thenaes

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

akdoggie

Have you done a test at the battery for voltage, running? You should read running, 13.6 or better (approx). If you are getting this reading then your alternator is putting out the correct voltage to keep your battery fully charged with the lights on. If your lights go dim when engaged, and the alternator is new, then your battery isn't storing the energy correctly. Most likely a bad cell or plates.

I've never seen a battery fail the hydrometer and pass a full load test. If you have another battery to try, I'd put that in there and try it out. I'll be willing be bet that the internals of the battery are bad.

Keep us posted.


QUOTE=thenaes;1137624]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[/QUOTE]

thenaes

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.

azmidget91

If you drained the battery till the truck died you will need a new battery

thenaes

to my knowledge if a battery dies it can be recovered as long it is not left dead in the extreme cold or left dead for an extended period of time.

techrep

iTrader: (1)

The battery has nothing to do with running the truck once it's started...thats the job of the Alt. You have a short to ground for your charging system...check all your cables and connection points to the frame...The Alt re-charges the Batt after start up...that's it ...and yes the Batt should still be good unless you cooked some cells. The power from the Alt tring to go to the Batt after engine start up is going somewhere else...the frame of your truck I would guess...plus its draining power from your lights while running...thats why when you rev it up the lights get brighter.

thenaes

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.

Mikeys03F150

I had a similar problem and it turned out to be a bad fuse...

thenaes

Can you say which one? Ive got the book too, but still having trouble finding this "master fuse" which is supposedly common.

zap

I was going to say, take the battery off while idling. If the truck dies...your issue was with the alt but it sounds like you have found other clues leading to the alt.