Topic: I need help alternator/battery problem

[scars4x4]

I bought someone else's project.  It's a 1985 Toyota pickup 22r.  The problem I'm having is that the alternator doesn't seem to be charging the battery, but the battery goes dead when I drive the truck.  I've had the alternator tested twice and it tested good both times.  I can jumpstart the truck and it will run until I turn it off whether the battery is charged or not.  That leads me to believe that the alternator is good.  I have a redtop battery that I bought new and it's been replaced twice under warranty.  I tested the line that comes off the alternator to the battery with a light tester and the light comes on when the battery is not hooked up.  So, it looks like the battery is getting power, not sure if it's not enough power.  I don't know if it's missing a relay or its not hooked up or a ground wire is off somewhere....I don't know.  Any suggestions are most appreciated. 

Thanks in Advance.

Rick

[Rockdiver]

check the connection of the wire 10 gage or so from the positive lead of the battery to the fuse box . I think it might be a fusable link . mine was loose and I was getting a similar problem

[scars4x4 [OP]]

Is that the white wire?  I'll check it out tomorrow.

Thanks

[emsvitil]

When running, test the voltage at the battery and at the alternator post.

If the alternator post is much higher than the battery, see reply #1............

[Cheesemaker]

My BIL had the exact same problem.  We went through everything we knew.  Battery, alt, wires between the fuse box, and battery.  He ended up taking it to a mechanic, and he traced the problem to a wire that went to the carb, of all things.  I wish I knew what wire it was, but it was loose.  Hope this helps for an area to look at also. 

[Nimyad]

I had a problem like this on an 81. Ended up my alt wouldn't put out enough juice to charge a yellow top so it kept killing alts.