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- - ? For those with working a/c (https://landroverforums.com/forum/discovery-i-39/those-working-c-78262/)

? For those with working a/c

Can you spin the clutch on the compressor while truck is off? My ac works when it wants to, I'm going to drain and refill system and see if that works.

Quote:

Originally Posted by Sam95disco (Post 558679)

Can you spin the clutch on the compressor while truck is off? My ac works when it wants to, I'm going to drain and refill system and see if that works.

Clutch pulley should spin easily as idlers do when truck off and belt is removed. A failed bearing can take out clutch. Failing bearing can cause intermittent clutch engagement. Replacement bearings should be available and relatively easy ti change.
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if you are going to touch your system, it is not just drain and refill.
you must pull a vacuum between otherwise it is all for nothing.
when you do pull a vacuum it should hold for 30-minutes @ 28 inches of vacuum,
if not you have a leak.

Quote:

Originally Posted by drowssap (Post 558732)

you must pull a vacuum between otherwise it is all for nothing.

And this helps get the moisture out of the system. You want there to be mostly refrigerant in there, no air or water if possible. I had a co-worker tell me about doing some A/C work on his daughter's car once, and he complained that it just didn't blow very cold afterwards. I asked about the vacuum, and he said he used a hand pump. I told him that just wouldn't do it, so I let him borrow my 6cfm A/C vacuum pump. He said it worked perfect afterward, and that was the only thing he did differently.

Ok, so I went to a local flea market to have ac checked. Guy checked the pressure and found out that the compressor is not gettin power to it. All fuses checked out ok. When the ac switch is turned on you can hear the engine rev up a little. When you turn it off the engine revs down. This also happens when ac is on and the max ac button( one with the snow flake icon) is pushed in.

Is there a relay for the ac? Could it be the ac control unit?

Quote:

Is there a relay for the ac?

Looks like K108 is the clutch relay. There's additional trouble shooting info in the Rave Discovery Electrical Troubleshooting Manual if a meter reader and have downloaded manual.
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Quote:

Originally Posted by number9 (Post 563074)

Looks like K108 is the clutch relay. There's additional trouble shooting info in the Rave Discovery Electrical Troubleshooting Manual if a meter reader and have downloaded manual.
......

Checked the control unit, it had current.

Had some spare relays, no go on that. I jumped the compressor straight from battery, it came right on.

If I created a fused switch to the comp would that be ok?

I know the system is regulated, other components make the comp go off and on with an ac system that has no issues right?

Quote:

I know the system is regulated, other components make the comp go off and on with an ac system that has no issues right?

Quote:

A thermostat is fitted in the airflow out of the
evaporator to sense the temperature of the exterior
fins. Should ice begin to form, due to a too cold
condition, it will signal to disengage the
electro-mechanical clutch on the compressor.

Dual pressure switch
This switch, located in the high pressure line between
the receiver drier and the expansion valve, monitors
refrigerant pressure and by means of the relay module
controls the following system functions:
1. Refrigerant pressure drops below 2.0 bar, 29
lbf/in2 (due to possible leakage), the
compressor’s electro-mechanical clutch is
dis-engaged.
When pressure rises above 2.0 bar, 29 lbf/in2 the
compressor’s clutch is re-engaged.
2. Refrigerant pressure rises above 32 bar, 455
lbf/in2 (due to possible blockage), even with
cooling fan operation, the compressor’s
electro-mechanical clutch is dis-engaged.
When the pressure drops below 26 bar, 375
lbf/in2 the compressor clutch is re-engaged.

Unsure what issues you may encounter by eliminating control by thermostat and pressure switch. System may freeze up or compressor could be overloaded.
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Quote:

Originally Posted by number9 (Post 563091)

Unsure what issues you may encounter by eliminating control by thermostat and pressure switch. System may freeze up or compressor could be overloaded.
......

Damn. I'll check all relays later. This sucks.

Found the right relay, thanks for the help number.