Altenator not charging battery on load
#1
10-18-2011, 10:44 PM
Altenator not charging battery on load
Hey Forum
im looking for some help with my 1999 F150 4.6L 4x4
after frying a 130amp ALT. I decided to come here. This is the deal
All accessories/guages died amid a drive but still ran, made it to a garage where it eventually stalled/died at idle.
Battery was charged, failed a hydrometer test got to the parts store to be tested apparently debunking the hydro test and passing THEIR test with 100% charge.
Install new 130amp ALT, it was shown to me to be holding power to the battery just fine, but when I was asked to turn on the lights, the battery then began to slowly drain unless I had the engine revving real high.
My Theory is a possible bad/not strong enough connection somewhere in there did not allow the battery to charge properly, thus overworking the alternator and frying it.
I was told that it could possibly be a faulty wire connection running from the ALT to the battery and apparently this also included wiring to the starter as its all connected, I was also told it could be the "fusible link" cable which I can and only could get direct from FORD only.
Any input would be much appreciated.
Thanks
Sean
im looking for some help with my 1999 F150 4.6L 4x4
after frying a 130amp ALT. I decided to come here. This is the deal
All accessories/guages died amid a drive but still ran, made it to a garage where it eventually stalled/died at idle.
Battery was charged, failed a hydrometer test got to the parts store to be tested apparently debunking the hydro test and passing THEIR test with 100% charge.
Install new 130amp ALT, it was shown to me to be holding power to the battery just fine, but when I was asked to turn on the lights, the battery then began to slowly drain unless I had the engine revving real high.
My Theory is a possible bad/not strong enough connection somewhere in there did not allow the battery to charge properly, thus overworking the alternator and frying it.
I was told that it could possibly be a faulty wire connection running from the ALT to the battery and apparently this also included wiring to the starter as its all connected, I was also told it could be the "fusible link" cable which I can and only could get direct from FORD only.
Any input would be much appreciated.
Thanks
Sean
#2
10-18-2011, 11:48 PM
Yes you do need help if the situation has not been cleared up by parts changes.
You were told a lot of things that are just causing confusion.
First we need to have some answers.
Is the charge lamp on at any time?
If yes, there is a problem.
If no, go on and test battery voltage.
To know if the alternator is able to charge the battery, you need to use a voltmeter at the battery to observe the voltage.
If the voltage is at 15 volts + just after starting then drops as a few minutes later, the alternator lead circuit is complete and Alternator is outputting.
If the battery with a full charge cranks and starts the motor, the start circuit is good.
What conditions do you have, then we will try to sort it out.
You were told a lot of things that are just causing confusion.
First we need to have some answers.
Is the charge lamp on at any time?
If yes, there is a problem.
If no, go on and test battery voltage.
To know if the alternator is able to charge the battery, you need to use a voltmeter at the battery to observe the voltage.
If the voltage is at 15 volts + just after starting then drops as a few minutes later, the alternator lead circuit is complete and Alternator is outputting.
If the battery with a full charge cranks and starts the motor, the start circuit is good.
What conditions do you have, then we will try to sort it out.
#3
10-19-2011, 08:26 AM
--when the alternator dies, the battery will run the truck for a period of time, and the gauges will die out... that is correct, that is what happened.
-- after charging a battery you need to run a LOAD test. YOu can have a dead battery that reads 12 volts on a meter, but will not put out LOAD on a truck.
--a new alternator could be a problem also. no guarantee it is a "good" alternator.
--your theory about bad wiring terminals is justified, but you cant measure where that is, you will need to look at all terminals, and disassemble those that dont look good.
---also look at the "other end" a bad ground on an alternator will not allow it to fully charge, just like a bad power cable.. check all ground.. look for warm/ hot terminals when in use. High resistance (bad terminals), will get hot.
-- after charging a battery you need to run a LOAD test. YOu can have a dead battery that reads 12 volts on a meter, but will not put out LOAD on a truck.
--a new alternator could be a problem also. no guarantee it is a "good" alternator.
--your theory about bad wiring terminals is justified, but you cant measure where that is, you will need to look at all terminals, and disassemble those that dont look good.
---also look at the "other end" a bad ground on an alternator will not allow it to fully charge, just like a bad power cable.. check all ground.. look for warm/ hot terminals when in use. High resistance (bad terminals), will get hot.
#4
10-19-2011, 11:44 AM
The charge lamp or (battery light) is no longer on
It was weird because I ran the truck for a week with the battery light ON, started and ran fine until that one day the gauges dropped.
The Partsouce guy tested my battery with a little thing off truck saying it was 100% then on my truck running put that same device on again and could show me that this bar was a full on idle (guessing the full bar was 13.6v or greater) until I turned my lights on the full bar dropped unless I was revving extremely high. Assuming there was a intermittent/faulty connection.
So the battery was holding stable power on idle, with load failing. I didnt notice the lights fading I should have checked that too.
It was weird because I ran the truck for a week with the battery light ON, started and ran fine until that one day the gauges dropped.
The Partsouce guy tested my battery with a little thing off truck saying it was 100% then on my truck running put that same device on again and could show me that this bar was a full on idle (guessing the full bar was 13.6v or greater) until I turned my lights on the full bar dropped unless I was revving extremely high. Assuming there was a intermittent/faulty connection.
So the battery was holding stable power on idle, with load failing. I didnt notice the lights fading I should have checked that too.
#5
10-19-2011, 06:15 PM
Did a bunch of "field" tests today, took it back to another parts source store where everything checked out fine. Where I never noticed the lights dim on a full load
With the truck off the battery is 12.89V
running with the full load (ac, highbeams interior lights, radio) it went down at idle to 13.86V which I felt was still withing the normal 14-15v with running engine parameters. I turned all the accessories off and within in 10 mins at idle it recovered to 14.15V while running.
Im starting to think everything could be fine, it was just the ALT. and that one dude making me worry about the rest of the mumbo jumbo.
however looking back dude did say though that it could be a problem with my connections even to my starter which I took a look and seemed pretty corroded.
With the truck off the battery is 12.89V
running with the full load (ac, highbeams interior lights, radio) it went down at idle to 13.86V which I felt was still withing the normal 14-15v with running engine parameters. I turned all the accessories off and within in 10 mins at idle it recovered to 14.15V while running.
Im starting to think everything could be fine, it was just the ALT. and that one dude making me worry about the rest of the mumbo jumbo.
however looking back dude did say though that it could be a problem with my connections even to my starter which I took a look and seemed pretty corroded.
Thread
Thread Starter
Forum
Replies
Last Post
19-F250-78
1973 - 1979 F-100 & Larger F-Series Trucks
15
11-04-2012 07:57 AM
batmanincoralville
1987 - 1996 F150 & Larger F-Series Trucks
8
03-22-2004 11:22 AM
