---
product_id: 68199103
title: "66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red"
brand: "calterm"
price: "$U2759"
currency: UYU
in_stock: true
url: https://www.desertcart.uy/products/68199103-66331-tru-spark-ignition-firing-led-indicator-adjustable-sensitivity-green
store_origin: UY
region: Uruguay
---

# Dual LED indicators (Green & Red) Adjustable sensitivity dial Rugged ABS housing 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red

**Brand:** calterm
**Price:** $U2759
**Availability:** ✅ In Stock

## Summary

> ⚡ Ignite your diagnostics with precision and confidence!

## Quick Answers

- **What is this?** 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red by calterm
- **How much does it cost?** $U2759 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/68199103-66331-tru-spark-ignition-firing-led-indicator-adjustable-sensitivity-green)

## Best For

- calterm enthusiasts

## Why This Product

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

## Key Features

- • **Built to Endure:** Durable high-impact ABS casing resists oil and withstands tough shop environments.
- • **Lightweight & Compact:** At just 18g and pocket-sized, it’s the perfect on-the-go ignition tester for pros.
- • **Instant Visual Feedback:** Green LED confirms tester readiness; red LED flashes with every ignition spark for real-time monitoring.
- • **Universal Compatibility:** Seamlessly works with both DIS and conventional ignition systems—one tool for every job.
- • **Precision Sensitivity Control:** Exclusive dial isolates specific plug wires, cutting out false signals for flawless diagnostics.

## Overview

The Calterm 66331 Tru-Spark Ignition Firing LED Indicator features an exclusive adjustable sensitivity dial to isolate plug wires and eliminate false signals. Equipped with green and red LEDs for clear operational and ignition feedback, it’s housed in rugged ABS to resist oil and endure harsh shop conditions. Compatible with DIS and conventional ignition systems, this lightweight, compact tester is engineered for professional-grade ignition diagnostics.

## Description

66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red

## Features

- SENSITIVITY ADJUSTMENT DIAL is a Calterm EXCLUSIVE feature that allows isolation of a specific plug wire and eliminates false signals from wires routed in close proximity.
- Green LED indicates that the tester and batteries are operating properly.
- Red LED flashes each time voltage is released from the coil through the spark plug wire.
- Rugged high impact ABS housing resists oil and endures shop conditions.
- Works with DIS and conventional ignition systems.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | Calterm |
| Brand | Calterm |
| Model | 66331 |
| Product Dimensions | 5.59 x 14.99 x 3.56 cm; 18 g |
| Item model number | 66331 |
| Manufacturer part number | 66331 |
| Item Weight | 18 g |

## Product Details

- **Brand:** Calterm
- **Power source:** Battery Powered
- **Style:** Modern
- **Colour:** Green,Red
- **Item dimensions L x W x H:** 5.6 x 15 x 3.6 centimetres

## Images

![66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red - Image 1](https://m.media-amazon.com/images/I/71R5oKpSNAL.jpg)

## Questions & Answers

**Q: Does clamp on?**
A: Hi, no it's not for clamping on, it's for detecting for a spark and so you just touch it on the ht lead

**Q: does it work on small engine 4-cycle, 12V**
A: Our Service  dept use this all the time on small engines.  You do have to properly adjust the dial on the unit for small engines. We use as a quick test.

**Q: does this actually detect if the plug wire is pulled loose from the plug itself?**
A: Probably not, but a good visual inspection should. I use it to narrow down suspect cylinders that have a misfire such as a defective coil or wire. I have also found plugs that arc inside the plug boots.

**Q: Will this work on fuel injectors ?**
A: No- Just  ignitions. Fuel injectors are low voltage.

## Frequently Bought Together

- Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red
- Lisle 19380 Spark Tester
- allsun Automotive Spark Ignition Tester 6-24V Pen Engine Indicator Spark Plug Car Wires Coils Diagnostic Tool Auto Voltage Cable Detector Small Engine Tools

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**Shop now:** [https://www.desertcart.uy/products/68199103-66331-tru-spark-ignition-firing-led-indicator-adjustable-sensitivity-green](https://www.desertcart.uy/products/68199103-66331-tru-spark-ignition-firing-led-indicator-adjustable-sensitivity-green)

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