I just bought the truck in my sig a couple months ago. The guy I got it from had only put one new Napa Ledgend battery in it, it had the other battery also, and that will be talked about later in the story. I don't drive the truck much and it had sat for a month with out being started in the cold MN winter. Tried starting it and totally dead. Jumped it and would only turn over a couple revolutions, then I noticed the month old napa battery was froze, took that out and replaced it with another used napa ledgend battery (undersized for the truck) I had laying around and it started the truck. Put a AIS intake on it and noticed that the battery on that side is probably the original motorcraft. Drove it a few times with no problems using the undersized napa and original motorcraft until yesterday tried starting it after sat for a couple weeks and only spun over a couple times. Havn't looked into problem yet. Seems strange that the first napa battery would have froze and the original stayed good.

I'm planning on getting two new batteries anyway, but in the meantime is there a way I can test to see if somthing is drawing too much power? I've heard of setting the ohm meter to milliamps and disconnecting the neg battery cable and putting the leads between the neg on the battery and the cable thats disconnected, but what should the milliamps be if everything is ok?

From what I've read is that the sears diehard platinums at $215 a piece is the way to go? I bought normal diehards for my '92 chevy 6.5 diesel 6 years ago and they are still holding up great, and truck doesn't get drove for weeks at a time. Sears the only place that sells diehard?

Thanks.

 

The general rule of thumb for these trucks is to replace the batteries in pairs. Undersized CCA's rated batteries in these trucks is a second no-no. Most likely you don't have a parasitic draw, just you have one weak battery and the other is being drawn down as well when the glow plus are being energized. I think you will be OK with replacing the pair with new ones. I bought a pair of Duralasts and they are holding up well even in sub-zero temps this winter. Good luck.

 

Here's a thread to consider reading:
https://www.ford-trucks.com/forums/9...batteries.html

Pop

 

Just bought me a pair, of big o knarly Kirkland ones, from Costco....75 buks ea.

 

As stated above, Costco batteries at about $150 for the pair are one of the best deals out there. 850 cold cranking amps and a 3 year full replacement warranty.

 

No costco stores in my area, any other stores sell them? Do the batteries themselves say costco?

How about any tips on how to check and see if there is a draw of power? I'm 100 miles from the nearest store that will have a decent battery, so I have nothing but time to troubleshoot a potential problem.

 

It's tedious but one thing you can do is put a multimeter (set to milliamps) on one of the batteries, and take a reading without anything on and no key in the ignition. Then, pull each fuse one at a time, and note if the reading has changed - all still with the key off. Once you see a dip in the reading, see what that fuse powers - Note: there are some fuses that have to be on all the time like the memory for the radio etc. If you pull a fuse that is not suppose to be drawing amps with the key off, then you may have found an open circuit.

Another thing to try is on a cold morning before you start the truck, pop the hood and put your hand on the alternator. It should be stone cold. If it's warm, then it's the culprit and needs replacing.

 

So leave the batteries both hooked up and just put the leads from the multimeter to each of the battery posts?

 

Yes, just leave everything as is under the hood. Hook up your meter to either battery and you will get total capacity of your system. They are wired in parallel to keep the 12v but doubling the amp capacity. This is the reason to replace them as pairs. If one goes bad, the other is taxed to make up the amp difference to supply what the truck needs and therefore it's life is shorten as well. If you just replace one, then you may get caught in the loop of constantly having a battery that is weaker than the other at all times.

 

Tried a test, my multimeter is a small cheap one, not digital, has a needle. Set it at .5 ma DC and it pegged the needle to the right. Set it at 50 and it pegged, set it at 250 and it jumped up a bit and back down to nothing found out the fuse blew, tried again at 250 and blew a second fuse. Everything in the cab off, no key in ignition. Any clues? Thanks

 

You might wanna' read up a little on the internet about how to use a multi-meter before doing this test. There's a mistake in how you are doing it.

Thank goodness you had a fused unit. It prevented some smoke.

Pop

 

where u at i minnesota. check the minnesota chapter maybe some one is close to you and can give you a hand

 

I have been asked to make a correction to the procedure given for determining a constant "current leak" to the batteries. Your original understanding is likely correct, but just to be sure.....

First, be assured that there will ALWAYS be some small current drainage when everything is assumed to be completely off. Things like the station pre-set "keep-alive" memory in the radio.

Set the multi-meter to it's HIGHEST range in the milli-amp scale (or in AMPS if it goes that high) .

Remove the light bulb from the under-hood socket, and close all the doors. If the interior lamp stays on as a courtesy for a period, let it time out and go out. Key position to OFF. Glove box closed.

Next, disconnect the negative battery cables to BOTH batteries, and wrap ONE of them up in a rag to prevent a connection to anything.

Put the negative (usually black) lead on the OTHER battery's disconnected cable, and the positive lead (usually red) on that battery's lead post. If nothing shows on the meter, take one test lead loose and decrease the range of the meter to a lesser full-scale value, and take the reading again.

Continue doing that, one range step at a time, until you are able to read something. How much is it? If negligible, that's normal. If more than that, we'll get into pulling fuses.

But for now, go check it again.

Oh, and yea, where in MN are you at? I'm originally from Aitkin County.

Pop

 

Thanks Pop. I don't like to post mis-information and your clarification is way more thorough than I can be.

Always learning...

 

I am a big believer in keeping a "float charge" on batteries, ESPECIALLY when you have two connected in parallel as in our trucks. In series is not a problem, but in parallel, the weaker one will pull down the stronger one. No two batteries maintain exactly the same voltage at full charge, so one will pull down the other to its level, and sulfation begins on the higher voltage battery. Even just a little bit below full charge will start the sulfation process, so when you let a the truck sit as you said you did for a month, you will have a problem, even if there was no draw on the batteries. Additionally, flooded batteries will self-discharge without use, some say 8 to 40% a month. I think 40% is high, but even 5 to 10% is plenty to start the sulphation process. For the most part, sulphation is not reversable, and destroys your battery's ability to function normally.

I would say, buy two new matched (same brand, same age), and a "smart" charger that will keep a float voltage of around 13.3 volts on BOTH of the batteries. You don't have to spend a lot of money so long as the charger will keep a "float" voltage. Trickle chargers will not put a lot of amps on the batteries, but won't stop charging and will eventually fry the batteries. Smart chargers will sense that the batteries are charged and will cut off until the voltage drops some, then bring back up to the float voltage, as I said before, around 13.3 volts.

Lastly, some will say that you should "equalize" flooded batteries. I am still not sure that our thin plated truck batteries (as opposed to the Deep Cycle type) will withstand the process, but you may want to consider that as well, especially for batteries that sit unused for a while, like a month at a time.