---
product_id: 5009905
title: "Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241)"
brand: "flex-a-lite"
price: "R6821"
currency: ZAR
in_stock: true
reviews_count: 6
url: https://www.desertcart.co.za/products/5009905-variable-speed-control-module-with-stainless-steel-temperature-probe-31165
store_origin: ZA
region: South Africa
---

# Reduced charging spikes 60-100% variable fan speed Precision temp sensing Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241)

**Brand:** flex-a-lite
**Price:** R6821
**Availability:** ✅ In Stock

## Summary

> 🌬️ Stay cool, stay ahead — control your engine’s climate like a pro!

## Quick Answers

- **What is this?** Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241) by flex-a-lite
- **How much does it cost?** R6821 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/5009905-variable-speed-control-module-with-stainless-steel-temperature-probe-31165)

## Best For

- flex-a-lite enthusiasts

## Why This Product

- Trusted flex-a-lite brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Durable Build:** Stainless steel temperature probe and machined exterior ensure long-lasting, reliable performance.
- • **Post-Drive Cooling:** Keeps fans running for 30 seconds after shutdown to prevent overheating and extend engine life.
- • **Seamless Integration:** Includes A/C relay and manual override switch connections for full control and compatibility.
- • **Power System Friendly:** Minimizes charging spikes and reduces electrical load, protecting your vehicle’s charging system.
- • **Smart Thermal Control:** Automatically adjusts fan speed from 60% to 100% based on coolant temperature for optimal engine cooling.

## Overview

The Flex-A-Lite Variable Speed Control Module with Stainless Steel Temperature Probe intelligently senses coolant temperature to modulate fan speed between 60% and 100%, enhancing cooling efficiency. It features a post-shutdown fan run for 30 seconds to prevent heat soak, reduces electrical charging spikes, and supports A/C relay and manual override connections. Built with durable materials and designed for easy surface mount installation, this module ensures reliable, optimized engine cooling and electrical system protection.

## Description

Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241)

## Features

- One Flex-A-Lite Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241)
- Senses coolant temperature and sets fan speed 60-100% for better cooling control
- This controller directs cooling fans to run for 30 seconds after vehicle is turned off
- Reduces charging spikes and current load on charging system
- Includes A/C relay and manual override switch connections

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Connector Type | Through Hole Or Surface Mount |
| Contact Material | Silver Alloy |
| Contact Type | Normally Open |
| Mounting Type | Surface Mount |
| Brand | Flex-a-lite |
| Operation Mode | Manual |
| UPC | 088657802390 088657311656 |
| Global Trade Identification Number | 00088657802390, 00088657311656 |
| Manufacturer | Flex-a-lite |
| Model | 31165 |
| Item Weight | 1 pounds |
| Product Dimensions | 8 x 6 x 4.5 inches |
| Country of Origin | USA |
| Item model number | FLE123241 |
| Is Discontinued By Manufacturer | No |
| Exterior | Machined |
| Manufacturer Part Number | 31165 |
| OEM Part Number | N |

## Product Details

- **Connector Type:** Through Hole Or Surface Mount
- **Contact Material:** Silver Alloy
- **Contact Type:** Normally Open
- **Mounting Type:** Surface Mount
- **Brand:** Flex-a-lite

## Images

![Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241) - Image 1](https://m.media-amazon.com/images/I/71UN+G9n5DL.jpg)

## Questions & Answers

**Q: Can one temperature sensor be used to provide input to two controllers?**
A: Unfortunately, no, you can't use just one sensor for two controls.

**Q: Can this sustain enough power to run two flex-a-lite 398 syclone black 16" s- with out burning up**
A: I believe so. I was running two 16" fans as well and had no problems.  I DID however burn up my alternator from lack of airflow by taking out the cooling fan.

**Q: Can the length of the probe's wiring be extended if necessary?**
A: Yes, it can. You will just want to make sure you solder the joints of the extensions.

**Q: Will this work with stock 05+ Silverado dual fans?**
A: This has not worked the right way for me. I now have my 2 fans set-up so they come on when I start my truck up. I hope you have better luck than I did.

## Customer Reviews

### ⭐⭐⭐⭐⭐ This controller does a great job and comes supplied with everything needed to get'r done.
*by Z***N on June 20, 2018*

I rebuilt my 2000 Wrangler 4.0 Sport cooling system. This included a high-flow water pump, high-flow thermostat housing, thermostat (stayed 195) and several hoses. I left the OEM radiator as the last thing to change if I needed too. It turned out unnecessary due to the 485.I'm using the Black Magic model 485 @3400CFM fan with this controller.The 485 fan can be found here:Flex-a-lite 485 Direct-Fit Black Magic X-Treme electric fan for '87-'06 Jeep WranglerAfter getting everything routed and configured the way I wanted I've now had several days of thorough testing. Even the first day included over 4 hours sitting in the scorching sun with the AC turned on, so it's been fairly tested already and this is just the early stages.When I say scorching, I'm talking 106+ heat index Texas. It's blazing and still climbing, the primary reason I wound up in the market rebuilding my cooling system. It's been a fun project and the results are great.At this moment I'm extremely happy with the controller. My vehicle cooling is now absolutely top notch and staying precisely where I want it at all times.The soft start is outstanding and a feature all fan controllers should implement.The build quality of the controller is simple but appears very effective. Previous revisions according to reviews had several issues. They appear to have been resolved in this latest revision. The result is a solid, more reliable controller.It's weather resistant but not weather proof. This is going to be important to people that bog their front clip through soupy mud, rivers or any other situation where moisture and corrosion can impact modules under the hood.Although I never saw anyone do this in the hundreds (yes hundreds) of reviews I've read about this controller before purchase, I personally decided to 100% avoid this potential by installing the controller inside my cab.I made room for it behind my glove box. Now it won't matter what's going on outside - this controller will not be affected by it. This should help it last for the life of the vehicle, or the life of the components inside the controller at-least.To further help keep the controller itself and all wires working long term I used heat-shrink fittings and heat-shrink tube everywhere. The wires that comes with the controller are quite good. 4 heavy 10AWG are permanently attached for the primary power, while smaller gauge wire is provided for the rest.The lengths of the wires included are sufficient for those planning under-hood installations. I purchased additional wire, including color coded 10AWG from local shop to make sure I had plenty to reach my inside target.I also added an indicator light inside for the fan. It's a variable voltage LED fed by tapping into the positive and negative fan power leads off the controller. It works perfectly, including showing the variable voltage of the controller via its dim level.This specific method of tapping into the fan power leads to feed the light is a direct response to me asking Flex-a-lite engineer the method they recommend to add such a light to their controller.Below is part of the response I got from Flex-a-lite staff on my question:Direct Quote: "Anyway, we do not have a diagram or write up on how to install an indicator light on the VSC, but I can give you a brief explanation on how it can be done. Basically, there is no way to wire 2 lights, so you will have to go with your second option. You will use an LED and wire it as follows. The positive side of your LED will tap into the yellow wire at position 3 on the VSC. The negative side of your LED will tap into the purple wire at position 2 on the VSC."It works very well and is safe to do assuming the light is a proper 12v automotive or other appropriate light.The temperature adjustment pot of the controller is the least enjoyable aspect of the controller design. It's a very simple, limited component without any proper notations. This leaves you blind to guess and experiment to dial in whatever temperature you're aiming for.To eliminate this problem I used a combination of an ODB2 scanner monitoring the engine coolant and the LED. With these I was able to precisely get the fan doing what I wanted, when I wanted it.The OBD2 scanner can be found here:OBD2 Scanner, Seekone Professional Car Auto Diagnostic Code Reader OBDII & CAN Vehicle Engine O2 Sensor Systems EOBD Scanners Tool for all OBDII Protocol Cars Since 1996(Upgraded SR860)In the end my cooling is working fantastic and this controller is a key reason. I've used cheaper fans and controller. They're far less potent, lack soft start and variable. This controller is worth it from what I've experienced so far.

### ⭐⭐⭐⭐⭐ Great for an LS swap.
*by C***. on October 15, 2024*

I used this controller for an LS swap e fan conversion. Works great with the factory e fans in 03-06 trucks/ suvs. Wiring was straight forward and easy to understand. Tool less than one hour to complete the job. One thing that could change is the length of wire coming out of the controller. It’s pretty short and looks tacky when you have a controller with but splices immediately headed towards the fans or battery. Other than that I have used them on LS swaps, e fan conversions, duramax fan swaps. Great product and not cheaply made like the Chinese versions.

### ⭐⭐⭐⭐⭐ better unit that before
*by J***L on May 30, 2010*

This is a nice unit. Its a little pricey but it doesn't look like the other style with just the adjustable knob. I couldn't live with that ugly thing in my engine bay.I had the unit before this one. The unit I had before had connectors all over it and everything plugged into it. What happened was that the connectors went bad and pulled out. I was able to fix it but I ended up buying another one. Also It comes with the beefy fuse. The old style, the fuse was small and I went through like 4 different fuse holders and fuses because it kept melting. Good call FINALLY.The new one for the main power has wire leads coming out of the unit, which is better because It cant break like the old one. I love the fact that this unit Powers at 60% then at 100% when the temperature goes up. It doesn't put much of a load on the engine either.This unit is for the type of person who wants a clean looking engine bay, clean wiring, and effectiveness. Its only a little bit more than the model before it, but it looks SO MUCH BETTER!

## Frequently Bought Together

- Flex-A-Lite Variable Speed Control Module with Stainless Steel Temperature Probe (31165 / 123241)
- Fan Mounting Kit, Mellbree 2-Pack Electric Radiator Fan Mounting Kit Compatible for Electric Cooling Fan and Transmission Cooler
- Flex-A-Lite Flex-Wave Reversible Electric Fan, 16 inches (236/116544)

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*Product available on Desertcart South Africa*
*Store origin: ZA*
*Last updated: 2026-02-25*