1994 7.3 powerstroke battery draining

[Alan L.]

I know there have been several threads on this subject, but though I would share my experience. I believe I solved the problem as the result of what I have read on this forum. THANKS! My batteries kept going down, I've even had to replace them twice. I even paid a garage to find the problem and thought they had, but it kept happening. Once I got everything back together with hot batteries (see my thread about replacing the positive cables and starter reinstall problems), I did as I learned on this forum. I disconnected BOTH grounds off the batteries, then put a test light between the ground cable and the ground terminal of one of the batteries. Sure enough the test light lit up, maybe half or 2/3 as bright as it does with the full current across both posts of a battery. The first thing I did was pull the red wire on the alternator - still lit. Pulled the ignition wire off the starter relay - still lit. Pulled the large positive cable off the starter relay - bingo, light goes out. Must be the relay, so I go to the parts start, get a relay for $10 and replace it. No fix. then I got to thinking there are 2 other wires connected to the relay and indeed found that one of them, when I disconnected it, the light went out. No idea exactly where the wire went - it disappeared into a huge wiring harness. Probably lots of stuff inside the truck. So I open the door to the truck (they light really lit up then.....) got inside and closed the door and then proceed to pull fuses. Pulled every fuse and the light stayed on. Bummer... Then I remember this old CD changer some previous owner had bolted against the back cab wall. The only thing has never worked. I pulled the mounting screws and found a big thick power cable with a quick disconnect. Pulled it out and BINGO! Light goes out. Also noticed when I plugged it back in the light would come on AND the thing would make a noise. Pulled the thing out of the truck and into the garbage it goes! Seems like I should have thought of this to start with. Funny how the guy at the garage didn't come up with this. I am assuming that this fixed the problem, since the light no longer lit at all. Maybe this will help somebody sometime...... Whoever installed the changer also epoxied the control head to plastic dash. I guess its there for good....