Finding a short
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Get a 12V test light. Disconnect negative battery cable. Hook test light the negative cable and the negative post of the battery where you removed the cable. If there's a short present, the test light will light up.
Be sure everything electrical is shut off. Doors closed so dome light is off, etc.
Pulling one fuse at a time, check to see if light goes out. You can sometimes isolate the problem circuit like this.
First things to check would be alternator, regulator by unplugging them.
Be sure everything electrical is shut off. Doors closed so dome light is off, etc.
Pulling one fuse at a time, check to see if light goes out. You can sometimes isolate the problem circuit like this.
First things to check would be alternator, regulator by unplugging them.
>>Hook test light the negative cable and the negative post of the battery where you removed the cable. If there's a short present, the test light will light up.
I am a little unclear here. If I hook up the test light to both the neg cable which is unplugged and the negitive post, wont I essentially be reconnecting the two?
I am a little unclear here. If I hook up the test light to both the neg cable which is unplugged and the negitive post, wont I essentially be reconnecting the two?
Yes and that is what you want. With everything off, including dome light, clock, the lite SHOULD not come on.
If it does come on, start isolating circuits as OL explained. With this method you are looking to isolate the bad circuit which is causing the test lite to come on.
If it does come on, start isolating circuits as OL explained. With this method you are looking to isolate the bad circuit which is causing the test lite to come on.
I ran the test and the light did NOT go on. I belive this means there is no short?
To make sure I understand the method of this test, if the light would have come on, would this mean that at some point in the car a positive wire was touching a negative wire or ground, causing the test light to come on?
Thanks for the lesson.
To make sure I understand the method of this test, if the light would have come on, would this mean that at some point in the car a positive wire was touching a negative wire or ground, causing the test light to come on?
Thanks for the lesson.
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213 Posts
CharlieD, the test light method does work but it requires you or someone else to constantly watch the light. If you wiggle wires and switches and connections the short will make the test light go off and on intermittently when you are wiggling the shorted wire or contact.
I use a little 12 volt buzzer. Hook it up just as you would the test light or in place of the fuse that keeps blowing. The buzzer will buzz as long as there's a short. If you wiggle the shorted wire or switch or whatever, the buzzer goes on and off telling you that you found the general area or particular wire that is shorted.
The best part is that you don't have to look at it to find the short. When the buzzer stops buzzing, you've found it.
I always look for the lazier way to do it.
Louie Hammel
I use a little 12 volt buzzer. Hook it up just as you would the test light or in place of the fuse that keeps blowing. The buzzer will buzz as long as there's a short. If you wiggle the shorted wire or switch or whatever, the buzzer goes on and off telling you that you found the general area or particular wire that is shorted.
The best part is that you don't have to look at it to find the short. When the buzzer stops buzzing, you've found it.
I always look for the lazier way to do it.
Louie Hammel
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