Hey there,
Summer is around the corner and my AC is not working, clutch not engaging.
No visible errors in either the control panel or the unit (VCDS).
Address 08: Auto HVAC Labels: 7M0-907-040.lbl
Part No: 7M0 907 040 BG
Component: CLIMATRONIC MPV V112
Coding: 00014
Shop #: WSC 00020
VCID: 71F0C227F1A9EABAE00E0B9-4918
No fault code found.
However, does anyone have a correct diagram for this model?
No rear AC equipped. Automatic, petrol.
Also, while checking fuses I found that some are missing, specifically these.
Description from https://www.fordmpv.com/smf2/ford-galaxy-reference-library/ford-galaxy-mk1-fuse-box-diagram-1425/
#4 Immobiliser
#16 Thermo switch, cooling fan speed 1
#18 Thermo switch, cooling fan speed 2, air condition, extended run
#24 Booster heater (diesel)
So, the #24 I understand why it's missing, but what about the others?
Should they be there on this particular vehicle/model?
Don't know about the fuses but not all fuses are applicable for all models.
Have you checked the basics like refrigerant in system and operation of the low/high pressure switch? And also operation of air con relays as these would stop clutch energising. Thinking about it are you getting a feed to the clutch actuator wires?
Quote from: johnnyroper on May 12, 2016, 07:31:29 PM
Don't know about the fuses but not all fuses are applicable for all models.
Have you checked the basics like refrigerant in system and operation of the low/high pressure switch? And also operation of air con relays as these would stop clutch energising. Thinking about it are you getting a feed to the clutch actuator wires?
I have checked that there's gas in both the high/low pressure side, but not exactly what pressure, yet.
I was hoping to find a wiring diagram so I could identify the relays and check them.
Low gas pressure is the most common cause for non working AC
Quote from: Chrispb on May 12, 2016, 11:14:54 PM
Low gas pressure is the most common cause for non working AC
Thanks, solid advice, both of you.
I checked the gas pressure with a low cost gauge (I guess it works good enough), and I'm at around 45 PSI low pressure isde.
Checking voltage (see picture) at the compressor and sure enough I have 14V.
I assume this is the only power going to the clutch, as in, the clutch mechanism is broken inside the compressor?
On the up-side I guess that means all AC-electronics are working fine?
Sorry, couldn't edit,
but a small update.
I measured the pins on the compressor and they are at first 0 Ohms, but then stabilized at ~3.2 Ohms, both ways.
Did you check the voltage with earth lead on to plug earth or just to body?
If you checked plug earth then as you are getting 14v at compressor that proves either the clutch or wiring to the clutch are at fault,looks like a compressor change then unless the clutch is available as a separate item?
And yes proves electrics are functioning correctly if feed down to compressor.
Quote from: johnnyroper on May 13, 2016, 03:47:00 PM
Did you check the voltage with earth lead on to plug earth or just to body?
If you checked plug earth then as you are getting 14v at compressor that proves either the clutch or wiring to the clutch are at fault,looks like a compressor change then unless the clutch is available as a separate item?
And yes proves electrics are functioning correctly if feed down to compressor.
Checked inside the plug, and no rust or debris blocking the connection to the compressor.
I'm thinking about replacing the compressor, the cost for a new one is about $240 here.
And some overhead for new gaskets and vacuum/refilling.
In that case it's compressor clutch knackered then,if you get it all unbolted but leave pipes on you could save some money getting a mobile air con man to come and evacuate system change compressor over and have vac down and recharge done all in one hit. Otherwise you would need to pay for evacuation and then a again for vac and charge I would think?
45psi sounds low to me
Is it running on 134a ?
How did you manage to get the reading ? Do you have the correct connectors ?
Air con have trip with lp low pressure and hp high pressure. Running I would say your figure is getting there but static its lost gas
If there is 14v at plug to compressor there must be enough refrigerant not to open the low pressure switch even if it is on the low side.
Quote from: johnnyroper on May 13, 2016, 11:47:47 PM
If there is 14v at plug to compressor there must be enough refrigerant not to open the low pressure switch even if it is on the low side.
Thanks for your help!
I am now 100% sure it's the compressor at fault. I put the ECC on cold and full blow and tapped the clutch disc - and it sucked in and the AC started spinning.
When I pressed ECON it disengaged, but wont engage again unless I tap the disc.
Perhaps if I boost the voltage it'll engage... hehe.
Ok small update yet again!
I was able to remove the outer disc on the AC clutch and remove the 1 shim that was inside.
After reinstalling without said shim, the AC clutch engages/disengages correctly! (ECON off/on for testing).
However, next problem.. :)
When checking the high and low pressure sides (with the AC on cold and full fan) the pressure remains static on both sides.
Does this indicate low gas so it cant work correctly, or simply internal compressor failure?
See attached picture for pressure readings.
There must be enough fridge in system as the pressure switch allows clutch to energise.
Equalising of pressures is usually internal failure of the compressor,if it's not been running for a while then the seals could have dried out inside. Either that of the shim you removed is allowing clutch to engage but not actually operate the compressor?
Not sure on exact figures for a gal but on a working system you want to see roughly 30-50psi on low side and 190-250psi on high side