Re: 1998 Sahara Dash Air No clutch engagement

[Willsonrick]

'
On my 98 Sahara 3006, Cat 3126.  I was checking my pressure in the dash AC because it wasn't getting cool at the dash. Thinking I needed to add freon.  Pressure was at 80, too high.   Checked to see if compressor was working and the clutch was not engaged.  Checked fuses and connection to LP cutout switch.  I don't have a meter with me, But before I get all into this,, doesn't the clutch require 12 v to engage?  I just want confirm before I dig in. 


Thanks ahead of time.


Rick Willson 98 Sahara, 3006, 3126 Cat'

[W Taylor Hudson]

'Yes.   An 80 psi static pressure on your system eliminates total lack of charge condition which would open your lo-charge safety switch.  
Once you get your lack of power to the compressor clutch solved and check your refrigerant charge, I noticed the top edge of our receiver dryer has a sight glass in it.  Will take a mirror and bright light to read it from underneath (unless you have a thin midget that can stand between the front cap and the front horizontal member).  Good luck. v/r,
Taylor Hudson‘98 Safari Serengeti (4060), CAT 3126acquired 2018

On Mon, Oct 7, 2019 at 4:40 PM willsonrick@... [Safarifriends] wrote:
 

On my 98 Sahara 3006, Cat 3126.  I was checking my pressure in the dash AC because it wasn't getting cool at the dash. Thinking I needed to add freon.  Pressure was at 80, too high.   Checked to see if compressor was working and the clutch was not engaged.  Checked fuses and connection to LP cutout switch.  I don't have a meter with me, But before I get all into this,, doesn't the clutch require 12 v to engage?  I just want confirm before I dig in. 


Thanks ahead of time.


Rick Willson 98 Sahara, 3006, 3126 Cat

'

[Willsonrick]

'Thanks,gonna check to see if clutch is good by jumping from 12v source to wire going to clutch'
Rick Willson, 98 Sahara 3006,3126 Cat'

[Al Glick]

'To answer your question directly, the AC clutch is powered by 12 volts. There is normally a relay that is engaged to control this circuit.
The static pressure of 80 PSI is high enough that the safety cut up switch on the low pressure side should be on.  You can easily check the switch by removing the wires and using an multi tester to check continuity.
You can also use a 12-volt test wire to activate the clutch circuit directly just for testing. This way you can at least determine that you don't have a bad clutch. The engine does not need to be running to test the clutch this way. 

On Mon, Oct 7, 2019, 2:40 PM willsonrick@... [Safarifriends] wrote:
 
On my 98 Sahara 3006, Cat 3126.  I was checking my pressure in the dash AC because it wasn't getting cool at the dash. Thinking I needed to add freon.  Pressure was at 80, too high.   Checked to see if compressor was working and the clutch was not engaged.  Checked fuses and connection to LP cutout switch.  I don't have a meter with me, But before I get all into this,, doesn't the clutch require 12 v to engage?  I just want confirm before I dig in. 


Thanks ahead of time.


Rick Willson 98 Sahara, 3006, 3126 Cat

'

[Rick Willson]

'Thanks Al. I just finished checking the clutch and compressor. The clutch engaged and the running low side pressure dropped to 40#. Air got cool. One thing eliminated. I'm guessing that the switch is the one located up front. (LP cutout Switch). I borrowed a meter from a neighbor so now I can check it.

Rick Willson, 98 Sahara,3006,3126 Cat

On Tuesday, October 8, 2019, 9:46:37 AM EDT, Al Glick aglicknmex@... [Safarifriends] wrote:

 
To answer your question directly, the AC clutch is powered by 12 volts. There is normally a relay that is engaged to control this circuit.
The static pressure of 80 PSI is high enough that the safety cut up switch on the low pressure side should be on.  You can easily check the switch by removing the wires and using an multi tester to check continuity.
You can also use a 12-volt test wire to activate the clutch circuit directly just for testing. This way you can at least determine that you don't have a bad clutch. The engine does not need to be running to test the clutch this way. 




On Mon, Oct 7, 2019, 2:40 PM willsonrick@... [Safarifriends] wrote:
 

On my 98 Sahara 3006, Cat 3126.  I was checking my pressure in the dash AC because it wasn't getting cool at the dash. Thinking I needed to add freon.  Pressure was at 80, too high.   Checked to see if compressor was working and the clutch was not engaged.  Checked fuses and connection to LP cutout switch.  I don't have a meter with me, But before I get all into this,, doesn't the clutch require 12 v to engage?  I just want confirm before I dig in. 


Thanks ahead of time.


Rick Willson 98 Sahara, 3006, 3126 Cat '

[Willsonrick]

'UPDATE  Checked continuity of LP cutout switch.  0 ohms so its good.  No 12 volt to the LP cutout switch.  Condenser fan it working when I push the AC button on the dash. 
Apparently something else is messed up.  Banging on the dash with forehead did not solve the problem. 
After looking at Jim Exler's Acme drawing in the files, I am going to jumper out the thermostat before I go into the control panel.  
If anyone has any ideas please let me know. 
Thanks
Rick Willson, 98 Sahara,3006,3126 Cat'

[Rick Willson]

'Found it. IT is the thermostat blocking the 12v. Thanks for the hints and encouragement.

Rick Willson, 98 Sahara,3006,3126Cat

On Tuesday, October 8, 2019, 3:12:56 PM EDT, willsonrick@... [Safarifriends] wrote:

 
UPDATE  Checked continuity of LP cutout switch.  0 ohms so its good.  No 12 volt to the LP cutout switch.  Condenser fan it working when I push the AC button on the dash. 
Apparently something else is messed up.  Banging on the dash with forehead did not solve the problem. 
After looking at Jim Exler's Acme drawing in the files, I am going to jumper out the thermostat before I go into the control panel.  
If anyone has any ideas please let me know. 
Thanks
Rick Willson, 98 Sahara,3006,3126 Cat '