---
product_id: 7531859
title: "Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red"
brand: "calterm"
price: "₹ 3659"
currency: INR
in_stock: true
reviews_count: 13
category: "Calterm"
url: https://www.desertcart.in/products/7531859-calterm-66331-tru-spark-ignition-firing-led-indicator-adjustable-sensitivity
store_origin: IN
region: India
---

# Adjustable sensitivity dial Rugged ABS housing for durability Dual LED firing & power indicators Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red

**Brand:** calterm
**Price:** ₹ 3659
**Availability:** ✅ In Stock

## Summary

> ⚡ Never miss a spark—ignite your diagnostics with Tru-Spark precision!

## Quick Answers

- **What is this?** Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red by calterm
- **How much does it cost?** ₹ 3659 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.in](https://www.desertcart.in/products/7531859-calterm-66331-tru-spark-ignition-firing-led-indicator-adjustable-sensitivity)

## 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:** High-impact ABS casing resists oil and withstands tough shop environments—your reliable work companion.
- • **Instant Visual Feedback:** Green LED confirms power; red LED pulses with each spark, so you never miss a firing event.
- • **Universal Compatibility:** Seamlessly tests both DIS and conventional ignition systems, making it a versatile must-have tool.
- • **Pocket-Ready Convenience:** Compact design with clip-on activation keeps it handy and ready for on-the-go troubleshooting.
- • **Precision Sensitivity Control:** Exclusive dial isolates specific plug wires, eliminating false signals for pinpoint diagnostics.

## Overview

The Calterm 66331 Tru-Spark Ignition Firing LED Indicator is a compact, battery-powered tester designed for quick, accurate detection of secondary voltage in DIS and conventional ignition systems. Featuring an exclusive adjustable sensitivity dial, dual green/red LEDs for power and spark indication, and a rugged ABS housing, it ensures reliable performance in demanding automotive and powersports environments. Ideal for professionals and DIYers alike, it helps prevent costly service calls by enabling precise ignition troubleshooting.

## Description

Testing equipment can be put to good use ensuring that electrical equipment is properly installed and safe to operate. Faulty installations can be lethal; the condition of electrical installations can be established when contractors use test equipment. Calterm is please to offer an innovative full feature line of test equipment designed to make electrical work faster and safer. Quickly and accurately test DIS and other ignition systems for the presence of secondary voltage without piercing or removing spark plug wires. Great for troubleshooting 'no-starts'.

Review: Easy to use. - This is the second one of these that I've had. I should have never let a co-worker borrow the first one. He quit and I never got it back. It's a nice little unit for testing to see if you have a plug that's firing like it should. It has a a clip so can stick it in your pocket. A thumb wheel that you can turn the sensitivity setting up or down with. The pocket clip acts as an on switch. Just hold it down and the green light comes on. Put it next to a plug wire or a coil tower or a spark plug boot. And if getting spark. The green light will pulse red every time it fires. The top part of the pocket clip hold in the three coin batteries that makes it work. The first one I had the batteries lasted for a long time. (several years) Fairly rugged. Had mine fall out of my pocket onto a concrete floor many times and it never effected the way it worked. Handy device that I feel is well worth the money.
Review: Great product - Saved me a very high priced remote service call for problems with my boat engines. I was haveing problems on one of my engines, it was running rough and would not go above 3000 RPMs, With the help of my boat yard mechanic (B&E in Michigan City Indian AWESOME team) on the phone I checked the plug wires with the above tool to find out that one engine was not firing on 2 of the 8 cylinders, through additional trouble shooting we replaced the plugs and all 8 are firing. This $19 dollar tools and $12 for 2 spark plugs and i am running smooth again. A remote service call would have cost at least $300. This tester is easy to use and calibrate even if I only use it ounce, which I wont, it was more then worth it.

## 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 |
|---------------|-------|
| ASIN | B000JFHMPC |
| Best Sellers Rank | #136,544 in Automotive ( See Top 100 in Automotive ) #103 in Powersports Ignition Coils |
| Brand | Calterm |
| Brand Name | Calterm |
| Color | Green,Red |
| Compatible Devices | Vehicles with DIS or conventional ignition systems |
| Customer Reviews | 4.2 out of 5 stars 369 Reviews |
| Global Trade Identification Number | 00046494020230 |
| Item Dimensions | 2.2 x 5.9 x 1.4 inches |
| Item Type Name | LED Indicator |
| Item dimensions L x W x H | 2.2 x 5.9 x 1.4 inches |
| Manufacturer | Calterm |
| Measurement Type | Voltage |
| Model | 66331 |
| Number of Items | 1 |
| Part Number | 66331 |
| Power Source | Battery Powered |
| Specification Met | CE, ETL, RoHS, UL |
| Style | Adjustable |
| Style Name | Adjustable |
| UPC | 971473127474 046494020230 521227771189 956257381846 |
| Unit Count | 1 Count |

## Product Details

- **Brand:** Calterm
- **Color:** Green,Red
- **Item dimensions L x W x H:** 2.2 x 5.9 x 1.4 inches
- **Power Source:** Battery Powered
- **Style:** Adjustable

## Images

![Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red - Image 1](https://m.media-amazon.com/images/I/71R5oKpSNAL.jpg)
![Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red - Image 2](https://m.media-amazon.com/images/I/71e2wcEolPL.jpg)
![Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red - Image 3](https://m.media-amazon.com/images/I/71JaUL5uNJL.jpg)
![Calterm 66331 Tru-Spark Ignition Firing LED Indicator, Adjustable Sensitivity, Green,Red - Image 4](https://m.media-amazon.com/images/I/819anuVXdGL.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.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Easy to use.
*by S***E on May 20, 2024*

This is the second one of these that I've had. I should have never let a co-worker borrow the first one. He quit and I never got it back. It's a nice little unit for testing to see if you have a plug that's firing like it should. It has a a clip so can stick it in your pocket. A thumb wheel that you can turn the sensitivity setting up or down with. The pocket clip acts as an on switch. Just hold it down and the green light comes on. Put it next to a plug wire or a coil tower or a spark plug boot. And if getting spark. The green light will pulse red every time it fires. The top part of the pocket clip hold in the three coin batteries that makes it work. The first one I had the batteries lasted for a long time. (several years) Fairly rugged. Had mine fall out of my pocket onto a concrete floor many times and it never effected the way it worked. Handy device that I feel is well worth the money.

### ⭐⭐⭐⭐⭐ Great product
*by C***R on May 29, 2014*

Saved me a very high priced remote service call for problems with my boat engines. I was haveing problems on one of my engines, it was running rough and would not go above 3000 RPMs, With the help of my boat yard mechanic (B&E in Michigan City Indian AWESOME team) on the phone I checked the plug wires with the above tool to find out that one engine was not firing on 2 of the 8 cylinders, through additional trouble shooting we replaced the plugs and all 8 are firing. This $19 dollar tools and $12 for 2 spark plugs and i am running smooth again. A remote service call would have cost at least $300. This tester is easy to use and calibrate even if I only use it ounce, which I wont, it was more then worth it.

### ⭐⭐⭐⭐⭐ Works great
*by H***D on December 6, 2025*

Great tool

## Frequently Bought Together

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*Product available on Desertcart India*
*Store origin: IN*
*Last updated: 2026-09-15*