Battery lite on...new battery & altenator

[Coachman]

Hello All,
I have been computreless for some time now... How things change!
"Serious Explorations" has really taken off. Nice to be here, lots of Info.
03, Explorer 4.0, 4WD. Replaced original battery at failure, alternator (120amp) bad as well. battery lite never came on.
Installed new Remey alt.(130amp) battery lite on... All charging #'s good. swapped out another new Remey alt. lite on? New serpentine belt, all connections tight, that I can reach. Ford dealer took quick charging system check. "New Tech." Found nothing. No charge$, thanks! Said I needed to leave it for further testing. I was thinking of bolting up a Ford reman. alt.??
Any thoughts? Thanks. Sorry for rambling along, could have been said with fewer words Feel like a kid with new bike.
Tom C.

 

[Opera House]

Fusable link from alt to bat open.

 

[Coachman]

Opera House,
Thanks for the quick reply.
I stripped back some insulation back on each side of fusable link "C",
18 Ga. Orng / lt.Blu. had 12.5 volts each side w engine off.
14.82 V. engine running. Not sure from here...

Tom C.

 

[Opera House]

If you have over 13.5 volts at idle with headlights on, the system is charging. 14.8V sounds a little high at idle at these temperatures. I wouldn't want to see it go higher than that. The regulator should turn on from alternator light power. Charging with it on is unusual. I'll have to look at my 02 to see if things look different from the past.

 

[irocdupi]

Dont know why the light could be on but on my 03 XLT with the engine off my battery pulls a 12.5ish and with it running and head lights on i pull around 14.6 with the stock alternator

 

[FordLover]

just a thought, but have you checked all the fuses? When the alternator was being worked on, was the battery disconected?

 

[n2epv]

Check the engine block to chassis ground cable or cables. Corrosion on those will cause weird problems but don't seem to show up on a charging system test. Last time I had this problem was on a '96 Escort. Started out with batt warning light plus dim headlights and progressed to random 'no start'. I too started with checking battery, alternator and related cables. All were OK.

After 6 months of frustration, found that the road salt had trashed a ground connection from the block to the body which was hidden down low on the side of the engine. Cleaned it and then added my own additional ground between the block and the body. That fix lasted another 2 years until road salt corroded the rest of the car and it went to the scrap yard.