2009 ranger, why would i have .25 of an amp parasitic draw on the cluster battery feed b+ fuse? Manual says 60 miliamps is acceptable, not 250.

 

You need to wait 20-30 minutes after key is out and doors are closed before testing amp draw.

Most vehicles have a "Battery Saver Relay", what Ford calls it, that stays closed for 20-30min, then opens which cuts power to most relays for lights and other draws, so if something was left on power would be cut "saving the battery" lol
The .25 amp draw is the Smart Junction Box(body computer) asleep but not off, it has the timer that opens battery saver relay.

The 60 milliamp draw will be the Keyless entry(it needs to be awake all the time), the PCM and radio KAM(keep alive memory), also PATS theft light.

 

​​​​​Ok... Simple question, say that .25 amp draw was constant. Could that kill a battery in a day? Check my "floating ground" thread for the background on this. Im trying to figure out what killed my battery and all i found was the . 25 amp draw.

 

Car batteries are rated in CCR, cold cranking amps but generally they can be 100ah, 100 amp hours
So can deliver 1 amp for 100 hours or .25 amps for 400 hours
You do need 50-60 amps left to start the engine so cut that in half

Disconnect battery from vehicle and test voltage, retest after 1 hour, should be EXACTLY the same.
Car Batteries are made from 6 cells, in each cell are plates that are ALMOST touching, and the almost part is the big deal.
If 2 plates get connected then that cell will start to self drain taking the whole battery with it
The plates exchange electrons when discharging and charging, this exchange can cause tendrils that can meet, which causes the short between the plates.
Over time debris will build up at the bottom of the battery, this can cause a short.

But test your battery and see if it is self draining, there is no "fix" for it, but it will confirm that's your problem or it isn't

After battery has been discharged and charged a few thousand times the plates have lost electrons so can't hold as many amps
That is reflected in at rest battery voltage, after battery sits for a few hours.
12.8v is a new battery
12.5v is 3/4 year old battery
12.3v is 5/6 year old battery, and time to shop for battery sale

As the battery loses amp storage it can't take long term amp draws very well so leaving a light on over night won't bother a new battery but could cause a no start in 5+ year old battery

 

The battery after sitting 2 hours read 12.6 then after sitting overnight still reads 12.6 volts. I also re-did the parasitic draw test after having everything off for 12 hours. I latched the doors manually last night so the switches wouldnt turn anything on. Still drawing 250 ma unless I yank the cluster fuse. Im just at a loss now for why it randomly died. Its working fine now apparently. Still dunno why the cluster wont shut off even overnight but by your math no way that would kill a battery in 24 hours.

 

Hi,

I have a 2007 Ranger 2.3 with maybe with the same parasitic draw. Fuse #33 leads to the instrument cluster and the SJB, when i pull the fuse no more drain (.140ma) and my battery will not be dead after two days. Been dealing with pulling the fuse every time i park for the night for three years now...uggl! Did you ever solve your problem?