---
product_id: 4141102
title: "93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black"
brand: "viair"
price: "$U726"
currency: UYU
in_stock: true
url: https://www.desertcart.uy/products/4141102-93940-40-amp-air-compressor-relay-for-12-volt-compressor
store_origin: UY
region: Uruguay
---

# 40A max draw Moisture resistant 4 spade connectors 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black

**Brand:** viair
**Price:** $U726
**Availability:** ✅ In Stock

## Summary

> 🔧 Elevate Your Air Game with Precision!

## Quick Answers

- **What is this?** 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black by viair
- **How much does it cost?** $U726 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.uy](https://www.desertcart.uy/products/4141102-93940-40-amp-air-compressor-relay-for-12-volt-compressor)

## 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

- • **Durable Design:** Molded moisture-resistant case for longevity.
- • **Easy Installation:** Includes mounting tabs for hassle-free setup.
- • **Powerful Performance:** Handles up to 40 amperes for robust applications.
- • **Reliable Connectivity:** Equipped with four 1/4 inch spade post connectors.
- • **Optimized for Efficiency:** Each compressor requires its own relay for peak performance.

## Overview

The Viair 93940 40 Amp Air Compressor Relay is designed for 12-volt compressors, featuring a robust 40-amp capacity, four spade connectors for easy wiring, and a moisture-resistant case for durability. Perfect for ensuring optimal performance in your air compressor setup.

## Description

Viair 93940 40 Amp Air Compressor Relay for 12 Volt compressor , Black

## 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

## Product Details

- **Connector Type:** Quick Connect
- **Contact Material:** Silver Nickel
- **Contact Type:** Normally Open
- **Current Rating:** 40 Amps
- **Mounting Type:** Chassis Mount

## Images

![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.

## 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

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*Product available on Desertcart Uruguay*
*Store origin: UY*
*Last updated: 2026-01-31*