P38A Fault code

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pete12345

pete12345

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Any ideas where to start on my next hevac problem nanocom fault code (32) compressor clutch control circuit open or short to ground these p38s are a never ending battle just replaced the heater matrix and all new blend motors any advice as always much appreciated
 
Unplug the compressor wire on the back of the unit and tap the wire with a 12v supply from the battery, it should click into action. If not the clutch or its supply could the issue. Normally à lack of gas causes a simple none working condition. ;)
 
I thought that don't jump to quickly for lack of gas. jump the AC clutch as @Mark Piercy.

When I did mine it worked and blew cold, so plenty gas:D trianary switch (or whatever its called) it can be tested to narrow down I did.
Got a new 1 and then had it degassed they replaced the switch regassed and hey presto cool as:D.

Have since read it is possible to change the said switch without degas but dont hold me to that.

J
 
marjon said:
I thought that don't jump to quickly for lack of gas. jump the AC clutch as @Mark Piercy.

When I did mine it worked and blew cold, so plenty gas:D trianary switch (or whatever its called) it can be tested to narrow down I did.
Got a new 1 and then had it degassed they replaced the switch regassed and hey presto cool as:D.

Have since read it is possible to change the said switch without degas but dont hold me to that.

J
Click to expand...
I meant just to check the clutch bobine, the system is checked with the correct gear as you know;)
Boing!! ... Just ré read that.... Same page... Note to self.... Learn to read slowly... Ffs:rolleyes:
 
Mark Piercy said:
I meant just to check the clutch bobine, the system is checked with the correct gear as you know;)
Boing!! ... Just ré read that.... Same page... Note to self.... Learn to read slowly... Ffs:rolleyes:
Click to expand...

I dont go near any of that nasty gas either.

:)I jump clutch it worked. I ran engine and jump clutch it got cold. then went looking in Rave for the pressure sensors which can be tested with a meter as to how they are acting:).
It could be low on gas but mine blew freezing cold air, so not a lack of gas.
Dont run for long in that state and you need some heavy wire. there is no control and it just runs flat out cold, its for testing only:D.

J

Note to self refresh before replying:)
 
Check the large white connector behind the passengers kick panel. If certain connections are corroded your compressor will not engage. If corroded the recommended procedure is to cut out the connector and just solder the wires together.
 
pete12345 said:
Any ideas where to start on my next hevac problem nanocom fault code (32) compressor clutch control circuit open or short to ground these p38s are a never ending battle just replaced the heater matrix and all new blend motors any advice as always much appreciated
Click to expand...

That's what I did to fix mine alrhough to be fair I also changed the thermostatic ezpansion valve around the same time. Cannot recall where I got it but it was £30 at the time.
 
I cannot see my clutch in gauging there’s two wires going into the compressor black or white which of these would be the positive I’ve tried a direct live to the both but no movement from the front of the compressor but the fan seems to be blowing a bit cooler after I put in some refrigerant still not completely sure the clutch is working tho
 
Black is usually earth but I cannot recall if it gets 12V to pull it in or goes to 0V. I know it changed from direct from HEVAC control to going via a relay. I also recall seeing something about GEMS aircon on RR.net and wear on something requiring a shim. Not sure which years affected.

Have you tried a recharge? The guys will have to a) drain it and b) run it to recharge it and if there are any issues they'll probably have a good idea of what it is if you take it to proper mechanics - that's how I discovered my TXV was stuffed.
 
Black is the earth.
I take it you are earthing as well as applying 12v?
You should hear the clutch click you wont see any movement without engine running. If the engine is running the center of the compressor pully doesn't turn until the clutch engages.

J
 
It also occurs to me the clutch may not pull in if the gas pressure is too low. However, that can only mean 2 options: 1) the gas has leaked out somewhere, most like the condenser or 2) the TXV is acting up causing it to vent to atmosphere.
 
Grrrrrr said:
It also occurs to me the clutch may not pull in if the gas pressure is too low. However, that can only mean 2 options: 1) the gas has leaked out somewhere, most like the condenser or 2) the TXV is acting up causing it to vent to atmosphere.
Click to expand...

"hotwiring" the clutch it will pull in regardless of gas in system or not. Normal operation you are right. Mine was a duff switch that detects either high or low pressure in which case it all stops working. Mine had defucted to low pressure even with gas. this can be tested with a meter to fid out which way it is switched.
When I jumped my clutch with engine running it got ice cold so I figured there was enough gas that's when I went testing the pressure switch.
There obviously loads of other reason which could stop it running, I just went for the easy stuff first and got lucky;):)

As you have mentiond about the airgap in the clutch, I have also seen that, but am sure you would feel some form of clicking at the clutch but it not pulling in, But I dont know. But if its not doing anything when properly "hotwired" it could well be the clutch as you have said needing shimming, Think its been discussed on here too somewhere.

J
 
I am pretty certain you should hear some amount of click if you direct wire the clutch. You would need to run a jumper wire from black lead to battery negative and another from other wire to battery positive although it is just a coil so polarity doesn't really matter.
I think the deal with the shims was that you sometimes had to remove one to get the clutch to fully engage. It's just an electromagnet and if too far away from its mating surface it can't attach. Perhaps if it was too far away you would not hear a click?
You could insert a multimeter in the circuit to see if the clutch is drawing current or measure its resistance to see if it has gone open circuit.
 
I’m getting no click at all no movement in any direction but no book symbol when you say multimeter where do I take that reading from the plug that goes to the compressor thanks for advise also I may have to remove compressor to take shims out as well then
 
You probably want to use the 10 amp range on the multimeter. The ones I am familiar with require you to plug one of your test leads into a 10 amp position and then switch the rotary selector to 10 amps. You connect one lead of the multimeter to one of the clutch wires. The other multimeter test lead goes to the battery. The other clutch lead goes to the battery as before. If you have a digital multimeter the polarity doesn't matter but you might see negative amps if you have the meter in the wrong leg of the circuit. I think you should see a couple of amps on the meter if the clutch coil is good.
 
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