Fuse Tester Pens: 3 Picks Compared
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This comparison covers three fuse-checking test pens from the research file for a fuse tester pen search. The file holds four listings. The Klein NCVT1P voltage pen is left out because its listing describes a non-contact voltage tester with no fuse or circuit-test function. Every figure below comes from a listing as the seller states it and is dated 11 October 2026.
Quick answer: for a 12 V car circuit, all three pens cover the voltage. For a 24 V truck or a 36 V to 48 V system, only the WINAMOO and JASTIND ranges reach that high. Check the voltage range and the probe reach against the circuit you are testing, then pick the pen with the readout you need.
The three pens at a glance
| Pen | Listed voltage range | Readout (as listed) | Best fit |
|---|---|---|---|
| WINAMOO Test Pen (B0D8PXNPYH) | 3 to 48 V | LED digital, 0.1 V resolution | Cars, trucks and SUVs up to 48 V |
| JASTIND Test Pen (B0F5WK8TJY) | 3 to 48 V | LED digital readout | Cars, motorcycles, trucks and boats |
| FEAOXYO Test Light (B0DX5GMXYH) | 6 to 24 V DC | Bulb, no digital readout stated | Cars, SUVs, RVs and trucks at 12 V or 24 V |
How we chose these three
We kept listings whose title or bullets describe a pen or test light that checks a vehicle fuse or circuit. Each listing was then read for voltage range, readout, probe and cord reach, and included accessories. A figure the listing does not state is reported as not stated. We did not test any pen in person, and nothing below reports use on a real vehicle.
- Fit: the voltage range and the vehicles the listing names.
- Parts: the cord length, probe, clip and anything else the listing says is in the box.
- Readout: a digital figure or a light only.
1. WINAMOO Automotive Test Light with Digital Readout
The WINAMOO pen is listed for 3 to 48 V systems, with an LED digital display that shows voltage to 0.1 V. The listing says it can test car battery voltage and alternator charging on cars, trucks, SUVs and boats. Its probe is a sharp stainless steel tip for piercing insulation, with a protective sleeve for storage. The spring cord is listed at 96 inches, which is 8 feet of reach. The listing describes a shatter-proof ABS body and a large alligator clip for one-handed use. It is listed as corded electric and measures 11.1 by 4.2 by 1.4 inches. Checked 11 October 2026.
2. JASTIND Automotive Test Light with Voltmeter
The JASTIND pen is listed for 3 to 48 V with an LED digital readout and a polarity indicator. Its listing names cars, motorcycles, trucks and boats as compatible vehicles. The probe is stainless steel, the clip is large, and the cord is listed at 96 inches. A protective sleeve covers the probe in storage. The handle is described as shatterproof and shockproof, and the listing says it tests in both directions. The package in the listing contains only the 3 to 48 V test light, with no spare probe or extra leads named. The listing gives no size or weight and no power source. Checked 11 October 2026.
3. FEAOXYO Automotive Circuit Tester Test Light
The FEAOXYO pen is listed for a 6 to 24 V DC range. It is a test light with a bulb rather than a digital readout, and its bullets say the bulb brightness changes with the measured voltage. The listing describes a large alligator clip for one terminal and a long steel probe, with a 39 inch PU wire that it calls flexible and lightweight. It says the pen can find short circuits and faulty fuses by connecting the clip and probing the other side of the circuit. The listing names sedans, SUVs, RVs and trucks. Its power field reads battery powered, but the bullets describe a bulb that lights from the circuit. That conflict is shown here rather than resolved. Checked 11 October 2026.
Worked example: does a 12 V and a 24 V system fit each range?
For example, take a 12 V car battery circuit. All three ranges include 12 V. Now take a 24 V truck circuit. The WINAMOO and JASTIND ranges run from 3 to 48 V, so 24 V sits well inside them. The FEAOXYO range stops at 24 V, so a 24 V reading is at the very top of its listed span and any higher system falls outside it.
Reach is the second check. A 96 inch cord gives 8 feet (96 divided by 12) on the WINAMOO and JASTIND pens. The FEAOXYO’s 39 inch wire gives about 3.25 feet (39 divided by 12), which is less than half the reach. The WINAMOO’s 0.1 V resolution shows a 12.6 V reading and a 12.0 V reading as 6 steps apart, which is a finer result than a 0.5 V step would give.
What the listings do not say
None of the three listings gives a test of how well the pen finds a bad fuse, and none names a fuse rating. The listings do not say whether the probe can be swapped if it wears or breaks. Two of the three list a digital readout, while the FEAOXYO shows a bulb only, so a reader who needs a number on the pen should choose the WINAMOO or the JASTIND.
Frequently asked questions
Can these pens check a fuse without removing it?
The FEAOXYO listing says its probe can detect short circuits and faulty fuses when the clip is on one side of the circuit. The JASTIND listing calls its pen a fuse tester, and the WINAMOO listing describes voltage and circuit testing. None of the listings explains how to test a fuse in place, so follow the instructions before you use one on a fuse.
Which pen covers a 24 V truck circuit?
The WINAMOO and JASTIND pens list a 3 to 48 V range, so 24 V is well inside it. The FEAOXYO lists 6 to 24 V DC, so 24 V is at the very top of its range.
Which pen shows a digital number?
The WINAMOO and JASTIND pens both list an LED digital readout. The FEAOXYO listing describes a bulb that gets brighter with voltage and does not name a digital display.
How long is the cord on these pens?
The WINAMOO and JASTIND listings give a 96 inch spring wire, which is 8 feet of reach. The FEAOXYO listing gives a 39 inch PU wire, which is about 3.25 feet. The listing figures do not say how the cords hold up over time.
Why is the Klein NCVT1P not in this comparison?
Its listing describes a non-contact voltage pen for 50 to 1000 V AC and gives no fuse or circuit-test function. It is a different tool, so it is left out of this fuse comparison.
Conclusion
For a digital reading on a car or truck circuit, the WINAMOO and JASTIND pens are the two picks. Both list 3 to 48 V and a 96 inch cord. The FEAOXYO is a bulb-style test light for 6 to 24 V, a sensible choice when a light is enough. Check the voltage range and the cord reach against the circuit before you buy.
For more on testing a car circuit, see best wire tester for car, best auto voltage tester, and best continuity tester.
