Ford Ranger Forum - Forums for Ford Ranger enthusiasts!

Go Back   Ford Ranger Forum - Forums for Ford Ranger enthusiasts! > >
Forgot Password? Join Us!

Welcome to Ford Ranger Forum

Thread Tools Search this Thread

Old 01-24-2015, 11:30 PM
ZacharyTaylor001 ZacharyTaylor001 is offline
Drivin' thru life
Join Date: Aug 2012
Posts: 73
Default 2004 4.0 alternator issues

Okay so I have a strange situation. So at first my battery light came on but only at idle. So I used one of those testers and tested it on the truck. It came back as a voltage regulator fail, so I attempted to limp it home and it died on me. So from that point I proceeded to buy a alternator from a salvage yard which was fine but I noticed the battery light came on after 3000 rpm, I checked it and the voltage dropped down as soon as I hit 3000. So I got a new voltage regulator and put it on the new alternator, same issue over 3000 rpm. I then took it back off and switched the voltage regulator to the old alternator (where I knew that was the issue). Started it up no battery light at idle and no battery light at 3000, so I was like sweet let's put a meter on it and see what's up. So the first maybe 1-3 minutes voltage was kinda crazy (8v-14). Kinda figured then little brush things were just trying to seat on it properly. After that period of time it remained steady at 13.7-14.6). I continued to watch it for another 10 minutes and it would go down to 12.4 volts and stabilize there, I was like okay so it's bad again? (Still no lights what so ever. I played with it and reved it up a little and it would go back up to 14.4 and stabilize there for maybe 1-2 mins than drop down to 12.8 and just chill there and it still does that after maybe another 10 minutes of messin with the throttle and let it idle but still no lights? So does that mean it's bad? Or it just stabilizes at a dead idle at 12 or maybe the Briggs are just trying to seat? Anyone have any advice or shed some light on what's going on?


Sorry I meant to post this is the 4.0 thread
~50 thru a residential neighborhood~ What were those people yelling?? Response: I dunno, I was going to fast to hear them
Reply With Quote
Old 01-27-2015, 04:28 PM
Mike In Bama Mike In Bama is offline
Electronics Tech
Join Date: Mar 2013
Posts: 1,194

If the truck is running ok now and there are no lights, I think you are fine.

The alternator will charge the battery to a certain level and stop! There is no reason to keep charging it. It looks like that's what is happening. Your battery is charging just fine.

Run it a day or two to verify everything is ok.
2005 2.3L XL 5SOD 3.73 K&N
KYB Shocks Husky Toolbox
Alpine / Rockford Fosgate Sound

"Ask me about my AC Vent fix!"
Reply With Quote

light, voltage, idle, battery, alternator, regulator, minutes, kinda, seat, rpm, issue, bad, stabilize, lights, time, remained, steady, 13.7-14.6, continued, watch, properly, period, volts, mins, briggs

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
2004 2.3 Ranger starting issues MPetrosino 4-Cylinder Tech 2 01-24-2015 08:30 PM
Alternator issues... I think. doublepedaldylan 4.0 SOHC / 4.0 OHV Tech 9 12-15-2012 07:07 PM
2004 ranger 4.0 temp sensor issues redneck15431 4.0 SOHC / 4.0 OHV Tech 3 02-11-2012 08:52 PM
2004 Light Issues JamesLearie Electrical Tech 6 09-22-2011 06:59 AM
replaced alternator and battery... Still have issues Wicked46 Electrical Tech 5 01-24-2010 11:56 AM