How is that wrong lol, when removing a fuse that goes to a short your relieving it of some current draw therefore making the light brighter. When you turn on the headlamps your increasing the current draw, therefore it will dim.

Im no idiot, Im certified in Electronics technology as well as many other C-Tech certifications.

 

OK if you have an electronics background I can speak technically. Perhaps I'm not expressing myself properly, but with your background I'm sure you'll understand.

This theory involves placing the lamp in series between the - battery cable and the - battery terminal. The lamp is completing the circuit and is acting as a resistor. The lower the resistance (a more direct path to ground) of the circuit equates to more voltage dropped across the series resistor (in this scenario the lamp). The more voltage dropped across the resistor (lamp) the brighter it glows. Does that make sense or am I still not saying it correctly?

 

Opposite, the lower resistance=less voltage drop. Higher resistance=more voltage drop. And the light(analogical resistor) would not "change" its rating just due to a higher draw post resistor. It would have to be after the location of the short. Resistors are not variable, unless specified such as a potentiometer. A light bulb would act as a set impedance though.

 

But technically now we're talking about 2 resistors in series. The lamp being the first and the vehicles electrical system being the second. Right?

 

In a sense, but then the whole thing is a resistor, even the wiring.

But if you want to think of it like that, I guess you can being the impedance would be greater on those two specific parts.

 

That's the whole theory. Looking at the electrical system as one varying resistor (the variation being the sum of all the individual resistances) and the fixed resistance of the lamp. As the resistance of the system changes by unplugging fuses, more voltage will be dropped across the fixed resistor, thus the varying brightness.

 

I try the bulb test and I put back everything back.
The glows very little but it does glow, if i remove the fuse from the iod socket the light turns off. It comes back on when I put back the fuse. When I disconnect my radio the bulb goes out and the amp meter drops to zero. With fuse removed I have no draw as far as I can tell.

 

I try the bulb test and I put back everything back.
The glows very little but it does glow, if i remove the fuse from the iod socket the light turns off. It comes back on when I put back the fuse. When I disconnect my radio the bulb goes out and the amp meter drops to zero. With fuse removed I have no draw as far as I can tell.

 

What type of lamp were you using? Is it an automotive lamp? Is it like the dome light, or the backup light, or ......something else? Just curious

 

Test light.
The one you use to check for power

 

Really? Wow!!!!

If what you have going on in your truck made the lamp glow just a little, that's pretty good. That's a tiny lamp. Now i'm really curious.

How about you leave the lamp in place and start moving things around. bang the dash and all the interior panels a little, shake some harness's a bit (even under the truck), just see if there's something that might not be apparent. If you get the light to glow bright, you got it. Just a thought.

 

I pressed the brakes open & close doors and the light does get brighter.
I unhooked the radio & the light went out. when I pulgged it back in the light came back on. still the draw is onlt .25 or .26. nothing else has changed.
I think in going to leave the fuse out & see if the battery loses power.
I dont see anything.

 

That's cool you tried some of the switches. At least you know they're not in a 1/2 state and are turning off all the way. A 1/4 amp of total draw isn't that much so I can't see it draining a battery too quickly. Do you have keyless entry? What's the light do after you lock the doors? I think you need to keep looking if you're sure the battery is being drawn down. I also think you can abandon the meter and just use the bulb. If you put it on long clip leads you can move it so you can see it from anywhere while you're moving things.

 

charge the battery and disconnect it in the morning hook it back up if it starts the bat good

 

is the under hood light stuck on if you have one check the glove box light