Muzzys A/C Hack Kit for Ram 1500/2500/3500 (2019–2022) — Heater Core Bypass with Shut-Off Valve, Reversible Install

Muzzys A/C Hack Kit is an easy-to-install heater-core bypass that reduces warm-air bleed into the HVAC system on affected Ram 1500/2500/3500 trucks from 2019–2022.

If your Ram's factory air conditioning blows warmer than expected, this kit addresses a common HVAC design issue without removing the dash or performing invasive repairs. The kit uses a shut-off valve, hose and heavy-duty clamps to reroute heater core flow so less hot coolant mixes into the cabin A/C stream. Components are selected for durability and the installation is reversible — you can restore factory routing at any time.

How does this kit lower cabin air temperature?

The kit partially bypasses the heater core flow when the A/C is in use so less hot coolant circulates through the heater core and into the HVAC plenum. That reduces the amount of warm air the blend door can introduce while the evaporator cools the cabin. Owners commonly report noticeably cooler vent temps after installation.

• Includes a shut-off valve to control heater core coolant flow.
• Replaces the factory heater supply hose connection with a bypass hose and clamps.
• Installs without cutting the dash or modifying electrical components.
• Works for both gas and diesel Ram trucks with the specified model years.

Where do I install the valve on gas and diesel engines?

Installation locations differ between gas and diesel engines but the process is straightforward. For gas trucks, the valve mounts at the engine front on the water pump heater supply hose. For diesel trucks, the valve fits on the heater supply line positioned above the turbo; photos guide the exact routing. Expect to top off a small amount of coolant after reconnecting lines.

• Gas: install valve on the water-pump-side heater supply hose labeled in photos.
• Diesel: mount valve on the heater supply line above the turbo as shown in images.
• Use included hose and stainless-style clamps for secure, leak-free connections.
• Refill coolant to factory level after installation; minor fluid loss is normal.

Will installing this kit harm my truck or void warranties?

The kit is designed to be non-destructive and reversible so it does not require cutting dash components or altering factory electronics. Because it connects to coolant hoses and uses standard clamps, it can be removed to return the truck to its original configuration. As with any aftermarket modification, check your vehicle warranty and dealer policies before installation.

• No dash removal required — installation is external under the hood.
• Uses industry-standard hoses and clamps that can be reversed if needed.
• Rated components minimize risk of leaks or check-engine triggers.
• Consult your dealer about warranty implications prior to modifying coolant routing.

How long does installation take and what tools do I need?

Most installations take under an hour for anyone comfortable working under the hood. Basic hand tools and pliers for hose clamps are sufficient; no specialty tools or cutting are required. Photographic guidance included with the kit shows exact connection points for both gas and diesel Ram engines.

• Typical install time: 30–60 minutes for a mechanically inclined DIYer.
• Tools: pliers, screwdrivers or socket for hose clamps, and a coolant catch pan.
• Includes hose, shut-off valve, and clamps so you won’t need extra parts.
• Follow steps to top off coolant and check for leaks after initial run.

Who is this for: technicians, experienced DIY truck owners, and Ram drivers who notice warm or weak A/C performance and want a low-effort, reversible fix. If you prefer an under-the-hood solution that avoids removing the dash and uses durable parts, the Muzzys A/C Hack Kit offers a targeted way to reduce heater core bleed into the cabin air stream on affected Ram 1500/2500/3500 models from 2019–2022.