Air conditioning pressure switch

EZoilburner

03 2500 158wb HR
I pull this code from the van the other day B1003, points to the pressure switch for the A/C. Any way to test it? I'm not sure if removing it will loose all the r134a in the system. I did connect the gauges on it and there is good pressure on the low side 30psi but the high side is the same when it should be above 230psi I think if it was working properly.
Note: I normally do not use A/C but My wife was with Me and I turned it ON. It worked flawlessly until I turned off the engine, turned it back ON and 'nothing' just warm air.

Any tips? I've been reading old threads but points to different issues. Thanks.
 

lindenengineering

Well-known member
Caution
DO NOT in any circumstances attempt to remove the binary pressure switch before a full draw down of the system. The switch is open to the system.

Removal without heeding this can cause severe personal injury from burns and possible loss of eyesight if you are not wearing protective facial/eye wear. Refrigerant when released into the atmosphere will boil and contact onto the skin causes severe burns.

That stated simply remove the socket when the engine is running & A/C is switched to hear the A/C condenser fan activate (if its not seized or the big 40amp fuse blown in the fuse box under the seat.)

(You may even see the system run for a short while once the fan is working and the clutch engages.)

If this is the case my advise is to get the system drawn down, weight the refrigerant contents and charge to the correct spec of 1.90 lbs of R134a (TIN models) before you do anything else. Then use an infrared leak tester to check for leaks.
Dennis
 

EZoilburner

03 2500 158wb HR
The clutch will not engage when I turn the ac ON, the pressure seems ok on the lower side but not so on the high side. I not sure it is a leak, any way to bypass this switch and engage the clutch for a few seconds?

Thanks.
 

bc339

New member
The pressure transducer is not a switch that is used in older or other a/c designs that can be jumper wired to make the compressor engage. The transducer converts the pressure into an electrical resistance that is used by the ATC (automatic climate control). The ATC is a micro controller or mini computer that manages all the climate functions more expensively than the simple sytems of the days of yore.

An easier test would be to first unplug the single wire that is connected to the compressor. The connector pulls straight out. You may need to loosen the small fastener that secures the connector socket on the compressor first. This is what engages the clutch on the compressor. If all the signals from the various transducers and sensors are good, the ATC sends 12 volts down this wire to engage the clutch on the compressor.

If 12 volts isn't present - A/C switch on, engine running - it could be the transducer or the ATC panel that are the problem.

You could also check the clutch operation by using a jumper wire into the compressor connector. I would highly recommend a 12 volt wire with a 3 amp fuse instead of a hot wire. This will help protect the clutch (and you and your Sprinter) from frying if the wire accidentally grounds.

Bruce
 

EZoilburner

03 2500 158wb HR
An update here, it was a bad wire at the ac pump. I pulled the little bolt holding the ac clutch wire and as I did this the pump end of the wire lost all the insulation, I pulled further to avoid contacting any metal and started the engine then turned ON the AC and the clutch engages no problem And the air coming out the vent is COLD as it was before, I only turned the ac on once before bc I was transporting pressious cargo I don't normally use the air conditioning in the sprinter. Here is a pic.
 

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