2000f350 dually wont start [HELP HELP]

[bevansracing]

HELP,,,, 7 months ago i replaced my alt. and both batteries . About six weeks ago it wouldnt start one morning, took both batteries to be checked and alt. also and all three were fine.My buddy suspected the truck had a overnight drain but we could never find it.Fast forward till noww and have been disconnecting both batts every night,NOT MUCH FUN! well we put an amp gauge between cables and lo and behold a 1 1/2 amp drain so we started searching and found that when you disconnected the alt. it went away.Left alt. dissconnected over night and both batterys connected and truck started fine. Well replaced alt. wed. night and this morning it wouldnt start so my buddy started checking and we believe the new alt. is bad so we replaced it again . hope it starts in morning,,,,,any thoughts anyone

[bevansracing]

well we put on a 3rd alt. and two new batteries and has started fine this morning in 39 degree temp,has anybody ever heard of a alt. sucking power when off

[pipelayerjdh]

I have seen it when the voltage regulator goes out.

[bevansracing]

Is trere something in the truck that could be blowing the voltage regulator

[Ditty]

Where are you buying the ALT's at? If you getting it at an AutoZone, ETC, you might want to just take your's back now, cowboy up and buy one from the dealer. Aftermarket/rebuild items like Alt's, starters, etc are known to be "not as good" as the direct factory replacement items. (Note: same goes for brake pads!) I bought an ALT from Advanced Auto a few months back b/c my Alt died, Fast Forward to today...I've had my battery light on almost constantly since. I checked the voltage while running and it hovers around 12.5V all of the time. It's just enough to power most of my accessories and keep the batteries with enough charge to start the truck.

[bevansracing]

not sure where my buddie gets them from but if this keeps up i will make him get one at ford ,,the first one had a 1 1/2 amp draw and the second had a 4 amp drain

[bevansracing]

Well we put another alt. on and two new batts ans the truck sat for 15hrs and woulkdnt start again and am having to charge up my new batts ,,,,, anybody have any ideas

[stroker27]

u can get an alt. with a warranty without going to the dealer...and you can get lifetime warranty brake pads too. its not likely a series of bad alt. find whats shorting it out. do you have aftermarket accessories that could be shorting it when you use it?

[straycat]

Any updates on the problem/cure?. Did you get it figured out.

Gord.

[bevansracing]

gord, we put a new in box alt and it has started every morning so far including today with a temp of 27 which for houston is cold ,,,, i guess i got 5 bad alts.

4rebuilt alts from rebuilder
1 ford rebuilt alt
2 new interstate batts
1NEW in box FORD ALT