I have an Iveco Daily 35s13 2002 van. When we bought it years ago the guy was very funny about the A/C. He said nah you don't need it I just drive with the window open.
So we eventually got a new compressor, regas etc etc. Long story short is that the electrics in the van are about as reliable as a second hand lawn mower.
The blower fan will come on at random times etc, then not come on at all. We know the system should be full of gas as I had it re gased about 3 times, as it had a crack in the condenser, then it had a leak from the evaporator. I also got it a new pressure switch sensor thing, it sits on top of the filter dryer.
It used to have cool air when driving (if the fan would stay on and not stop) but then when you would be waiting at the traffic lights the air would get really hot. Turned out the electric thermo fans were not turning on because the pressure switch was dead.
Now 6 months on I have not bothered using the AC as it just will not turn on. There is a demon of sorts behind the dash as the horn worked intermittently (now it's dead, blown fuse), the central locking does not work now, and the AC does not work.
What I want to do it bypass the computer as I think it might be the issue. I can tap into the AC relays to turn on the compressor clutch no problem. But the pressure valve, is supposed to stop the compressor when the pressure gets too high, and then start it back up again when the pressure is at a lower safer level.
1. How can I integrate the sensor in my circuit?
2. Are all AC pressure sensors the same?
3. Mine has 4 pins from memory, what do they do? I think when you short two together it engages the cars thermo fan to blow air over when you are stationary.
4. Does the pressure give off a voltage or resistance level that is variable regarding the pressure? If so at what voltage/resistance do I need to make the compressor start or stop? How can I find out what pressure is what voltage or ohm's?
I could just let the compressor run all the time but that is bad because if there is not oil in the system (loss of pressure/gas) then it can destroy the compressor. And I think if there is too much pressure the system will ice up.
(I have had ice come through the vents and land on my arm before, lol
)
I have a few electric components I can use and also a micro controller that I could use the switch the compressor on and off using the input of the pressure sensor.
There is also I read a WOT cut off as well? so that when you rev hard the compressor will not go over a set rpm? I never go over 4000rpm as the motor just will not go, most gear changes are max up to about 3500rpm. (Diesel engine)
Any help would be nice, as it is starting to warm up here now, going to be a stinking hot summer here in Australia soon. And the inside of the windscreen fogs up in the mornings now too with no AC.