New Alternator and Battery Still no Charge?

[washburn]

I am having a serious problem with my explorers charging system. I have already installed a brand new alternator and battery and it is still not charging so the battery dies and I end up stranded not able to start it. I have looked over everything to the best of my ability and I just cant figure it out and My wife is tired of me using her car, Please Help Me!!!

 

[frstxplorer]

Havwe you put a meter on the battery ? Whats your voltage? check It running , Voltage? check it under full load after about 15min. Running, Voltage? Where did you get the alternator & Battery what kind of shape are the battery cable ends in check the resistance in the cables, posibly corroded inside, Also you could have a draw on the system that kills it over night, Take off the neg. cable from the battery & connect a test light clip to the neg. cable end then probe to the neg post on the battey if it lights up you have a draw,have some one pull each fuse & breaker 1 at a time till the light goes out the fuse that makes it go out is the circuit with the draw then check the wiring diagram to trace wire & look for breaks Etc.
Hope this helps sorry its so looong
Drew

 

[washburn]

i have a question, does the vehicle,key, need to be in the on position when doing this test? because i did the test with the key in the on pos. and my test light only went off when i pulled the big 60 amp fuse from under the hood. then i tried it with the key off, and connected the gator clip to the neg term. and touched the post {neg} and my light was dim then went out. so im confused right about now, is it my ign fuse ,or is there still a draw some where???please help me if you can , thanks washburn

 

[410Fortune]

have you done anything to the interior recently?
the voltage regulator on teh alternator gets its power from the dash through the little battery light.
If the voltage regulator on teh alternator is not powered the alternator will not send out any power.
I could not figure out why I had a similar issue to yours, I know my cables are good, I rebuilt the alternator wiring harness a couple of times, tested my alt and my battery, etc. Turned out I didnt have my instrument cluster plugged back in all the way.....so the voltage regulator was not getting powered up on the alternator.


You should have around 14.4V at the battery at idle and also at the power wire post on the alternator.

 

[washburn]

yes the radio was put in a while ago like 4-5 months ago. and when i lost power to my truck the radio made a weird gurgling type sound and then my charging system went to zero that quick. can you tell me what wire color is the battery light and ill check it!!! thx again i hope this works, my fingers are crossed! thx , washburn

 

[410Fortune]

I wish I could, its the wire that leads to the battery light i can tell you that
you can check for power at the voltage regualtor, I believe its the yellow wire? with key in ON it should get the same voltage your battery is putting out

 

[washburn]

2nd new alternator and 1 new battery still no charge?

well heres an update to my major headache!!! since i posted last time , ive replaced the alt again , but still having the same problem i think. well i checked the voltage at the main red lead on the back of the alt, and it was reading 12.65 volts, so ichecked my battery next and it was reading 12.95 volts. i read and was told that the alt should read 14.4 v ,if not replace. well i replaced and still my battery is 12.8-9volts and alt, is in the low 12's{volts}SO IM ALL MESSED UP!!!! PLZ SOME ONE HELP ME ,AND GIVE ME A HINT ON WHAT TO DO!!!!PLZ,PLZ,PLZ, Thanks Washburn

 

[shamaal]

I have included a charging system drawing that shows colors etc. Charging system problems are difficult to troubleshoot as you've discovered because of the high currents involved. A connection that appears sound with a milli or micro amp load breaks down at 40 amps.

The problem may be a simple bad connection (most common) to something more exotic like the reference voltage coming from the control panel or the fusible link. I have seen a fusible link go bad on another car I had. I don't know wher e it is on the Exploere. It can be easily checked by measuring the resistance of the cable.

Assuming that all the connectors are cleaned and they do not twist on the battery I would recommend the following steps, consult diagram and ask questions if you do not understand.
I assume a familiarity with the multimeter for measuring resistance. As these are resistance measurements zero the ohmmeter.

1. Disconnect +12 connector at battery, leave - connector on.
2. Disconnect Alternator connectors.
3. Measure resistance from - post on battery to chassis. Should read <1 ohm. If not bad neg cable or connections.
4. Measure resistance from disconnected +12 battery connector to + cable on alternator (C122). Should read <1 ohm. If not, bad fusible link or connection.
5. Measure resistance on disconnected alternator connector (C123) pin associated with Y/W wire to disconnected +12 battery connector. Should read <1 ohm, If open bad fuse 12 in PDP or connections.
6. TURN KEY TO RUN. Measure resistance on disconnected alternator connector (C123) pin associated with LG/R wire to disconnected battery +12 connector. Should read <510 ohms. If not bad, bad switch, wire in fuse panel, instrument cluster or connections.
7. There is also the C121 to C120 single pin wire on the alternator, should read zero ohms.

I think that does it, I have a 91 Navajo so if the book and your vehicle don't jive, ask questions and we'll figure it out.

 

[toddleesupra]

Gosh i'm having the same problem on my 93 explorer, plz if you ever find out whats wrong with your car. send me an email!

 

[ken v]

thanks for the grest post I have a 2001 Ranger similar diagram and have 7 ohm between the C123 and positive connection. My book says that is a 15Amp fuse in the Eng Comp fuse box but the book is for a 2000 any idea if it is diffreent for a 2001, Also I would expect alot more resistance if the fuse was blown think this could be a connectore?

 

[shamaal]

When reading between an open C123 connector and the positive connection with the switch in the run position you should read <510 ohms. 7 ohms is less than 510 ohms. You are reading through the instrument cluster lamp. If the fuse were blown you would be reading over range.

Reading through the alternator is somewhat unreliable because of the active compnents in the regulator sense circuit.

 

[ken v]

Note on my 2001 there is an 18ga fuseable link between the C123 Y/W and starter relay, not shown in above drawing (or my Hanyes manual). Running an ohm meter between the connector and Positve terminal while moving the link gave me voltage spikes and after replacing corrected my issue. Note without moving the link I had .2ohm so thought all was good till I located the fuseable link and moved it. Thanks to all for the help, neither Napa, the local garage, or Ford Dealer came up with right answer