Dometic 40A 3-Pole 24V Replacement Contactor - OEM Air Conditioner Part - Part# 290336557

The Dometic 40A 3-Pole 24V Replacement Contactor (Part #290336557) is a genuine OEM electrical component designed for Dometic RV air conditioning systems. This heavy-duty contactor controls the compressor and fan motor circuits in your AC unit, switching high-amperage loads safely and reliably. If your RV air conditioner won't start, runs intermittently, or makes clicking sounds without cooling, a failed contactor is often the culprit. This direct replacement part restores proper operation to your climate control system.

Key Features

• 40-Amp Rating: Handles high current loads required by RV air conditioner compressors and fan motors
• 3-Pole Configuration: Controls multiple circuits simultaneously for complete AC system operation
• 24-Volt Coil: Compatible with standard RV thermostat and control board voltage
• Genuine OEM Part: Factory-spec replacement ensures proper fit and reliable performance
• Heavy-Duty Construction: Built to withstand the vibration and temperature extremes of RV environments
• Direct Replacement: Installs in place of worn or failed original contactor with existing wiring

Technical Specifications

Frequently Asked Questions

How do I know if my contactor needs replacement?

Common symptoms include: AC won't start even though the thermostat calls for cooling, you hear clicking but no compressor operation, intermittent cooling that stops and starts randomly, or visible pitting/burning on the contactor contacts. If your AC hums but doesn't cool, the contactor may be stuck or welded closed.

Can I install this contactor myself?

If you're comfortable working with electrical components and can safely disconnect shore power, this is a straightforward replacement. The contactor typically mounts inside the AC unit's electrical compartment. Take a photo of the existing wiring before disconnecting, then transfer wires to the same terminals on the new contactor. Always disconnect all power sources before working on electrical components.

What's the difference between 24V and 120V contactors?

The voltage rating refers to the coil that activates the contactor, not the load it switches. This 24V coil is controlled by your RV's thermostat or control board. The contacts themselves switch 120V AC power to the compressor and fans. Using the wrong coil voltage will prevent the contactor from operating properly.

Will this work with my Dometic air conditioner model?

This contactor is used across many Dometic RV air conditioner models. To verify compatibility, check your existing contactor for part number 290336557, or verify the specifications match: 40A rating, 3-pole configuration, and 24V coil. If you're unsure, our parts specialists can help identify the correct contactor for your specific AC unit.

Why Choose Elkhart RV Parts?

We specialize in hard-to-find Dometic RV parts that keep your systems running. Located in Elkhart, Indiana—the RV capital of the world—we understand the urgency when your air conditioning fails. We stock genuine OEM replacement parts and ship fast so you can get back to comfortable camping. Our parts specialists know Dometic systems inside and out and are here to help you identify the exact component you need. When you need it done right the first time, trust the Dometic experts at Elkhart RV Parts.