OTC 6589 Electronic Ignition Spark Tester

Professional Mechanic here, May 7, 2013
I own an automotive repair facility that employs 3 other technicians and I have been using spark testers for over 30 years and I have tried them all:
1. The plastic encapsulated ones (not reliable or accurate)
2. The "In Line" type - NEVER - NEVER USE THESE!!
It only takes around 10,000 volts to "light" those up - but todays cars need upwards of 50,000 volts so you'll have a "light" but not enough volts to fire the spark plug.
3. I have had 2 OTC 6589's in my box for 20 years - they ALWAYS work AND tell the TRUTH!
Yes, I have played around with the others and ALL OF THE DIFFERENT STYLES OF THE FIRST 2 I LISTED HAVE CAUSED ME TO MISS A DIAGNOSTIC. (Hence - cost me productivity time & money)
But, when I am in doubt, I grab my OTC and PROVE IT!
When I am diagnosing a V-6, V-8 or V-10 motor, I use 2 of these at the same time - one on each side of the motor.
Sadly, I dropped one and it being porcelain - it broke (just like a regular spark plug would)
So I just ordered 2 more today to keep in my shop.
By the way--- the KD 2757 that "LOOKS" the same as the OTC one DOES NOT!!! They changed the design and it is now "plastic encapsulated" and not as accurate. (Same design as the KD 2756)
Yes - the OTC is more expensive but this is truly a case of " YOU GET WHAT YOU PAY FOR!"

Esay to use tester, March 12, 2013
Just plug in to your spark plug boot to test for a bad distributor cap or bad coil pack for newer cars. Will also test the high tension wire or you can use a piece of vacuum tubing to directly test the coil! This tool makes it easy to troubleshoot your no spark problem. Get a remote starter to make it a one person task. Also don't forget a jumper cable because most likely your spark plug wire wont reach a spot to ground the clamp on.

I docked 1 star because the ceramic spins inside the the metal ring that has the grounding clamp. So far this hasn't seemed to stop it from working but I would have liked it to be solid.

Does its job, March 23, 2014
I have only used it for one job so far, but it works as advertised. The spark is very easy to see and hear even in the sunlight. The part seems very well built and should last awhile. One tip, instead of using the built in clip to ground the Spark Tester, clip a battery jumper cable onto the Spark Tester clip and then ground the battery jumper cable. It gives you a lot more room to work with.

Great tester, January 2, 2014
Top of the line tester for the money. All my friends are in line to use it.
Found the miss I was looking for.

easy to use, November 2, 2013
easy to use and works great. Just unplug a spark plug wire, snap onto tester, and clip tester to metal to ground it. Crank engine and watch it spark (or not).

great spark tester, October 26, 2013
it works like its suppose to and gets the job done.
This tester seems much higher quality then the ones ive seen in auto part stores and with this particular model you definitely cant complain with the price

Spark tester, September 25, 2013
I got this quick in the mail.this is useful I use them in the shop.for the price is good.ill recommend this for any one that works in a shop.

Worked great. Very easy to use., July 16, 2013
Worked great on my HEI system. Much better than the cheapy one I had before. Very easy to use. Should be in everyone's tool box. Can't beat the price either.

great tester, May 17, 2013
you get a spark tester exactly how it shows it in the picture. works great haven't had a problem with it yet.

Worked well for me, May 4, 2013
I have a high mileage 2006 Honda Odyssey EX-L. Used this to test the coil packs and wiring to keep my Ody purring like a kitten. This is the first time I’ve used a tool such as this. There may be better tools out there, but this one did the job for me. Easy to use and worked great. Seems sturdy to me, however this is not a tool I will use frequently.