P38A A/C
- Thread starter Dopey
- Start date
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tomcat59alan
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Could be,do you have power to the compressor? it needs a grant from the HEVAC to the tri pressure switch to send power to it IMMIC.does the compressor clutch click when its powered? may be just a break in the wire from the switch to the comp.
tomcat59alan
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A grant voltage from the hevac to the switch.
tomcat59alan
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It looks like an ostrich that's lost its beak.
RangeRoller dt
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Our buddy workonP38 bound to have vids on AC dopes
RangeRoller dt
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Lift the bonnet and look at the center of the compressor pulley, is it turning when AC on?
J
Hi Dopey,
turn down the HEVAC temp, make sure air con is on, is compressor "boss" turning within the pulley. If not, touch it with a (ferrous) spanner. Is it magnetised? If so, then wack the clutch plate with said spanner, and the clutch will most likely engage. If the plate was not magnetised, then see if you have a voltage at the compressor. If not, then for now, jump the clutch and see if you get the clutch to a. magnetise and b. engage. if that works, then you need to investigate why you have no voltage at the compressor. Not sure with EDC, but in nano gems you can see both the ac request (to the ECM) and the ac grant). If you can see both of those then the signal runs via the pressure switch on top of the dryer, to the compressor,. Thor uses a relay too, GEMS not, diesel not sure.
If you don't have ac charge the pressure switch will be "open", and the compressor clutch won't receive voltage. It's hard to access, but if you bridge the terminals on the trinary switch (ie bypass the pressure switch) you may be able to get voltage to the compressor. If that works (and this was my problem) then you can replace the trinary switch without evacuating the ac system - I just used a 2nd hand part, but it may be a bumper off job.
If you see 12 v at the compressor (keep an eye on voltage drop, if you have less than 12v the clutch may only be partially efficient) and the clutch doesn't engage, then the quick one is to get some stiff filter paper and run it between the plates on the clutch - will most likely remove a lot of crud. Clutch may well engage after this - mine did. If it still proves stubborn then you may have to remove a shim - not too difficult - but no need if it cleans up ok. You can put a feeler gauge int the gap too - there are settings in RAVE, but I don't have them to hand.
This for GEMS, but I assume it's not too dissimilar for your diesel
turn down the HEVAC temp, make sure air con is on, is compressor "boss" turning within the pulley. If not, touch it with a (ferrous) spanner. Is it magnetised? If so, then wack the clutch plate with said spanner, and the clutch will most likely engage. If the plate was not magnetised, then see if you have a voltage at the compressor. If not, then for now, jump the clutch and see if you get the clutch to a. magnetise and b. engage. if that works, then you need to investigate why you have no voltage at the compressor. Not sure with EDC, but in nano gems you can see both the ac request (to the ECM) and the ac grant). If you can see both of those then the signal runs via the pressure switch on top of the dryer, to the compressor,. Thor uses a relay too, GEMS not, diesel not sure.
If you don't have ac charge the pressure switch will be "open", and the compressor clutch won't receive voltage. It's hard to access, but if you bridge the terminals on the trinary switch (ie bypass the pressure switch) you may be able to get voltage to the compressor. If that works (and this was my problem) then you can replace the trinary switch without evacuating the ac system - I just used a 2nd hand part, but it may be a bumper off job.
If you see 12 v at the compressor (keep an eye on voltage drop, if you have less than 12v the clutch may only be partially efficient) and the clutch doesn't engage, then the quick one is to get some stiff filter paper and run it between the plates on the clutch - will most likely remove a lot of crud. Clutch may well engage after this - mine did. If it still proves stubborn then you may have to remove a shim - not too difficult - but no need if it cleans up ok. You can put a feeler gauge int the gap too - there are settings in RAVE, but I don't have them to hand.
This for GEMS, but I assume it's not too dissimilar for your diesel
Sorry to hear. None if this really "under", btw, only if you have to pull the bumper
brianp38dse
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On the dozzel the compressor is on the side if the block under the turbo so access is lay on your back and arms up from underneath, i messed about with the clutch on mine before i swapped it out for a used one, its a right fiddle, i will pop round and give him a hand as i know what is where.
@brianp38dse you save my life again, thanks so much m8
brianp38dse
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I will give you a ring in the morning.
