If you're dealing with AC issues on your 84-89 Mercedes 190D, this GPD pressure switch might be exactly what you need. The part number 1711422 is designed specifically for these models, functioning as both the high and low side pressure switch for your air conditioning system. Installation is straightforward if you're familiar with basic automotive repairs - just make sure to properly evacuate and recharge your AC system according to manufacturer specifications. The build quality is solid, and it's made to OEM standards to ensure proper operation and longevity. I've used this replacement on several 190D models, and it's restored proper AC function every time. The switch accurately monitors pressure levels and engages/disengages the compressor as needed to protect your AC system from damage. If your AC isn't cooling properly, the compressor isn't engaging, or you're experiencing other climate control issues, this pressure switch is one of the common culprits worth checking. It's a genuine GPD part, which means you're getting quality that matches or exceeds the original equipment. For Mercedes owners maintaining these classic models, having reliable replacement parts like this available is crucial for keeping your vehicle in proper working order without paying dealership prices.