[stlouissux9119]

So I have a 1999 Ford F250 Superduty with 2 batteries. It has the 7.3 of course. I'm having an electrical issue. I have 2 brand new batteries and a brand new alternator but I keep walking out to dead batteries. About a week ago I was driving and I heard a loud "pop" that sounded like it came from down under the dash but I couldn't find anything. After that I hadn't notice anything but then the truck started hesitating starting a little and then this morning it was dead. I have a new alternator and 2 new batteries so i'm confused. Nothing was left on, all lights were off. When I came back to the truck this afternoon there was a clicking coming from the fuse box underneath the dash. I know it had been previously replaced. So i'm basically stuck, I have no idea what it could be.
Any help would be greatly appreciated!
Gahhh seems like i'm fixing or repairing daily

 

[NoRalPh]

Sounds like you have what's called a Parasitic Draw, something is using too much electricity when the truck is off. These things can be tough to find, and drive you crazy! :wink[3]:

Yours seems to be consistent at least, be glad of that, the internment ones will kill ya...

It's detective work really, but you need to prepare to have your batteries dead while doing it (for important times pull Both (+) cables when it sits.)

You can use a mulit-meter inline with a battery terminal in the Amps position to see how much current is being drawn (do this with with one battery disconnected to know the total amount). Shouldn't be much after things "settle-down" as the truck sits (takes awhile for all the electronics to shut down - up to 1/2hr)

You could also start by just taking 1/2 the fuses out of the fusebox and see if that stops it. If not, replace them and take the other 1/2. Then put some back until you narrow down the circuit that has the draw. It's a process.....

 

[stlouissux9119]

So I went to the auto parts store, my alternator was still good. So what i'm wondering is... Now my truck is fully charged. It will probably stay fully charged for a couple of weeks until the battery slowly starts dying again until eventually it wont crank and both are dead. I do have an air ride suspension. If I take a circuit tester (just one of those things that lightup) and disconnect both batteries, and put one end of the circuit tester to the positive of a disconnected battery and one to the positive wire of the truck the light should not come on unless there is amp draw somewhere... correct?
I'm thinking my air-ride suspension is ****ing with me. Damn that thing is a pain in the ***.

 

[NoRalPh]

No, you're always going to have some draw (the PCM & GEM, radio, etc)

I thought, by the way you were talking, that it killed the batteries overnight? You think a full charge will last a "couple of weeks"?

So that's a different thing.... Yes and air pump coming on, because of a leak somewhere, is the kind of thing that could do that. Put a sw on the feed so you can manually control when it runs. Don't let it come on unless the truck is running maybe.

 

[stlouissux9119]

Well I came back to dead batteries this morning again. I'm not too sure of what it could be. When I put one end of circuit tester on the positive terminal of a battery and put the other end on the positive end of the bag draw wire it lights up. I'm not sure. I'm wondering what the loud pop could've been in the electrical system because I think this is all tied together.

 

[NoRalPh]

Again, putting a little bulb between the battery terminal and the cable end (I'm assuming that's what the "bag draw wire" is) is going to light-up for you, it's supposed to...

As for the POP, I guess maybe but usually anything that is electrical and makes a noise like that should be noticeably damaged.

If it IS an overnight thing, put on your "detective hat" and start testing by pulling fuses

 

[jerseyjax]

99 F250 diesel

I am having the same problem with my 99. I was driving along and heard a noise, the truck hesitated and lost power for a few seconds, all the dash lights lit up. I smelled something burning (possibly electrical). I pulled into a lot and got out to check, nothing leaking, nothing smoking, under hood all ok, all lights still working (night time). I continued to my destination only 2 miles away without a problem and turned truck off. Three hours later, the truck started right up but, the battery light stayed on. I drove home without incident. Next day, started right up but, battery light still on. After using truck for short drive the air bag light also came on. When I got home and turned truck off, it was dead, completely. Put charger on batteries and they both charged 100%, and started right up, battery light on, air bag light off. Took it and had alt. tested...it failed so I replaced it with new one. Battery light still on. Took it to have alt and batts tested, could not test alt, said voltage too low in battery. so, took batts out to be tested and charged. Failed. they would charge but were "NO GOOD". Bought 2 brand new batts. and put them in...Battery light STILL on! Took to test alt and batts again...voltage too low to test alt... new batts at 60%. If I charge the batts and let the truck sit, they stay charged but, if I run it, they drain to nothing in about a day. Please Help!

 

[351fifty]

Sounds like a bad alt, you keep going to test it and you can't, just remove it and take it in to be tested or replaced

 

[jerseyjax]

Took it off and had it tested...its good

 

[ChadHowerton]

I am having the same problem with my 99. I was driving along and heard a noise, the truck hesitated and lost power for a few seconds, all the dash lights lit up. I smelled something burning (possibly electrical). I pulled into a lot and got out to check, nothing leaking, nothing smoking, under hood all ok, all lights still working (night time). I continued to my destination only 2 miles away without a problem and turned truck off. Three hours later, the truck started right up but, the battery light stayed on. I drove home without incident. Next day, started right up but, battery light still on. After using truck for short drive the air bag light also came on. When I got home and turned truck off, it was dead, completely. Put charger on batteries and they both charged 100%, and started right up, battery light on, air bag light off. Took it and had alt. tested...it failed so I replaced it with new one. Battery light still on. Took it to have alt and batts tested, could not test alt, said voltage too low in battery. so, took batts out to be tested and charged. Failed. they would charge but were "NO GOOD". Bought 2 brand new batts. and put them in...Battery light STILL on! Took to test alt and batts again...voltage too low to test alt... new batts at 60%. If I charge the batts and let the truck sit, they stay charged but, if I run it, they drain to nothing in about a day. Please Help!

Hey Did you figure the truck out? I am having a similar problem.
Please email me at [email protected] to see if we can help each other out I am an ASE master Mechanic.

Thanks
Chad