electrical nightmare

[99powerstroke7.3]

Buddy bought a 7.3 few months ago and since he has been fighting an electrical draw. New alternator,2 brand new interstate batteries and after 10hrs its basically dead...cranks but no volts so it wont start. We have noticed with driver door opened the door adjar light doesnt turn on but it will if we open any other door. Any ideas or suggestions on how to approach this one.....I hate electrical work hahaha

 

[cbf9703]

Buddy bought a 7.3 few months ago and since he has been fighting an electrical draw. New alternator,2 brand new interstate batteries and after 10hrs its basically dead...cranks but no volts so it wont start. We have noticed with driver door opened the door adjar light doesnt turn on but it will if we open any other door. Any ideas or suggestions on how to approach this one.....I hate electrical work hahaha

Yeah, electrical sucks. One of my trucks has it's own gremlins. Just to clarify, does opening the driver's door trigger the dome light?

 

[99powerstroke7.3]

Dome lights missing so I couldn't tell ya lol

 

[79jasper]

If it's that big of a draw, you should be able to start pull fuses to see which its drawing from.
I can run my radio for almost that time, and still start it. And my batteries are junk. Lol
Something should be putting off heat. New alt could be bad. See if it's feels warm after sitting.
Sent from my SM-T537R4 using Tapatalk

 

[Vader's Fury]

Disconnect the passenger battery completely. Make sure that all the doors are closed, the key is off, and everything is turned off(lights and such). Unplug anything that is plugged into a 12v source(cigarette plugs).

Then pull the negative terminal on the driver side battery and hook up a test light between the neg terminal on the battery and the cable. If you have a power draw the light will come on.

If the light is on, then pull individual fuses till the light goes out. If you pull a fuse and the light dims then leave that fuse out and keep going until the light is out. Then once you get the light to go out, insert each fuse that you left out individually. If the light comes on even a little bit, you have a draw on that fuse.

That should help you to narrow down which circuits are drawing power. Then you just need to isolate the draw to the component on that circuit that is bad.

 

[co04cobra]

Maybe I missed it, but the year of truck you are working on would be a help.

 

[cbf9703]

Dome lights missing so I couldn't tell ya lol

If opening the door doesn't trigger the door ajar light or interior/running board lights, etc. then it's probably just the sensor is out... not a big deal and is unrelated to your other electrical issue.