P38 Air Con Compressor clutch

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
good tips datatek.

i did try the fuses and as the compressor is engaging and then shutting off i figured the HEVAC was ok. i put a jumper in the white/green & white/orange (if i remember correctly) on the triple pressure sensor / trinary switch and 'bingo' the compressor kicks in straight away.

i dont have access to a diagnostics unit so i've plopped for a new OEM pressure sensor £24 quid (new) from a LR parts supplier and will pop that in and hopefully the problem will be solved.. hmmmm.

of course the system will need to be vacated and refilled for fitting it. :mad:
 
Well, I took your advice and bought an MSV2 - now to get on with clearing some faults and getting to the root of my P38's issues! Thanks for the guidance here on the AC side of things, I'll be attempting an investigation this weekend into a "(32) Compressor clutch control circuit open or short to ground" - whatever that means! I suspect it's a dodgy wire. Well, I hope it is ;)
 
RossDagley said:
Well, I took your advice and bought an MSV2 - now to get on with clearing some faults and getting to the root of my P38's issues! Thanks for the guidance here on the AC side of things, I'll be attempting an investigation this weekend into a "(32) Compressor clutch control circuit open or short to ground" - whatever that means! I suspect it's a dodgy wire. Well, I hope it is ;)
Click to expand...

It cannot be both open circuit and shorted to ground. Depending on year, check the compressor clutch relay and fuse box for signs/smells of burning. If yours is the earlier version without a relay suspect the HEVAC unit.
 
Gday from Oz. To ukadamwest, researching same symptoms on my 95 4.6, three other points to check are 1* clutch air-gap excessive (remove spacing shim, or machine clutch face and make new oversize shim). 2* weak power supply via scrawny wire from relay (rig an extra wire from relay output pin on engine bay fuse box or for a quick answer, a 12v hotwire from the battery). 3* burnt relay socket (look and sniff). To check, with aircon on and engine running," help" compressor pulley to engage with firmly held screwdriver Handle at 2 o'clook. Use common sense safety, please. If it stays engaged, try the extra wire first, then consider an air gap correction. This info is from trawling landyzone, rangerovers.net, and aulro.com, my saviour on many infuriating occasions. Glad to be on board.
 
Further to my post yesterday; for the air-gap adjustment, see rangerovers.net/forum "airconditioning erratic january 10th 2008". On the same site," AC Grounding points november 7th 2008" is another detail to eliminate. Cheers, Fixes.
 
I have a 72Kb PDF extract from a Sanden service manual showing compressor clutch disassembly which I will now try to upload. P.S. read the last paragraph re air gap. It's from a Spanish manual download site. Here goes.......
 

Attachments

  • AC clutch repair.pdf
    71.1 KB · Views: 416
fixes..

thank you for the data (and datatek too)

i left the air con problem alone for a spell, though had to get all my faults cleared as an SRS airbag light came on (loose connector) so had all the fault codes read and cleared..

in reading the fault codes it turned out that the Air Con compressor (denso unit) wasnt getting 12v, had a look at the relays and two were browned on the outside, (shoulda checked the simple things first) so just replaced the two with scorch marks and still the clutch isnt firing..

now just to turn the clock back, when i had the A/C system filled, the clutch was engaging for about 2-3 seconds, then releasing.. the trinary switch is new and relays have been replaced..

but still nada on the A/C !!

(it's a 2001 MY 4.6 with the denso pump)
 
Last edited:
ukadamwest said:
fixes..

thank you for the data (and datatek too)

i left the air con problem alone for a spell, though had to get all my faults cleared as an SRS airbag light came on (loose connector) so had all the fault codes read and cleared..

in reading the fault codes it turned out that the Air Con compressor (denso unit) wasnt getting 12v, had a look at the relays and two were browned on the outside, (shoulda checked the simple things first) so just replaced the two with scorch marks and still the clutch isnt firing..

now just to turn the clock back, when i had the A/C system filled, the clutch was engaging for about 2-3 seconds, then releasing.. the trinary switch is new and relays have been replaced..

but still nada on the A/C !!

(it's a 2001 MY 4.6 with the denso pump)
Click to expand...


Fuse box is fecked, common problem.
 
You must log in or register to reply here.

Similar threads

M
Air compressor
Replies
12
Views
946
Mark Piercy
Mark Piercy
C
Air Con
Replies
10
Views
880
Alteredtech
Alteredtech
G
L322 Air Conditioning (I know I know)
Replies
4
Views
614
Girthy
G
Paul Coddington
P38A 2.5 DT manual Clutch Slave
Replies
6
Views
514
Paul Coddington
Paul Coddington
stevebrookman
P38A Thor Temp Sensor.
Replies
5
Views
496
Datatek
Datatek
Back
Top