So our work truck has been dieing lately when left to sit. I have tested both batts with a tester they are okay. How do I check to see if there any draw on the batts when the truck is rest with everything off? I tried a clamp on amp meter but since I just figured out how it works on a real circut i dunno what I am doing.

 

Dis-connect a positive battery cable and hook you meter between the post and the cable, that should tell you if you have an at rest draw.

 

So a regular meter and not one them clamp around meters?

 

Yes, a regular DMM will work just fine for finding a draw. Agreed on 00' Quad Cab's with one exception. Remove the positive, or negative post, then touch it to the post again. At that point put one of each lead on the post and cable. This way if there is a draw there won't be a high amperage jolt to you meter when the circuit is closed. This may blow the fuse in your meter.
Remember to disconnect the other battery otherwise you will have an incorrect reading.

 

if you cant track it down easily... try removing the relay for the grid heater. mine was drawing just a little. but enough that if i let it sit for 4 days it would sometimes not start.
just a thought. i removed the grid heater altogether and have no prroblems starting it even in 20 degree weather here!

 

If you find that you have a draw, then to track it down pull one fuse at a time until you find the one that stops the drain. This will narrow the search down to the individual components.