I am looking for some idea's before I take my 98 4.6 F150 to the dealer.
This will be the second winter I have had my truck and after spending all of last year trying to fix this problem, I am going to take it to the dealer, unless someone can shed some light on my issue.
When the temps start to drop into the teens over night, my battery dies. It's easily jumped with little to no charging time. Last year I put in a new battery and new lugs on the cable ends. During the summer months, i have no problems with the battery.
Thanks in advance for any suggestions,
Paul

 

Make sure all your connections are good, tight and clean at the battery, starter and relay. Also check the starter cables along it's length to make sure it doesn't have a bad spot where it might have been rubbed or poked. If it looks swollen in a spot it may have corrosion inside causing just enough resistance when it's cold to not get enough juice to the starter.
If all that checks out then look for a parasitic voltage draw when the key is off. Best way is to unhook one of the cables then take a voltmeter and hook one end to the battery post and the other end to the cable you unhooked. Have it set to dc/v and see what it reads. You can do the same with a 12v test light but if it's not a big draw it may not light up.

 

You don't use a voltmeter to measure current flow.
Use the Current function, but be sure the current is not more than the meter will read or it's fuse will blow and or damage the meter movement.
The lamp test is good to get an idea of what the drain is before hooking the current meter function in series.
A small lamp that just begins to light indicates current less than about 2 amps.
A 5 amp meter range will handle this fine.
A large lamp that just lights, indicates several amps drain.
Be sure to remove the hood lamp from it's socket or you will measure it's drain.

 

avcdo/paul, I'm new to this site and just seen your post and want to tell you that i have exactly the same problem when the cold weather sets in. 2 years ago i installed a disconnect switch on the battery and now i can let the truck set for weeks without a problem starting it once i turn the switch back on but now it's getting on my nerves having pop the hood every time to disconnect and reconnect the battery now being it draws very fast sometimes. If anybody out there gives you a clue what could be causing it PLEASE let me know and i'll do the same. Thank you in advance, quigley

 

I'm new to this site and just seen the post about dead battery in cold weather and want to tell you that i have exactly the same problem when the cold weather sets in. 2 years ago i installed a disconnect switch on the battery and now i can let the truck set for weeks without a problem starting it once i turn the switch back on but now it's getting on my nerves having pop the hood every time to disconnect and reconnect the battery now being it draws very fast sometimes. If anybody out there has a clue what could be causing it PLEASE let me know. Thank you in advance, quigley

 

You have an excessive drain on the battery.
What have you done to find it?
Replacing the battery and terminal won't stop the drain.
The Alternator can be a cause from leaky Diodes or the Regulator allowing the field winding to draw current.
Some other circuit in the truck drawing current.
Cold weather will always cause reduced battery capacity if not kept charged.
.
At least put a meter in series with the positive lead and measure the draw to get a lead on the amount then pull fuses one at a time until it drops..
The only draw you 'should see' is what the computer takes to keep memory alive.
On a good battery fully charged, it should stay up for a couple months just setting.

 

bluegrass, I've owned the truck almost 5 years now and it's been doing it since the first cold spell.
"unfortunately i bought the truck in the summer time so i didn't see the problem when i bought it"
we tested everything we can think of at the time including replacing the battery with no luck and that's when i put a battery switch under the hood and it works great but, as i stated before, i'm getting tired of always having to switch off and on.
At that time we found a video on you tube saying it was a cold solder in the cluster that could be fixed myself if i wanted to tempt it but i can't find that video anymore and really not sure i would tempt it but just met a new neighbor that solders a lot if i wanted him to tempt it.
when it gets real cold out, i'll loose the odometer reading to till spring time.
Up until this year rock auto had them for sale but their out of stock till who knows when and a friend tells me that might not fix the problem and told me to come on this site for advice.

 

The soldering will fix that, but not the drain. Read this thread:

https://www.f150online.com/forums/ar...r-99-03-a.html

 

I described what has to be done in my first reply.
You have a Drain that can be isolated by removing each fuse one at a time while the Current meter is observed..
How much current is flowing in the drain?
Is the Alternator housing warm the next time you go to start the motor from cold?
Removing the heavy lead to the Alternator; did this stop the drain?
Pull the plug on the Alternator, did this stop the drain?
These observations are important to note.
This will point to the circuit that is your fault.
Look up the fuse assignment that loses the drain when the fuse is pulled.
On some circuits there are many parts that can be at fault.
The Glove box light for instance. You never know if it is still on when the door is closed.
Troubleshooting on your issue was just not good enough no matter how you feel about this.
Good luck.

 

I want to thank everyone for your help. i'm still working on it step by step because as i mentioned before that it only happens when it get cold so last weeks warm spell didn't help my cause.
I DO WANT TO MENTION SOMETHING I FORGOT BUT NOT SURE IF IT MEANS ANYTHING.
as i mentioned, i have a disconnect switch on the battery so when i do turn on the switch THE HORN BLOWS !!! does that mean anything ????