




⚡ Never miss a spark—ignite your diagnostics with precision and confidence!
The Calterm 66331 Tru-Spark Ignition Firing LED Indicator is a compact, battery-powered tool featuring an exclusive adjustable sensitivity dial to isolate plug wires and prevent false signals. Equipped with green and red LEDs for clear operational and ignition feedback, it boasts a rugged ABS housing designed to resist oil and endure tough shop conditions. Compatible with both DIS and conventional ignition systems, this precision tester is engineered for professional-grade ignition diagnostics.
| Brand | Calterm |
| Power Source | Battery Powered |
| Style | Adjustable |
| Color | Green,Red |
| Item dimensions L x W x H | 2.2 x 5.9 x 1.4 inches |
| Specification Met | CE, ETL, RoHS, UL |
| Measurement Type | Voltage |
| UPC | 971473127474 046494020230 521227771189 956257381846 |
| Manufacturer | Calterm |
| Global Trade Identification Number | 00046494020230 |
| Model | 66331 |
| Item Weight | 0.634 ounces |
| Product Dimensions | 2.2 x 5.9 x 1.4 inches |
| Item model number | 66331 |
| Is Discontinued By Manufacturer | No |
| Manufacturer Part Number | 66331 |
H**D
Works great
Great tool
S**5
Quick and Reliable Spark Plugs, Cables and Ignition Tester
Quick and reliable Spark Plugs, Cables and Ignition Tester. We use these daily to verify spark plugs, cables and ignition fault codes from OBDII scanner before inspection and removing from engine. Easy to use and good value. Sensitivity dial is a little loose so it is important to test and experiment with different settings for domestic and import cars.
S**E
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.
S**I
Complete waste of time
I don't know where these reviews come from but I'm sorry I believed them. The LED's work as advertised but this doesn't detect ANY coil pulses at all. I tried this on my 2003 Honda motorcycle and then on my 2001 Camaro. You press the clip and the green LED stays on but no red pulsing. Complete waste of my time and money.
G**C
good to determine spark/no spark in the sun
I purchased this because I needed a spark tester that I could see in bright sunlight. It does this well.The only issue I have is that I don't get a good feel for how strong the spark is. It has a sensitivity adjustment but that doesn't really help if my spec says that the spark must jump 3/8 inches. For this I need a tester that I can see the actual spark, which means do it in the shade.
A**R
Amazing
Unique technology very useful.
A**N
Works great, just flimsy.
I'm here to buy a second one of these. I love the tool but it is just too delicate. On my first one the body separated and it got a loose connection on the circuit board. I'm going to super glue my next one at the seams. Also be careful not to lay it down on the clip or you'll drain the batteries. It really should include a protective case as it is more delicate than calipers. I haven't found any comparable tool. It's an awesome tool, just be sure to handle with CARE and have extra backup batteries. Works good in full sun, led is still visible.
B**L
Would buy again!
Had a dead coil on #1 cylinder 2014 silverado. This tool did exactly what it was designed to do and showed me which coil was dead. I only used it thisnkne time so far, but I'd buy it again! Pro tip, take the button cell batteries out when not in use that way when they go bad they won't destroy the internal electrical terminals.
A**R
Work very good
D**S
Very handy tool. Accurate. Just remember that this is a firing tool, if your engine is not capable of firing ie. Too much fuel. It will not show you the energy coming from the coil.
T**S
hard to say how much spark , because you can adjust the sensitivity , only used once . Would be nice if you could turn on , and clip on ignition wire , short handed , if you are testing a pull start item
G**R
A good diagnostic tool when it comes in testing sparks and spark strength by adjusting the dial knob sensitivity. It’s made of plastic, just put extra careful when using or storing it.
N**P
Cheap quality
Trustpilot
1 month ago
5 days ago