Best Auxiliary Heater & AC Control Relays of 2026

The Dorman 904-300 Intake Heater Relay is a durable and trustworthy replacement part that is designed to match the fit and function of the original relay for select Dodge/Ram models. This relay is made from quality components to ensure reliable performance and a long service life, making it the ideal solution for damaged or failed original parts due to fatigue. To ensure the perfect fit, input your vehicle's make, model, and trim level into the garage tool.

This Car Auto Heater Ducting Warm Air Vent Outlet is made of durable plastic material, and is compatible with 75mm Warm Air Vent Outlets. It can prevent your car surface from scratches and dust, and is a great replacement for your old or broken one.

The Xximuim Rotatable Air Vent is designed with durable plastic that resists wear, corrosion, and deformation, ensuring long-lasting use. Its 360-degree rotation feature lets you easily direct warm air exactly where you want it, providing comfort tailored to your needs. This vent also protects your car’s air outlet from scratches and dust, keeping it clean and in good condition. Installation is hassle-free, requiring no drilling or special tools, so you can set it up quickly and start enjoying better air flow without any modifications.

The Dorman 904-356 Intake Heater Relay is a direct replacement for the original engine air intake heater relay on select Dodge models. This relay is an ideal solution for a damaged or failed original part and is made from quality components for reliable performance and a long service life. To ensure proper fit, input your vehicle's make, model, and trim level into the garage tool. Backed by a team of product experts with over 100 years of automotive experience, you can trust the quality of this durable construction relay.

The Dorman 904-308 Intake Heater Relay is a direct replacement for the original part on specified Dodge models. The relay is made from quality components to ensure reliable performance and long service life. It is the ideal solution for a damaged or failed original part. To ensure fit, users can input their make, model, and trim level into the garage tool. Backed by a team of product experts in the United States and over a century of automotive experience, this relay is trustworthy and reliable.

EATAKWARD Relay is a top-quality replacement part for Dodge RAM 2500 and 3500 models from 1994 to 2002. It offers OE quality components, ensuring long-lasting performance in extreme conditions. The perfect fit and function save you time during installation. Say goodbye to cold start problems with this relay, preventing issues like unable cycle off or inlet heater errors. Its wide compatibility makes it a reliable choice for your vehicle.

The Xspeedonline Dodge RAM Heater Relay is designed to meet or exceed original equipment standards, ensuring reliable performance you can trust. This relay is thoroughly tested during manufacturing, so you won’t have to worry about faulty parts. It directly replaces several part numbers, making it easy to find the right fit for your vehicle. Perfect for 1994-2002 Dodge Ram 2500 and 3500 diesel models, this relay supports your engine’s air intake heater system, helping your diesel engine start smoothly in cold conditions. If you’re unsure about compatibility, the detailed photos and part numbers help you confirm the right product for your needs.

The Casalytics Atwood Relay is designed as a direct replacement for specific Atwood water heater parts, ensuring it fits your system perfectly without hassle. It supports a high electrical load of 30 amps, which means it can handle the power needed to reliably ignite and operate your RV’s water heater, helping you avoid unexpected failures. Its Single Pole Single Throw (Normally Open) design provides steady and safe power flow, making sure your water heater starts quickly and efficiently. Built tough with silver-alloy contacts and a heat-resistant case, this relay can endure extreme temperatures and vibrations, giving you dependable performance in your RV environment.

The Packard Heat Sequencer Relay is designed to handle up to 25 Amps at both 120 and 240 Volts, ensuring reliable performance in your heating and cooling systems. Its full-load rated auxiliary contacts enhance the relay's functionality, allowing you to control additional components efficiently. Built to resist shock and vibration, this solid-state device ensures durability and longevity, making it a smart investment for your HVAC needs. The quick-connect terminals simplify installation, saving you time and effort while ensuring a secure connection.

The X AUTOHAUX Intake Manifold Heater Relay is a reliable and sturdy accessory designed for Dodge RAM 2500 and 3500 with 5.9L L6 Diesel engines from 1994 to 2002. This intake heater relay is built with high-quality components to ensure a prolonged service life and excellent performance even in extreme conditions. By replacing your old or damaged relay with this one, you can avoid cold start problems, cycle off issues, and inlet heater errors. The direct bolt-on installation makes it easy to replace, providing you with the convenience of a quick and hassle-free upgrade. With the X AUTOHAUX Intake Manifold Heater Relay, you can ensure a smooth and reliable start for your vehicle.