Electrical Drain (1 Viewer)

[thx3232]

Hey there,
I have an 1984 diesel, 60 series wagon.
About a month ago it suddenly started draining the battery when left over night. If I unhook both battery terminals when I turn it off the batteries hold a charge. (I just bought 2 brand new batteries. Something is still draining them if left connected overnight.) The alternator is charging fine if the batteries get low.
The one thing that I notice has changed is that when I turn the key on to start, the glow plug light comes on and then goes off immediately. It used to stay on for about 3-4 seconds before going off. Now just flashes on then off right away.
Could there be an electrical problem involved with the glow plugs that is killing the batteries? I pulled the glow pugs themselves and they look fine. Don't seem burnt out. And the truck starts fine as long as the batteries are not low.

Any ideas would be appreciated.

Thanks,
Corey

 

[Ron R]

you can check the drain by pulling the fuses and inserting them one by one. As soon as the current increases when you insert a fuse, you know the drain in in the part of the harnass feeded by that fuse.
Another thing is the alternator. I f one of the diodes in the alternator has a short, this can drain the battery as well.
You can check this by disconnecting the alternator and measuring the drain. If the drain increases once the alternator is connected again, that's the culprit.

 

[Garry]

I've had similar issues with my 60 for over 10 years now but the batteries discharge over a month of non use not one night!
I would do some tests like Ron suggests - could be something really simple like a dodgey relay