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troubleshooting power discharge when sitting

RootBreaker

RootBreaker

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Ok so now I am tired of being stranded occasionally...


so my truck when sat for a week would have a dead battery... now I have dual batteries and 2 weeks later the truck is dead.... anyhow I know... just drive it alot and it will be charged all the time... however I gotta figure this problem out....


is there a way to tell what circuit the power discharge is from?
I put a new alt in so that wasnt it...

I am going to unhook all accessories that plug into the fusebox to see if that does it.. but is there any tricks that people know of?

thanks
Jeff
 
Simple.

use an ammeter too see that there is a load on the battery. One you see it on the meter, start disconnecting loads by pulling fuzes and unplugging devices until you see the current drop.
 
readymix said:
Simple.

use an ammeter too see that there is a load on the battery. One you see it on the meter, start disconnecting loads by pulling fuzes and unplugging devices until you see the current drop.
Click to expand...


aight so first make sure my batteries are charged.... charging now..

then connect amp meter... so usually I use the volt part.. to use the amp meter.. you need to disconnect a battery terminal... and put the meter in between the meter and battery right? so say.. .red to positive cable and negative to positive post on battery???? get reading.. start popping fuses out and when the amps go up i got it???

thanks
Jeff
 
Exactly, just be sure that you don't try to measure too much current. Most DVM's are only good up to 10A. If you do it will just pop the fuze inside the meter. Simple to fix,......if you know it is there. Also when the fuze is bad the meter (most of them do) will still function fine on VDc and Ohms.

Just for comparison...the underhood light in my 98 drew just over 2A. Also keep in mind that your radio will draw current for the clock and memory settings so when you disconnent that you will notice a change in current drawn.
 
test light works too..

You can remove the ground cable and put your test light,or any 12V bulb between the cable and the battery terminal to locate shorts or current draw too..the bulb will light if something is "on",like the dome light,etc.--be sure everything is turned off,then if the light is still on,start removing fuses until it goes out..the curcuit that pulling the fuse put out the light , has a short or something draining juice..

If pulling out all the fuses doesn't put the light out,it could be a bad diode trio in the altenator.(or a short in the wiring that is "hot" all the time,like headlights and altenator wiring).
There are 3 diodes (hence the name "trio)--but if only 1 or 2 go bad,it will still charge-(at a lower rate than normal) but will let current flow back to ground and kill the battery eventually..(Clocks and stero's with "memory" drain some juice too,and will croak your battery if it sits long enough too).. :crazy:
 
readymix said:
Exactly, just be sure that you don't try to measure too much current. Most DVM's are only good up to 10A. If you do it will just pop the fuze inside the meter. Simple to fix,......if you know it is there. Also when the fuze is bad the meter (most of them do) will still function fine on VDc and Ohms.

Just for comparison...the underhood light in my 98 drew just over 2A. Also keep in mind that your radio will draw current for the clock and memory settings so when you disconnent that you will notice a change in current drawn.
Click to expand...

aight understood... I have a alpine in my truck connected to battery.. maybe should move to ignition???? nahhh if I do that then I will loose the memory..

oh well.. thinkin of getting ready to remove engine tomorrow anyway... :bow:
 
Also check your batteries- depending on how you have them hooked up they can drain each other. They don't neccesarily have to be bad, but different sizes or styles can cause them to battle back and forth trying to "equalize". I fought that problem on mine after I hooked up duals and bought 1 new battery.
 
Stoner42 said:
Also check your batteries- depending on how you have them hooked up they can drain each other. They don't neccesarily have to be bad, but different sizes or styles can cause them to battle back and forth trying to "equalize". I fought that problem on mine after I hooked up duals and bought 1 new battery.
Click to expand...

I had this problem before dual batteries..now I have dual 1000ca batteries... both the same part numbers... :bow:
 
alternator

Don't place too much trust in that new alternator - they can be bad too from the get-go. Before I traced too many circuits, I would take that alternator to at least one auto parts store for a test.

My truck was having the same symptoms. I had the alternator tested by one auto parts store who said it was fine. Spent another couple of months getting stranded and tracing ciruits. Then I took the same alternator to another store who diagnosed it as low charging (can't remember the numbers) so that it did charge but not enough to recharge the battery. I got a new/rebuilt alternator (which I had the store check before I hauled it out the door) and my problems went away.
 
Keith in CO said:
Don't place too much trust in that new alternator - they can be bad too from the get-go. Before I traced too many circuits, I would take that alternator to at least one auto parts store for a test.

My truck was having the same symptoms. I had the alternator tested by one auto parts store who said it was fine. Spent another couple of months getting stranded and tracing ciruits. Then I took the same alternator to another store who diagnosed it as low charging (can't remember the numbers) so that it did charge but not enough to recharge the battery. I got a new/rebuilt alternator (which I had the store check before I hauled it out the door) and my problems went away.
Click to expand...

thanks for the tip...

i think i got it figured out... gonna buy a 1987 1 ton with 454 in it.. if ya read my other posts... :bow:

my truck will get the 454 and all the wiring.. so theoretically ripping the guts out of the 78 and will think it is a 87... or the 87 will think it is a 87 and be a 78 :haha:

that should fix my problem :wink1:
 
Keith in CO said:
I had the alternator tested by one auto parts store who said it was fine.
Click to expand...

Similar problem to original poster with battery dying after sitting for one week. Draw with the ignition off appears normal, so no issue there. Even fully charged the battery won't turn the starter more than 15 (cumalative) seconds before it's low enough to be worthless for cranking. (checking with friends, it should turn a lot longer than that) Battery is just a year old.

Took it to chain store for "load testing" and it came back as good, which is definitely not true. (8 volts while cranking is good??) Everytime one of these normal batteries (I believe the Optimas are different, as are deep cycle) gets completely discharged, it's overall effectiveness is permanently lessened. Just because something is tested doesn't mean it will work right in an ACTUAL working environment.
 
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