



🔧 Test smarter, not harder — the pro’s choice for flawless circuit diagnostics!
The OTC 3633 Mini-Coil Cord Circuit Tester is a professional-grade electrical testing tool designed for pinpointing shorts, grounds, and open circuits in 6V and 12V systems. Featuring a needlepoint stainless steel probe, a bright red replaceable bulb, and a 12-foot heavy-duty coiled cord, it combines precision, reach, and durability in an ergonomic design trusted by automotive technicians worldwide.





| ASIN | B003YNHVQQ |
| Best Sellers Rank | #156,730 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #243 in Circuit Testers |
| Brand | OTC |
| Color | Red |
| Customer Reviews | 4.6 4.6 out of 5 stars (980) |
| Date First Available | November 28, 2008 |
| Global Trade Identification Number | 00731413505751 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 0.035 ounces |
| Item dimensions L x W x H | 2.85 x 8.55 x 1.7 inches |
| Item model number | 3633 |
| Manufacturer | OTC |
| Manufacturer Part Number | 3633 |
| Measurement Type | Voltmeter |
| Min. Operating Voltage | 6 Volts |
| OEM Part Number | 3633 |
| Power Source | Corded Electric |
| Product Dimensions | 2.85 x 8.55 x 1.7 inches |
| Style | Modern |
| UPC | 731413505751 521375009516 071020055936 031112405384 523161139902 012302908908 999992883251 |
| Voltage | 12 Volts |
M**N
High quality made very well
Really good product as usual OTC brand high quality is easy to use anywhere in the car fuse box under the hood or under steering wheel, wire terminals even if they are tiny i used one of the teammate working in the shop .i do receive the one purchased from amazon in the weekend i just make test on 9v battery .
A**A
Good quality
I was thinking about getting a snap on one until I seen this, comes with another alligator clip,it being so small makes it feel better in your hand and easy to get into tighter areas. The tip being so pointed and small makes it’s easy to pierce wiring without breaking wire or putting a big whole
J**L
Great test light
Very well built test light and does exactly what it's supposed to! Love the compact size and bright incandescent bulb. Needle tip has a threaded end and comes with an alligator clip.
M**C
ONE OF THE BEST TEST LIGHTS AVAIABLE
This design of test light is nearly perfect, and is an amazing value. The quality of the light and cable are really good, and it feels great in your hand. It is able to easily maneuver into tight spots and has become one of my favorite/most used test lights. The provided light bulb is adequate for most uses, but can also be easily replaced with various other options for custom current requirements. I guess OTC has recently discontinued this light???? IF SO I BEG THEM TO RESUME MAKING THEM!
T**A
Great test light
Best test light imo. Doesn't get better than this
J**S
Good
Nice
J**R
Works great. Cord is a little stiff and it's hard ...
Works great. Cord is a little stiff and it's hard to open clamp unless you slide the boot back.
L**N
Very good
Very good 👍
T**Y
I love this test light, especially in tight confines and in this day and age of led everything an incandescent bulb is very handy.
I**L
المشكله في الاسعار غير ثابته وترتفع
B**T
This is my second OTC test light. I was so impressed with the quality of my normal size version that I came back to purchase this mini version as well and I am glad I did. Overall the OTC test lights are the nicest I've seen. The quality is much nicer than even my snap-on circuit tester which I purchased after my two OTC test lights. The snap-on costs roughly 5 times the price, and although it has the ability to be used as a normal test light with a ground/power indication, as well as a voltage tester, the overall quality is nowhere near as nice. I have barely used the snap-on and find myself reaching for the OTC nearly every time. It's hard to explain what makes them so nice, but as soon as you take it out of the box I'm sure you'll be impressed. The clamp, chord, plastic body, logo printing, light brightness, probe tip are all excellent. The brilliant part about the mini OTC is it's usefulness on more modern cars with fuse boxes in the glove box or any other tight space. It is considerably smaller than the normal version and is much more maneuverable in tight spaces.
M**T
This is a professional quality test light suitable for testing 12v vehicle electrical systems. Well built, solid feel. The main alligator clip connector is surrounded by an insulating sleeve, pull that back, clip on, replace the insulator. Spare bulbs available. Does the job, what more do you need.
D**N
A superb test light in all senses! The best on market.
Trustpilot
1 week ago
3 weeks ago