaces of the clutch are too far apart and wont engage.

 

[Lefty2053]

Is this what you mean by field Coil/Clutch.
[URL=http://s1196.photobucket.com/user/lefty2053/media/fieldcoilclutch_zps05c83c16.jpg.html][/URL]

Or is it just the last item on the right of the picture?

 

[koda2000]

the field coil is the last item on the right. the center item is the A/C pulley, and the the one on the left is called the A/C clutch hub. when the field coil is energized, it pulls the hub into the pulley, which causes the compressor shaft to turn. when not engaged, the pulley just spins on a bearing with the serpentine belt. it's the hub that spins the compressor shaft. the air gap between the hub and the pulley is critical. on a new clutch assembly it needs to be something like .024-.030. this is acheived by addling or removing small shims to the clutch hub.

 

[Lefty2053]

Have my grandson over here now and when he first turns the car on and then turns the knob to A/C the clutch turns on for only 1 second and then shuts off. It will do this all the time but only when first started. Never a second time while it is running. Turning A/c off and on. I used the wires and got the clutch to click by direct connect to the battery.

So direct to the battery it clicks and when I first turn the car on and then the A/c it engages for one second.

I am assuming it isn't the Coil since it does engage sometimes. So does that mean it is the clutch itself, or a combo of the coil and clutch?

 

[koda2000]

Have my grandson over here now and when he first turns the car on and then turns the knob to A/C the clutch turns on for only 1 second and then shuts off. It will do this all the time but only when first started. Never a second time while it is running. Turning A/c off and on. I used the wires and got the clutch to click by direct connect to the battery.

So direct to the battery it clicks and when I first turn the car on and then the A/c it engages for one second.

I am assuming it isn't the Coil since it does engage sometimes. So does that mean it is the clutch itself, or a combo of the coil and clutch?

that means the clutch and field coil are probably okay. as the clutch engages when the A/C is first turned on, it sounds like the electronics (fuses, relays, wires) are also working. have you tried jumping both the LOW and HIGH pressure switches (individually)? It could be the refrigerant pressure is too LOW (not enough refrigerant) or too HIGH (too much refrigerant) or that one of the switches is not working as it should. the low pressure switch is the one up new the accumulator and the high pressure switch is the one near the battery. if the compressor starts working when you jump either switch, you're narrowing down your issue.

as you can't get the system to take any more refrigerant, maybe you have too much in there. either condition will stop the compressor from engaging.

 

[Lefty2053]

I took a wire and jumped both the high and low switches. Neither one will do anything. Will try one more time. The clutch comes on for that split second and if I am not watching it I would never know it came on. It really doesn't make any noise I can hear when the car is running.

 

[Lefty2053]

If I have too much Freon in the system is there a way to remove some?

 

[koda2000]

If I have too much Freon in the system is there a way to remove some?

wearing rubber gloves and eye protection in a well ventilated area, only way to do it at home is to push down on (or loosen) the schrader valve. just like letting air out of a tire. or you could go to an A/C shop and have them recover it and get your pressure where it's supposed to be. the latter is probably a better idea.

 

[Lefty2053]

wearing rubber gloves and eye protection in a well ventilated area, only way to do it at home is to push down on (or loosen) the schrader valve. just like letting air out of a tire. or you could go to an A/C shop and have them recover it and get your pressure where it's supposed to be. the latter is probably a better idea.

Thanks for all your help on this. I will call around Monday and see if I can find someone that does that.
One other thing I need to add. With the A/c turned to A/c or Max either one. And the Fan setting turned OFF. The Clutch will still come on for a split second when starting the car. I found this out by mistake and think it is weird it does that.

 

[koda2000]

Thanks for all your help on this. I will call around Monday and see if I can find someone that does that.
One other thing I need to add. With the A/c turned to A/c or Max either one. And the Fan setting turned OFF. The Clutch will still come on for a split second when starting the car. I found this out by mistake and think it is weird it does that.

there is no difference between A/C and A/C MAX as far as the compressor is concerned. it's more fresh air ventilation vs recirculation with A/C. for that matter, if you read your owner's manual, it says something like "the compressor may run at any time if it's warmer than 55F, in any setting except VENT". i honestly don't know if it's strange the the A/C clutch comes on for a split second with the fan set to OFF. my guess is that's probably normal.

good luck and let us know what you find out.

 

[Maniak]

If you had a gauge set you could know what is going on (are you over or under charged).

Even without a gauge... I find it odd that it is shutting down even when you have the high and low pressure switches bypassed. With those bypassed the compressor should be running even if the system was empty or even if you had the hoses disconnected. It wouldn't know any better.

Did you try the trick of running power/ground directly to the compressor? If you do that and the compressor doesn't stay on then the clutch is bad. At that point your bypassing everything that "tells" the compressor to run.

~Mark

 

[koda2000]

unless i misunderstood, i believe he connected the clutch directly to the battery and it engaged.

OP - did you run the compressor while connecting it directly to the battery? i know you said it clicked with the engine not running. connected directly to the battery, the compressor should run continuously until you disconnect it.

 

[Lefty2053]

If you had a gauge set you could know what is going on (are you over or under charged).

Even without a gauge... I find it odd that it is shutting down even when you have the high and low pressure switches bypassed. With those bypassed the compressor should be running even if the system was empty or even if you had the hoses disconnected. It wouldn't know any better.

Did you try the trick of running power/ground directly to the compressor? If you do that and the compressor doesn't stay on then the clutch is bad. At that point your bypassing everything that "tells" the compressor to run.

~Mark

Just went out and put some connectors on my wires so they stayed on the Compressor terminals. I started the truck and attached wires to the battery. It keeps the Clutch moving and the A/c got cold fast. I had my Grandson remove the positive and it stopped and the Air warmed up. SO I guess it either has too much or not enough to stay running on its own.

 

[bobflood]

'97 would have been R-134 from factory; no retrofit. I am assuming that you have the automatic climate control. There is a relay inside the unit on the circuit board where the solder joints fail (small black box on one end of board). On mine, it would provide enough current to register a voltage on my digital meter, but not enough to actually operate the compressor relay. It was a real bear to ID, because it looked like it should work from the meter readings, but it didn't actually work. Found out when I swapped meter for test light and light did not illuminate.

You could have the same issue with the circuit board relay; but in your case the initial surge when the unit first cuts on is just enough to operate the relay momentarily. There are two ways to go - either replace the EATC unit (commonly available on line for about $100) or take apart and resolder. I did the later; it was much easier than I expected and the repair has held for a year now. Do some searching on "EATC" and you should find some links. Good luck.

Here you go - check out this thread: http://www.explorerforum.com/forums/showthread.php?t=363745&highlight=EATC

 

[Lefty2053]

'97 would have been R-134 from factory; no retrofit. I am assuming that you have the automatic climate control. There is a relay inside the unit on the circuit board where the solder joints fail (small black box on one end of board). On mine, it would provide enough current to register a voltage on my digital meter, but not enough to actually operate the compressor relay. It was a real bear to ID, because it looked like it should work from the meter readings, but it didn't actually work. Found out when I swapped meter for test light and light did not illuminate.

You could have the same issue with the circuit board relay; but in your case the initial surge when the unit first cuts on is just enough to operate the relay momentarily. There are two ways to go - either replace the EATC unit (commonly available on line for about $100) or take apart and resolder. I did the later; it was much easier than I expected and the repair has held for a year now. Do some searching on "EATC" and you should find some links. Good luck.

Here you go - check out this thread: http://www.explorerforum.com/forums/showthread.php?t=363745&highlight=EATC

Just done reading that. I am still at a loss. Where is the control head? Not familiar with that. If I knew where that was I know I would find the Relay.

 

[bobflood]

Just done reading that. I am still at a loss. Where is the control head? Not familiar with that. If I knew where that was I know I would find the Relay.

The unit I am talking about is the one in the dashboard that has the temp display, control buttons, etc - just below the radio. Again, I am assuming that you have the EATC - Electronic Automatic Temperature Control - and not the manual "three dials" control panel.

 

[Lefty2053]

The unit I am talking about is the one in the dashboard that has the temp display, control buttons, etc - just below the radio. Again, I am assuming that you have the EATC - Electronic Automatic Temperature Control - and not the manual "three dials" control panel.

Just figured it out. No I don't have that function. All manual controls.