10SI alternator battery drain

[jfnar]

My battery started dying when the truck sat for a couple days. I started looking for a short and found that the #2 terminal was drawing current when not running. A test light will come on when I disconnect that wire and put the light between the wire and terminal. I had another alternator in my junk collection so I swapped it out and it's doing the same. Is there something other than the alternator that could be causing this? Any help will be much appreciated. Thanks.

Jeff

[vince1]

Your problem is of interest to me as well. It takes more than a month for my battery to run down so if not in use I usually take the ground cable off. I always thought that maybe it was the new radio I put in that is drawing current and some day maybe I'll have time to figure it out. Hopefully someone will have an answer for you.

[vince1]

What about if you disconnect the alternator wires and put your test light between your battery terminal and cable?

[jfnar]

Still lights up if everything else is disconnected. I took it to a napa store and they told me it probably has a bad diode so I traded in on one of their reman alternators. Checked it when I got home and it does the same thing. Maybe it's supposed to do that. I don't know how much amperage any of them are leaking; test light only tells yes or no. Hopefully the new one won't kill the battery. Time will tell.

[vince1]

I have the CS130 in my 64 AMC Rambler and it can sit for months without draining the battery.

I have the 10si in my truck and will try disconnecting it to help isolate the draw. If it is the 10si, I have a junkyard spare CS130 to use.