Don't Miss

Quick And Easy Test Light Conversion

By Jestine Yong on January 9, 2015

For many years Automotive Technicians have used a test light with an incandescent globe for testing circuits and electrical fault finding such as to locate a defective fuse. You can check out the video below to see how to use a test light to find a bad fuse:

In recent decades, though, more up to date equipment must be used to protect delicate electronic circuits in modern vehicles.

A workmate of mine has always used the old style test light but realized the advantages of a LED test light and asked me if I could convert one of his old test lights.

After finding a base to locate the LED (I used a spare hose cap for this), I removed the globe and fed the wire through the side rather than the existing hole at the top. It is less inclined to get tangled this way.

I used a Bi-Colour Red/Green LED and a 330Ω resistor to suit. After about ½ hour the successful conversion was complete.

At only 20 cents AUD for components compared to $35 dollars AUD for a LED test light, I’d say that the conversion was well worth the effort and my workmate agreed.

Here is the schematic:

You can download the LED information from the link below:

http://pdf1.alldatasheet.com/datasheet-pdf/view/87056/KINGBRIGHT/L483GDT.html

This article was prepared for you by Mark Rabone from Australia.

Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.

P.S- Do you know of any your friends who would benefit from this content that you are reading now? If so, forward this website to your friends or you can invite your friends to subscribe to my newsletter for free in this Link.

Likes

(190)Dislikes

(0)

automobile electronics repair

23 Comments

biruk aweke

January 9, 2015 at 10:14 am

Very nice thanks for sharing.

Likes(3)Dislikes(0)

Reply
- joscamil
  
  January 9, 2015 at 7:23 pm
  
  Dear Mr. Yong , Mr. Rabone,
  
  I fully agree that this tester is a very nice, useful project. What is missing, but, is a small circuit diagram with connections.
  
  With kind regards,
  
  joscamil
  
  Likes(4)Dislikes(0)
  
  Reply
Robert

January 9, 2015 at 10:35 am

Thanks Mark. Nice job.

Likes(1)Dislikes(0)

Reply
Yogesh Panchal

January 9, 2015 at 1:05 pm

Mr.Mark Rabone,

Good experiment!! keep up.

Likes(0)Dislikes(0)

Reply
Ernst

January 9, 2015 at 5:12 pm

Well done Mark. this is some thought to remember. I'm going to build one myself. I have these components lying around and never thought to make one myself.

Likes(0)Dislikes(0)

Reply
Abdul Haleem

January 9, 2015 at 7:38 pm

Hi Mark,
Could you please send us the circuit diagram of this dual polarity tester? Is it the same like the one once Mr. Robert had published??
Thanks

Likes(4)Dislikes(0)

Reply
- Robert
  
  January 10, 2015 at 10:52 pm
  
  Hi Abdul,
  The one that I made uses 2 cheaper LED's - a red & green soldered together because it's cheaper, although I have a bunch of Bi-color(RG) two lead LED's. I have all kinds of LED's including some expensive purple ones. I don't know how Mark get's them so cheap because they are $.50 a piece at www.allelectronics.com unless you buy 1000 or more, then they are $.35 a piece.
  Maybe Mark can give us the website that sells them so cheap?
  
  Likes(0)Dislikes(0)
  
  Reply
  - Mark
    
    January 17, 2015 at 6:43 am
    
    Hey Robert,
    
    Here is a company that I commonly use because of price and availability. Hope it helps
    http://au.rs-online.com/web/p/visible-leds/2471167/
    As you can see the price is 14 cents each in a pack of 5.
    
    Likes(0)Dislikes(0)
    
    Reply
    - Robert Calk
      
      January 18, 2015 at 10:45 pm
      
      Thanks Mark. I'm sure that will help many people. That is a cheap price on those LED's.
      
      Likes(0)Dislikes(0)
      
      Reply
Henrique Ulbrich

January 9, 2015 at 8:18 pm

Very good. Just a a practical experiment.

One thing I could not understand: what is AUD?

Likes(1)Dislikes(0)

Reply
- Robert
  
  January 10, 2015 at 10:56 pm
  
  It stands for Australian currency.
  
  Likes(0)Dislikes(0)
  
  Reply
MAHESH

January 9, 2015 at 10:23 pm

great work Mark.
Could you add what watt capacity LED used.

Likes(0)Dislikes(0)

Reply
Humberto

January 10, 2015 at 12:33 am

Good innovation, congratulations. Healthy and Happy New Year for everybody

Likes(1)Dislikes(0)

Reply
John

January 11, 2015 at 8:24 am

Thanks Mark. AUD is Australian dollar.

Likes(0)Dislikes(0)

Reply
Abdul Haleem

January 11, 2015 at 9:43 am

Hi Henrique Ulbrich,
Let me answer your question for on behalf of Mark. AUD stands for Australian Dollar as Mark is an Australian.

Ragards

Likes(0)Dislikes(0)

Reply
camber

January 11, 2015 at 11:51 am

I really enjoy your Web site!! I thought I had done something wrong
when I could not find a schematic for the fuse test light. When I saw other comments asking the same thing I was relieved it was not just me.

So where can I find the schematic?

camber

Likes(1)Dislikes(0)

Reply
- admin
  
  January 11, 2015 at 5:20 pm
  
  HI Camber,
  
  Mark just gave me the schematic and i have uploaded it.
  
  Jestine
  
  Likes(0)Dislikes(0)
  
  Reply
  - Robert
    
    January 11, 2015 at 6:39 pm
    
    In the USA green means go and red means stop. Does red mean go in Australia?
    
    Likes(0)Dislikes(0)
    
    Reply
    - Mark
      
      January 12, 2015 at 10:00 am
      
      Hey Robert,
      
      As shown on the schematic, Red shows a positive connection and Green shows a negative connection
      
      Likes(0)Dislikes(0)
      
      Reply
G

January 13, 2015 at 12:13 pm

Mark,It's a good job and useful for all of us.
Thank you very much

Likes(1)Dislikes(0)

Reply
Taring

February 12, 2015 at 3:41 pm

Always on the lookout for the cheapest price. Thank you

Likes(0)Dislikes(0)

Reply
Chris

May 24, 2015 at 11:34 pm

Hi! Good job and innovative. But, did you know does this cheap tool is not only a test light for newer cars? 🙂
You can read out whit this tiny LED test light the trouble codes from some older cars and do not have to pay for any diagnostic equipment.
If you thin I can write some article, about how to test cars for stored errors in their memory module and get out the error number whit some tools like this...

Likes(1)Dislikes(0)

Reply
- Gary Gemmell
  
  January 5, 2016 at 5:47 pm
  
  NIce Chris i always look forward to your hacks - you are a true man after my own heart - a true hacker and cracker!
  Keep up the good works!
  
  Hoots from Scotland!!!
  
  Likes(0)Dislikes(0)
  
  Reply