Ive got something suckin my batterys dry, I tried pulling fuses to see if I could find what was doing it that way, but no dice. I know ive been having trouble with the intake warmer or whatever that is draining it when i crank it. Its supposed to go off after so long, but u can watch the alt guage and see it keeps comin back on and suckin the batt. Whatever it is is so much ofer a drain when i tried jumpin it, it suck the other cars batt dead and killed it too.Iwouldve thot that if it was that bad it wud have to be a direct short, but that would surely burn something up...right? HELP HELP HELP!!!!!!!

 

What year truck?

 

its a 1999

 

Are your grid heaters not disconnecting? Maybe it is the heater relay? This is the only heavy load other than something fried and shorted, in which case you'd see smoke and other visible evidence of a bad day. Pull the grid heater relay and see if the load goes away.
-P

 

You have had the Alternator output tested right?

 

You may have one of your batteries shorted internally. This would pull down the other battery. Unhook them and test them. If you have a bad one only hook up the good one and try it overnite. You will know if the battery just shorted or a drain from the truck killed it.

 

If both your batteries are dead, they will suck down a jump start vehicle pretty easy.

 

Could you fill out your sig, please?

Do the grid heaters come on even if you're driving?

How old are your batteries?

 

Batteries.

Have your batteries checked (they have to be disconnected from each other for a valid test).

Replace both batteries even if only 1 is bad.

The grid heaters are supposed to cycle on/off after start when it's cold until the computer sees a certain engine temp or vehicle speed.