I have a problem with my battery drainning over a 5 or 6 day period I was told if I took both of the positive battery cables off and hooked up a test light between the main battery cable and the terminal if the test light came on it has a short. So I did this and it came on very dim and it pulses. I was told to take out all the fuses until the light went out and what ever that fuse was that made the light go out was were my short was. I did all this and no fuse made the light go out it is still on. I want to know if there is some fuses that I dont know about other than under the hood or inside the door, and maybe if there is someone who has had this problem let me know I am tired of buying batteries!

 

Did you also pull the relays under the hood?
Pull the turn blinkers?
Does it "pulse" fast or slow?
If all else fails, just install a battery cut-off switch.

 

Try unplugging white connector under drivers seat it controls seatbelts if you have a quadcab. Mine also drains batteries if sits for several days if I don't unplugg it, you can also pull yhe I.O.D fuse in dash.

jed

 

My '98 has done the same thing since new... I finally switched to Optima blue-top marine deep cycles and haven't had a problem since.

 

The test light method tells you nothing.
You need to have a D.V.O.M. and a switch installed between the post and cable(in-line) to properly test for parasitic loads.
All vehicles have parasitic loads. The D.V.O.M. used on the m/a scale will give you the correct information you need to properly diag. the draw.
On a car the load spec is 35 m/a and under. Our trucks with twin batteries should be able to hold a 40 to 50 m/a draw max.
You need the switch in-line so the PCM and other modules power supply is not interrupted. This way they can be properly tested for sleep mode and power down properly.
The switch keeps everything powered, when you hook up the D.V.O.M. across the switch it will kept the circuit live when the switch is opened. Open the switch and check the reading.
Wait 15 minutes and check it again. This is called time out. It`s how long it takes for the module to go off line. If its around 50 to 10 m/a it`s not the draw killing your batteries. If it`s over 50 m/a to 2 or 3 amps you`ll need to start the isolation process. Glove box lamp, sun visor lamp. ECT. Make sure the ignition key is removed from the cylinder. The key minder will activate and cause a false reading. ALSO BE ADVISED never open the door or activate a switch with the meter holding the circuit. You`ll blow the fuse.
If the draw is within the spec`s I gave you. 10 to 50 M/A you`ll need to test your batteries. Good luck and happy hunting. Check all the common stuff first. All your add-on stuff and then all the accessory stuff.

 

Small draws on batteries are really hard on them. Look into a Battery Minder to desulficate them. They will last twice as long. Even Optimas can be killed by slow draining them. Battery Minders break up the sulfer with pulses of electricity. I hook mine up when I go on a trip or when I know I'm not going to be driving for a few days. Does wonders for the battery level. A noticable difference.

Take a voltmeter and test your batteries after the truck has sat over night. Less than 12.4 and your drain is damaging the battery.

 

One thing that can really throw you off when determining the ignition off draw is the seat belt module. It's powered up for about twenty minutes every time you open the door.
Also make sure you disconnect the under hood light.

 

....and if you don't use a shunt the DVOM won't pass enough amperage for the controllers go into "sleep" mode.

 

If all else fails you can do like VW does. Plug in the solar panel attached to the windshield by suctions cups!