Topic: Unknown Electrical Drain

[supermat]

Hey guys, its been quite a while since I last checked in! Hope all is well around the boards. I've got a bit of a problem and was hoping you could help me out. I've got an electrical drain that I can't seem to locate, then again, I really don't know where to start. When I leave the truck off I'm all good but as soon as I turn the key to "on" or I start the truck the battery drops very quickly. I checked the alternator and its all good so somewhere I've got a drain that is sucking out juice faster than the alternator can put it back! Ugh, I'm stuck. Help! 

[DTB]

sounds like u have a short somewhere. good luck with that. i would start by checking wires everywhere for any frays or worn sections.... if u dont find it maybe u could rig a battery kill switch..could double as a theft deterrent too

[Shamb]

i'm w/ DTB on this one.. probably have a short in your electircal... just start inspecting all your electrical and grounds.. make sure everythings making good contact and isn't corroded.

good luck.

[Willy Mammoth]

1st. Disconnect the battery and get a test light between the battery cable and the battery post.

If the light lights up you have a draw on the battery.

Make sure the doors are closed and the key is out. Then start pulling fuses one at a time till you find the one the draw is on. The light will not light up unless there is something drawing current through the the bulb.

This will narrow it down to that circut and help you figure it out.

A wiring diagram would be helpfull to see what is on the circut effected.

I would also unplug the alt and disconnect the battery cable to it. There is a chance you have a bad diode causing a drain. If you disconnect the alt and the light goes out you need to replace the alt.

[brainlessfool]

1st. Disconnect the battery and get a test light between the battery cable and the battery post.

If the light lights up you have a draw on the battery.

Make sure the doors are closed and the key is out. Then start pulling fuses one at a time till you find the one the draw is on. The light will not light up unless there is something drawing current through the the bulb.

This will narrow it down to that circut and help you figure it out.

A wiring diagram would be helpfull to see what is on the circut effected.

I would also unplug the alt and disconnect the battery cable to it. There is a chance you have a bad diode causing a drain. If you disconnect the alt and the light goes out you need to replace the alt.

Kinds sounds like your Batt. maybe shot. how old is it. have you let it run into the ground a bunch?

[Tallchevy]

I with W.M. on this. We need to know what your working on? Is it EFI or not. If it is, you will have a small drain due to the ECU has to keep it's memory so you will have a draw but not enough to light a test light. Usually the ECU draws .5 amps or less which isn't enough to cause your battery to drain that fast unless you have a bad cell in your battery. Take your battery to your local parts store & have them load test it. Also, make sure the top of your battery is clean & dry with no corrosion. I have seen batteries drain due to the corrosion/acid build up on top of the battery. It will actually short across the top from positive to the negitive & cause the battery to drain. You can use a baking soda mixed with water & an old tooth brush to clean the connections