Car constantly pulling power with key off?

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Justin Angle

Justin Angle

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Hey guys I'm finishing up my slant to 360 swap on my Duster and I noticed went putting the positive terminal on it kind sparks like something is pulling power...even with the key off. The car has an MSD 6al box if that makes any difference. I noticed today when I was hooking up the fuel pump relay I even had the positive cable totally off and accidentally bumped 2 wires and it sparked a little bit. Is this normal? What could be constantly pulling power? Thanks
 
Start unhooking things until the draw stops. There shouldn't be a draw unless you have a clock or radio memory. And then only miliamps.
 
remove the negative cable put a test light between the cable and terminal if the light comes on you have a short -- start pulling fuses
 
dodge71demon said:
remove the negative cable put a test light between the cable and terminal if the light comes on you have a short -- start pulling fuses
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So I unplugged the negative terminal and ran a test light from the terminal to the negative cable and the test light cam on. I pulled all the fuses and the test light still comes on and still sparks a little when I go to contact the positive terminal.
 
Got it figured out. I have the master cylinder out and the brake pedal tied to the steering wheel but it was tied up loose so still was engaging the brake lights. (Brake lights are out so I couldn't tell) thanks for the help
 
If brake lights are out there should not be a load
 
Maybe the hazard switch is on? Bear in mind there ARE THINGS that can leak and are not fused. One example is the alternator.......unhook the main charge wire. Examine the car for aftermarket stuff added. How about one of those big aftermarket stereo amps? They are normally hooked up "power hot" similar to an MSD and with a trigger wire. The PA transistors can leak. How about dome/ or trunk/ glove box lamp?

The suggestion with the test lamp IS VERY GOOD and a test lamp should always be used BEFORE an ammeter/ milliameter is connected, because a big, high current short can damage some meters............or at least blow an expensive meter fuse. The special fuses in the Fluke meters are damn near 10 bucks each
 
67Dart273 said:
How about dome/ or trunk/ glove box lamp?
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That's why I asked if the doors were open I spent an hour trying to find a leak, I had a good laugh at myself when I shut the door! DUHHHHH!

I'm assuming it is a later year car and some had seat belt warning or other warning things, I dont know how they interact.

BUT OP says it was the brake switch so I guess the case is closed!
 
FWIW, here is something I have seen: If your car has a glove box light, it is entirely possible that the switch has gone bad, and the light is on all the time. Open the glove box and touch the bulb, if it is hot right away, it has probably actually been on for a while. A small bulb like that does not get hot in the two seconds it will take to reach your hand in and touch the bulb.
 
Yeah after tying up the brake pedal better its no longer pulling any power. But the brake switch is kind of finicky. Sometimes it works and sometimes it dosent. So that needs to be added to the list
 
OK but you said the lamps are out. If there are no rear lamps the brake switch should not cause a draw.
 
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