Hello all, my daughter has a 2000 Ranger 4.0L (over 200K miles on body and trans, engine changed at some point years ago with junkyard engine). Last year, the battery would die overnight. I took my test light and did an amp test between the positive post on the battery and positive cable and it lit up, started yanking fuses and when the radio fuse was pulled it would go out, now it, at the time, had the OEM CD radio, so I figured after 16 years, 200K, an engine swap, and sitting for a year in a parking lot, the radio probably had a short in of itself, so we put in an aftermarket radio, and at the same time I brought the battery to work, charged it, and load tested it. The load test came back on the weak side and was borderline ok, so we replaced that as well in the process. Haven't had any issues since until now, granted its been single digits here in Michigan, but the battery has been dying overnight. She actually came home from work today, and I went out to look at it because she told me the CEL came on, so I pulled the code (misfire on #4, guessing it needs plugs and wires, they look shady/old, and the misfire is slight). After I pulled the code I decided to try and start it, mind you it had only sat for about 10 minutes, and the battery didn't have enough to start the engine. So I grabbed the multimeter and checked voltage, it was at 11 volts. So I put the jump box on it, got it started, checked voltage when it was running and it read 14.4V, good, the alternator is working! So I shut it off, put the meter on it again and I got 12.5, then about 10 seconds later 12.4, 10 seconds again, 12.3..........dat ain't right. So I thought OK, maybe the voltage regulator is shorting out on the alt and draining, so I unhooked the positive and took a reading, 12.4 and was holding, good. I then unhooked the plugs and battery cable from the alt, checked the battery again and it was still at 12.4, hooked the positive back up, 12.4.......12.3........12.2........ok, alt isn't the problem. So again, I hooked up my test light to the terminal and the cable, lights up, yanked the radio fuse and it goes out.......

So, my question is, where do I attack next? I can't see 2 radios shorting out in the same manner within a year. I'm guessing there HAS to be a relay or other....THING that the radio fuse also powers?

Other thoughts I've had while browsing the nets is....is the alternator actually bad? I read on another forum about the alternator on these running at 14.5V for about 5-10 mins then dropping down to 13.6 (I didn't confirm as I couldn't feel my jewels anymore after working on it) and it has actually fried a cell in the battery, and while the trucks...GEM(?) is doing its thing for 30 mins that its killing the battery? But from what I can tell the GEM is on a seperate fuse? I'm not 100% sure where to diagnose next. I left the radio fuse pulled for the time being as she has to work tomorrow (a starting and running vehicle without a radio is better then a NON starting/running vehicle WITH a radio IMO) When she gets home from work tomorrow I'm going to have her leave her truck running and see what the alternator volts are out've curiosity (she has a 15 min drive home from work, plenty of time)

So any thoughts or ideas on where to attack next would be greatly appreciated, we picked this truck up for $400 and put $2K into it, and it runs drives and shifts AWESOME, just this little pickle......other then the misfire of course, but I think that will be an easy fix

Thanks!!

 

Welcome to the forum


2000 Ranger will have a Battery Saver Relay circuit, and it will draw .3-.5amps with key out, but only for 20-30min, then Battery Saver Relay will open and it cuts power to any lights or electrics that may have been left on.
After battery saver relay opens amp draw will drop to .03-.05amps, so just radio clock/preset, keyless entry and computers KAP(keep alive power) which would take over a year to drain a working battery.

If battery is unhook from vehicle and battery voltage drops when volt meter is hooked up then yes battery is self draining, shorted cell, so needs to be replaced.

With battery hooked up you need a clamp on amp meter on battery cable.
Turn key off, doors closed, hood open light disconnected, the see what amp draw is, .3 to .5 is normal, then wait for 20-30min, and test again, should have dropped to .03 to .05
If it is not dropping the GEM(generic electronic module) is not opening Battery Saver relay, this could be GEM issue or relay issue
GEM is behind the radio
Battery saver relay was moved around a bit but usually in Relay Box 1 above gas pedal area, has several relays in that box

What is the fuse number that you pulled out?

 

Ok thanks, i will check those tomorrow after work because apparently shes going to a friends house now tonight

I didn't have any battery voltage drop during the 5 or so minutes it took me to unhook the alternator, but that may not been enough? Even though it was dropping quite quick with the positive hooked up


IIRC it was fuse 28 or 29, according to the manual it is only labeled as "radio"

She told me she had to jump it to start it this afternoon, and i left the radio fuse out all night, and let it run for about 10 mins after pulling the fuse.

I'm really starting to suspect the battery is bad again, and i'm fighting a bad alternator in all reality as in its charging at 14+ volts at all times and not dropping to 13ish and boiling the battery, it is a oreilly ultima alternator, so it wouldn't surprise me if its junk

 

Could be alternator, they WILL run down the battery if not disconnected from power when engine is off.
They are in essence an electric motor so if you gave them 12v you could get them to spin, but with fan belt on they won't spin the engine, lol, but would run down the battery.

If you disconnect B+(wire on back of alternator), and unplug the 3 wire connector then alternator is isolated, battery drain should stop instantly if that was the problem.

Voltage regulator works by "electrical back pressure".
A drained battery after starting engine has less "back pressure", so voltage regulator pushes voltage up to above 14volts, the higher the volts the lower the "back pressure".
As battery gets reCharged "back pressure" increases so voltage regulator lowers the voltage to 13.5volts when battery is fully reCharged.

When you turn on lights or fan blower, back pressure drops, and voltage regulator responds by increasing voltage but amp draw keeps it at 13.5volts

A bad battery could cause voltage to stay above 14volts, because battery isn't reCharging fully, so "back pressure" stays low

Below is 2000 Ranger Power distribution, fuse number must be exact

 

sorry I haven't updated, I haven't really been able to go out to do anything because yesterday I decided I didn't like the looks of my left hand and stabbed my knife into it at work and got 8 stitches (har har)

RonD, when I said the radio fuse I meant from the fuse block from inside the cab on the drivers side, all those .pdfs look like they are from the main block under the hood? I may go out and mess with it, but its freezing outside, and I'm leaving the gauze off my hand for a bit to let it air out for awhile.

 

It will say Battery Junction Box for the engine bay fuse box
Central Junction Box for in-cab fuse box

Sorry about your hand, hope 2018 goes better than 2017 ended, lol

 

So.a quick little update, yesterday after she got out've work the battery wouldn't start the truck at all, even with a jump from another vehicle or the jump box. So my g/f went and got the daughter and took the battery out (yes, i have one of those awesome g/fs) and she brought me the battery to my work. I put it on the trickle charger (1.25a) and let it charge through the night, when i got to work this morning i load tested it and it tested good, had 13v when i unhooked it, and only dropped to about 10v while under a load, and i tested it twice. I'm letting it charge back up, gonna check the voltage on it then set it outside in the cold for a couple hours and try it again and see what it reads, but so far the battery is fine

Mind you, this is still with the 15a radio fuse pulled.....so the radio obviously isn't the issue

 

update #2, battery is good, I load tested it 4 times, twice room temp, twice sitting outside for about 4 hours, only dropped down to 10v under the load tester 15 seconds per test. So I charged it back up, dropped it into the truck at her work and it fired right up. drove it home, and when I got home I shut off all accessories and grabbed my volt meter, at idle (and hot, after 15 minute drive) I was at 14.5V. So I turned on high beams, and cranked the heater (the heater in this truck is AWESOME) and it dropped down to 14.4V. So.....in my opinion, there is nothing wrong with the alternator either. I switched my meter over to Ohms, and probed the negative of the battery to the body ground right at the core support, and I have some resistance, which changed while I moved the wire. I then switched back to volts, and went to the same ground on the core support, then positive, and I got under 12V. So, numero uno thing getting changed is that ground wire to the core support, and I figured I would add another from it to the ground thats on the drivers fender.

Could I get lucky and have it all be the grounds fault? I'm not sure, but its and easy change, and it obviously needs to be changed......and I like easy.

I haven't checked the GEM status yet, I need to make a quick jumper wire to keep the battery and positive cable connected so I can wait the 30 minutes, planned on doing that tomorrow after a dr. appt

 

Self draining battery will be fine for load test
Load test is to check how many AMPs battery can release in a short period, it basically tells you how many times battery has been used for starting.
Each recharge, after starting, stores less and less AMPs and at about 5 to 6 years old they just can't store enough AMPs, but won't discharge overnite either, battery just can't discharge enough AMPs quickly enough for starter motor.

best test would be to disconnect battery when it sits, overnight, then reconnect it when you need it again, if it won't start engine or starter turns slowly then battery is the problem, self draining.
If it starts right up then you have a system drain, something is on and shouldn't be with key off, doors closed, which is what this reads like

 

I forgot to mention Ron that i did unhook the positive cable from the battery for the night and it was around 12.5V when i unhooked it. Part of the plan tomorrow was to check the voltage in the morning and see if it would start as well

 

Good plan, that will seal the deal, battery or vehicle drain

 

ok, so battery as suspected is good, went to it this morning, had 13V, hooked it up, started the truck...slightly sluggish, but its single digits right now with a negative wind chill, so it doesn't surprise me.

I remade the ground going to the core support. made sure it started, it did, good. so I unhooked the positive, had a length of small wire, wrapped it tightly on the positive on the battery, and around the positive cable, opened the door, light came on, good. I checked the amps and the amp draw was 3.8 amps. After 30 mins, dropped to 2.5 amps. I came back in to warm up for a little bit, but I'll have to go back out and start pulling fuse's from side and see which one drops the amperage........I can almost guarentee it will be the radio fuse as I put it back in this morning while working on it. But I have a feeling there will be another fuse that I pull that drops the amps also

 

I didn't make it long, the temp is dropping quick and the wind is picking up

I need to buy a clamp style meter (expensive, but still cheaper then having a shop diagnose this), because doing it with a wire jumpering the 2 connections changes amp readings all the time, that and my amp meter doesn't go down far enough for checking miliamps, best i can get out've it is .0 nothing lower, so about all i've found out today is that something is draining the battery......really hate when minimal info is found in a large time frame

 

So update time. I never made it back to check amperage draw on the truck friday, i helped my brother all day diagnose his truck as to why it wouldn't roll over, but i drove the ranger all day friday without a hitch, and the daughter hasn't had to unhook the battery and its been starting after sitting through the night, even the last subzero night we had it started the next morning

So the new ground wire and cleaning has fixed it.....thus far, but being it hasn't given any guff in 3 days, i would like to think its fixed

Thank you very much for all the info you supplied Ron

 

Thanks for the update, it will help others with similar issues

 

Well, knew it was too good to be true, it did it again, and its single digits again. She's been having to watch her dome light cause of the common door switch issue. I've sprayed with lubricant and opened and closed all 4 doors multiple times to try and work them. She says the light was off before she went into work

So tomorrow i'm gonna be back at it, but i have a question on something that has confused me......if opening a door resets the GSM, how do you pull interior fuses after the 30 minutes? Especially with the dome light

 

So I pulled the dome bulbs out and did the amp draw.. it was at 2amp draw at first, then after 30 mins it dropped down to .15 amp draw. So out've curiosity I opened the door, amp drap was 3, closed the door, went back to 2 amp, then again after 30 mins it dropped back to .15amps. So, as far as I can tell, the truck is doing what it should be. I'm wondering if....even though the cab light is going out, if the switch isn't making full contact and is shorting out. I left the cab bulbs pulled for now and will see what that does

 

Yes, still a little high, .03-.07 is what is expected after 30min(battery saver relay opens)

Keyless entry and alarms can be troublesome for amp draws since they need to be "aware" 24/7 or are of no use, lol.
PATS is not an alarm, it is only active after computer starts up, key on

Only other draws are computer and radio KAMs(keep alive memorys) to hold info like IAC/TPS and clock/presets
The GEM also has KAM I believe

 

Well i'm stumped so far RonD, i thought .15 amps was decent, the truck has been starting fine until this morning, needed a jump, so whatever is doing it, is very random, and with it being random makes me think a hanging/sticky relay. I wish i could find (locally) a clamp style meter that does DC amps, but all i find are AC amps, so my only option is to jumper the cable and battery with my jumper cables

I'll pull under hood fuses next time i check it, i'm still not sure how to check the interior fuses without resetting the GEM and sit in the truck for a half hour, even then i can't get to the fuses because of the door, so i'm REALLY open to suggestions lol