battery draining over night

[JOELPADGETT]

I have seen alot of threads on this however, I'm not finding enough info to help me so I will present it again.


I have a 91-92 ford ranger xlt. It is draining the batter within 12-20 hours depending on if I fully charge the battery on a battery charger. I have a multimeter, I pulled open the power distribution box and pulled each fuse one by one and it nothing stops the electrical pull on the battery.

When using my multimeter I have it set on the 10A mode and it reads 3.42 to 3.47.....

I do have a after market head unit installed. This has been in the truck for multiple years and never caused an issue. MY reverse lights have gone out recently. No other issues that I know of are happening.

I'm not a electrical expert, this is my first time trying to trouble shoot something like this. If I need to provide more information please ask.

I appreciate anyone's help with this. Currently it is my daily driver....

 

[-tristan-]

Battery Drain Test

get an inductive dc ammeter (if you have fluke meter, i believe they have attachment) and parasitic load shut-off tool

*ensure everything is off including dome lights
*install parasitic shut-off of battery negitive
*start engine, drive for 10 minutes, turn on all accessories
*turn engine and all accessories off, including hood light
*connect ammeter across parasitic load tool switch, wait 20 minutes for all circuits and computers to shut down
*open switch on load tool, read battery electrical drain on meter display, normal draw 20 to 30 mA, max draw 50mA

find source of drain:
*disconnect underhood light, glove light, trunk light
*if draw still more than 50mA, diconnect one fuse at time until excessive drain returns to normal (do not reinstall fuses after removing as may cause inconclusive test)
*If located componet/circuit causing draw after fuse pull, continue to pull + connectors from each componet on that fuse until test light goes off. You have isolated the defective component/circuit
*if excessive drain still exists after pulling fuses, source is between fuse box and battery.
*Common sources are alternator (disconnect alt wires and retest. if this fixes- problem is defective diodes)
*Common source also- starter solenoid or wiring near componets (test for excessive resistance in wires)
*You can check battery wires for high resistance too

YOu mentioned reverse lights, check that circuit first for high resistance. Have AutoZone test the charging system (battery, cables, alt, starter, wires) first.

Good Luck.

 

[-tristan-]

...or just disconnect battery at night :

 

[Bruces expo]

Welcome Fellow Georgian , I Would Also Recommend Taking It To Have All The Main Sources Of Power To Get Checked First , Then Follow -Tristans- Battery Drain Test , Make Sure To Come Back And Let Us Know , There's Alot Of Info On This Website