batteries go dead after two days.

[IPULLRV]

I found glove box light pulsing,removed fuse 51. light now normal. fuse box cover says- 20a cluster,radio uderhood lamp (do not have under hood light)radio dead. think this is cause of battery drain?. help PS -JUST GOT TWO NEW BATTERIES

 

[wcjp]

Since you have the fuse out, use an ammeter to verify the current draw.

 

[jelag]

You have some other draw... . a glove box light is not a large enough draw to drain the two batteries in two days... these are 100 amp hour batteries... assuming your replacements are up to standards...

An example of that is a 100 amp draw would drain 1 battery in 1 hour... . a 1 amp draw would require 100 hours to drain 1 battery... this is a simple math formula you can figure out... and of course you have 2 batteries... .

If you have something wrong with your charging system, or bad batteries, the above goes out the window as the batteries are not fully charged...


Some times short trippers, those who take very short trips in very cold weather don't allow the vehicle to run long enough to recharge the batteries and they will go down... .

A couple of simple tests... . if you can spin the alternator pulley the belt is too loose... . what your voltmeter gauge for the gauge to move from discharge at start up to charge 5-7 minutes later. .

Put an AC volt meter across the batteries... if AC voltage over 3-4 volts is present, one or more of the diodes in the diode bridge is bad in the alternator and the vehicle will not charge...

And with every thing turned off... remove the ground strap to one battery and place a DC amp meter between the ground strap and the post of the second battery, to see how much drain you have... .

Remember you might have to watch it for 15-20 minutes to see if something is turning on or off... ... cycling so to speak... based on what you said, and the ability of good batteries to function, you'd need a drain of more than 3-5 amps to bring the condition of the batteries to a point where it won't crank or start. .

Also remember that a bad connection, on the cables, solenoid or starter, and or a bad starter can cause the same problems... .

Hope this helps...

 

[E2360]

You said the batteries are new but are they good? More than once have I bought a Bad battery that was brand new.



1st check date codes on the batteries. They should be within 6 months from date of purchase and should be the same for both batteries. Seeing that our batteries are wired in parallel with no isolation, 1 bad battery will draw down the good battery pretty quick.



Just my 2 cents worth, hope it helps

 

[CKelley1]

you did not show year modle of truck if the fuses are under the hood it makes it easer to do what jelag suguested if on inside of cab wedge something in to keep the dor light from coming on disconnect both + battery leads set the meter to the 10 amp scale and place between one leade and battery there will be more residual draw the newer the truck and no. of options but usually less than 0. 1amps . as jelag states you are probabally going to see a couple of amps start pulling fuses one at a time untill you find the circuit you can also check for leaky diode by removing the large lead on the altinator if the load goes away one or more diodes are bad just remove the meter while removing the lead a 5/16 wrench pulls more current than the meter likes