--- product_id: 4141102 title: "Viair 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black" brand: "viair" price: "1992 som" currency: KGS in_stock: true reviews_count: 13 category: "Viair" url: https://www.desertcart.kg/products/4141102-viair-93940-40-amp-air-compressor-relay-for-12-volt store_origin: KG region: Kyrgyzstan --- # 40 Amp max current Moisture-resistant molded case Four 1/4 inch spade connectors Viair 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black **Brand:** viair **Price:** 1992 som **Availability:** ✅ In Stock ## Summary > ⚡ Elevate your air compressor game with power and precision! ## Quick Answers - **What is this?** Viair 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black by viair - **How much does it cost?** 1992 som with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.kg](https://www.desertcart.kg/products/4141102-viair-93940-40-amp-air-compressor-relay-for-12-volt) ## Best For - viair enthusiasts ## Why This Product - Trusted viair brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Trusted by Pros:** VIAIR’s 1-year warranty and top-tier build quality keep your system running smooth - • **Plug & Play Simplicity:** Four quick-connect spade terminals ensure fast, hassle-free installation - • **Tailored for Precision:** Each compressor requires its own dedicated relay for optimal operation - • **Power Up with Confidence:** Handles up to 40 amps for reliable, high-demand compressor performance - • **Built to Brave the Elements:** Moisture-resistant casing protects your relay in any environment ## Overview The VIAIR 93940 is a robust 40 Amp, 12 Volt air compressor relay designed for seamless integration with automotive compressors. Featuring four 1/4 inch spade connectors and a moisture-resistant molded case, it ensures durable, reliable performance under demanding conditions. Perfect for professional-grade installations, it comes backed by a one-year manufacturer warranty and is highly rated by users for consistent, overheating-free operation. ## Description Viair 40 ampere four-post relay for all 12-volt applications. Review: Exactly what I needed to fix my ARB single compressor - I bought this relay to replace the failed relay in my ARB single air compressor, and it’s been working great. I was a little worried about compatibility at first, but it dropped right in with no issues and got my compressor back up and running immediately. Since installing it, the compressor has been starting normally and running consistently. No weird behavior, no overheating, and no problems after multiple uses. I’ve used it several times now to air up tires and it’s been solid every time. The relay itself feels well made and reliable, which is really all you can ask for in a replacement part like this. If you’re dealing with a bad relay in a compressor or another automotive application, this is a simple and effective fix. I’m very happy with it and would definitely buy it again. Review: Relay - Works in a arb air compressor. ## Features - 40 Amp 12v Relay with Mounting Tabs - Four 1/4 inch spade post connectors - Handles up to 40 amperes maximum ampere draw in applications - Each compressor must have its own relay for a proper installation - Mounting tab for relay molded into moisture resistance relay case ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000YC7GBU | | Best Sellers Rank | #49,726 in Automotive ( See Top 100 in Automotive ) #3 in Automotive Replacement Air Conditioning Compressor Relays | | Brand Name | VIAIR | | Coil Voltage | 12 Volts | | Connector Type | Quick Connect | | Contact Current Rating | 40 Amps | | Contact Material | Silver Nickel | | Contact Type | Normally Open | | Current Rating | 40 Amps | | Customer Reviews | 4.7 4.7 out of 5 stars (621) | | Global Trade Identification Number | 00818114009402 | | Included Components | Per Item Description | | Item Weight | 22.68 g | | Manufacturer | VIAIR | | Maximum Switching Current | 40 Amps | | Maximum Switching Voltage | 12 Volts | | Minimum Switching Voltage | 12 Volts (DC) | | Model | 93940 | | Mounting Type | Chassis Mount | | Number of Terminals | 3 | | Operation Mode | Automatic | | Part Number | 93940 | | UPC | 818114009402 | | Unit Count | 1.0 Count | | Warranty Description | All VIAIR products come with a One Year Manufacturer Defect Warranty | | Wattage | 480 watts | ## Product Details - **Connector Type:** Quick Connect - **Contact Material:** Silver Nickel - **Contact Type:** Normally Open - **Current Rating:** 40 Amps - **Mounting Type:** Chassis Mount ## Images ![Viair 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black - Image 1](https://m.media-amazon.com/images/I/61OsFO9ivIL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: Would this work on a Mercedes benz s430 airmatic compressor** A: is it 40 amps or less then it should **Q: Will this relay work for a Mercedes R350** A: relays see amperage only, so if what you are trying to control does not draw more than the rated amperage of the relay, then yes **Q: I just bought this relay to go with the viair high flow 150 set up. But it only has a pos and neg wire will the relay work?** A: Yes it should work. The purpose of a relay is to allow the use of smaller gauge wire for the pressure switch input from the pressure tank and on/off switch, however, you need to use an appropriately sized wire from your battery or another high amperage source direct to the compressor. The item shown is for 40 amp delivery and if this is the draw for your compressor, you should be looking at wire in the 8 gauge range for both positive and to chassis ground or all the way back to the battery. If the compressor draw is less, like something in the 15 or 20 amp range, you can still use this relay and use 14 gauge (for 15 amp draw) or 12 gauge (for 20 amp draw) for the main positive and negative run to the compressor. As stated above, the ancillary wiring for pressure switch, on/off switch can be much smaller wire gauge. An internet search should have wiring diagram info for high amp devices and possibly the Viair website. Be aware that I am NOT an electrician so do not blindly follow my input. Hope this helps somewhat. **Q: Will it fit a R350** A: that I can't tell. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Exactly what I needed to fix my ARB single compressor *by M***. on December 12, 2025* I bought this relay to replace the failed relay in my ARB single air compressor, and it’s been working great. I was a little worried about compatibility at first, but it dropped right in with no issues and got my compressor back up and running immediately. Since installing it, the compressor has been starting normally and running consistently. No weird behavior, no overheating, and no problems after multiple uses. I’ve used it several times now to air up tires and it’s been solid every time. The relay itself feels well made and reliable, which is really all you can ask for in a replacement part like this. If you’re dealing with a bad relay in a compressor or another automotive application, this is a simple and effective fix. I’m very happy with it and would definitely buy it again. ### ⭐⭐⭐⭐⭐ Relay *by M***T on March 23, 2026* Works in a arb air compressor. ### ⭐⭐⭐⭐⭐ Fixed ARB Twin Compressor *by R***N on April 8, 2026* One of my compressor pumps on my ARB twin compressor was staying on when the switch was turned off. I replaced the relay with this one which is much more affordable than the ARB version. This problem is common if your compressor is installed where there is excessive heat. The relay can get stuck open. Just drill the hole out to 5/16" on the plastic tab and it will fit over the ARB bolt and plug in like the original. ## Frequently Bought Together - Viair 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black - Parts Express 330-075 12 VDC 5-Pin Relay Socket For Bosch Type Relay - Viair 90223 Pressure Switch, Black 1/8 in. NPT (M) 12 gauge --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.kg/products/4141102-viair-93940-40-amp-air-compressor-relay-for-12-volt](https://www.desertcart.kg/products/4141102-viair-93940-40-amp-air-compressor-relay-for-12-volt) --- *Product available on Desertcart Kyrgyzstan* *Store origin: KG* *Last updated: 2026-05-09*