Join Our Ford Truck Forum Today

Document your Ford truck project here and inspire others! Login/Register to view the site with fewer ads.

Battery draw...

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
This is something I've never really concerned myself with, but have always wondered. Red and the Bronco sit alot, but I fire them up every week or so to keep the fluids flowing and whatnot. That said...they don't always get started weekly...and I've noticed I can turn accessories on and roll the window up and down in the Bronco all month without actually starting it...and when I finally do start it, it'll fire right up...no questions asked. Also note, the Bronco was completely rewired by my father and myself when I bought. Red on the other hand, can sit for a few days/week and be dead as a door nail when I go to start it. I haven't noticed any draw at the battery or fuse box. The wiring is about as original as you can get except for a couple sockets. Both rigs have the same alternator and battery. Like I said, I've never really concerned myself with this, because I usually drove them often enough not to notice, but since bother have been sitting for a while...I've noticed the difference. Any suggestions as to what's going on?
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
Haven't checked the 'production dates' on the batteies themselves yet...but they were purchased about 9 months apart. I wondering if there isn't issue somewhere with the alternator because Red has been notorious for eating them. If I'm not showing a draw, could this be viable, ie the alt not giving a full charge to the battery when running? If so, where/what do I start checking?
 

Fellro

Moderator
Staff member
what do you have for a sound system? It could be a regulator/wiring issue, the connection at the regulator is notorious for issues.
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
If its eating alternators that means ya got. A wiring issue. Somewhere is drawing power.

If I had a draw, would that not show up at the battery with the negative cable off and/or at the fuse box???

what do you have for a sound system? It could be a regulator/wiring issue, the connection at the regulator is notorious for issues.

Sound system is just a standard sony xplod head unit with matching 6.5" speakers. Regulator could possibly be a potential candidate...in 10 years, it's never been replaced.
 

Jolly Green

I Salt My Ketchup
Do you have any optional or DIY add-on lights under the hood or in the glove box that are staying on, but not easily visible?

Anything plugged into the cigar lighter while is sits?
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
Do you have any optional or DIY add-on lights under the hood or in the glove box that are staying on, but not easily visible?

Anything plugged into the cigar lighter while is sits?

No DIY, but Red does have the glovebox and courtesy under dash lighting. The lighter is actually disconnected at this time.
 

dakonthemountain

California Chapter member
Ben, In my RV's there is always some electronic memory somewhere draining the battery. Does you Sony have a clock?.. Perhaps the combination of the battery being low and the memory from your stereo could be drawing it down more each time. Remember, after so many times being drawn dead your battery really starts to loose efficiency. Try switching batteries with the Bronc and see if it still happens. Good luck! (oh, and please buy my truck. ;-) :)

Dak
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
Ben, In my RV's there is always some electronic memory somewhere draining the battery. Does you Sony have a clock?.. Perhaps the combination of the battery being low and the memory from your stereo could be drawing it down more each time. Remember, after so many times being drawn dead your battery really starts to loose efficiency. Try switching batteries with the Bronc and see if it still happens. Good luck!

Another good point...the radio does have a clock, whereas the Bronco does not have clock. And I was getting curious about the battery charge myself...seeing as it's been run to empty several times and no real time to charge...maybe that's the deal. But in the last 9 months, the Bronco has gotten about the same attention.

(oh, and please buy my truck. ;-) :)

Dak

I would love to have your truck...but unless you're willing to take a serious hit and maybe some belly button lint...I doubt it could happen.
 
Get your analog meter out ;) and set to ohms scale, blow on the glass or
plastic cover to discharge the static, zero it, then read the resistance to
ground from the disconnected positive battery cable clamp.

Infinite ohms is what you should be getting. :)

-----------------------------

My son just went through this getting the '75 F250 "farm Truck" going.

It had two grounds in the system...
1) the aftermarket -no-name- electronic voltage regulator
2) the rubber boot in the harness behind the alternator was grounded inside

He cut that boot off and re-wired it from scratch and took my Echlin voltage
regulator off my '75 F150 and it was fixed... except for one thing, he killed
my really old battery out of my pickup in the process. It being run dead a
couple nights in a row did it in. LOL :)

He compared the resistances on the replacement alternator I had ready to
go (new bearings and brushes) with his and they read the same.

---------------------

You can do it and not waste 1 cent on the wrong new parts if you work at
it with a meter.

How ya gonna go about it, Ben? ;)

Alvin in AZ
 
Last edited:
These wet cell batteries need to be CONSTANTLY used-discharged-recharged or they will sulfate in the case and go bad.
 

BuzzGun79

Nov.TOTM 2012 / 2012 TOTY
2,388
55
Ben,1 do you get an arc when you hook up the neg cable? the regulators are prone to draw it down & fairly inexpensive to replace.about 20 bucks if its over several years old for the money replace it,its cheap insurance.also check the alt.belt for proper tension & wear a loose or deteriating belt & it will not charge properly.

2 battery age,it may be going south,do a draw test on it,if the battery is not a sealed unit remove the caps & check water level fill to the bottom ring of each cell,weather its maintenance free or not,[a dry cell is an indication of an overcharge which is a regulator issue}unhook coil wire,turn on headlights,crank the motor at the selenoid with a screwdriver or remote starter switch,when it goes dead keep cranking & inspect all cells of the battery they should start to bubble[use caution while doing this & wear them saftey glasses or better a face sheild} if they dont its the battery.if the battery is sealed well its pretty much a guessing game as far as the battery goes & i usually go by age of the battery.

3 a simple proceedure to see if its charging,[if you dont have a volt meter} start the truck & remove the negative cable off the battery,if the truck continues to run the alternator is working correctly.if it stalls replace the regulator first,then if it still stalls the alternator.be sure to check all connections at the reg these plugs are also prone to fail.check the pigtail coming from the alternator to the reg, ive also run into trouble with these wires on these rigs{i dought it tho on your truck due to the condition of the truck & you probably keep it out of bad weather ,she's a beauty might i add}a volt meter hooked up to the battery while running should read approx.13.8 volts anything less than that is a discharge condition.

the clock could cause this if the battery is an older unit & not regenerating as a newer one would.
 
Last edited:

BuzzGun79

Nov.TOTM 2012 / 2012 TOTY
2,388
55
unless you have had wiring prolblems in the past,i dought if its in the harness,my 79 came from Arizona & from the fading of the seat & cracking of the rear view mirror plastic,she got pretty warm in there at times & i have no wiring issues.its all original,but you never know.
 

BuzzGun79

Nov.TOTM 2012 / 2012 TOTY
2,388
55
Ben, get a Battery Tender for when you store your vehicles.if memory serves me correctly they make a unit for multiple batteries.they keep the battery from running down & shut off automatic when the battery is charged & extend battery life,got one on the wifes Honda 750 & soon will have one on the 79 truck since it will be stored also.just hook em up & plug it in & forget it.just to be safe i remove the ground cable off the battery during storage.they are a good investment.God i hate winter..lol
 
Last edited:
I have had this problem with a 77 that sat more than it was driven. The radio had a wire that was always hot to maintain the chanel memory and the clock. I unhooked that wire and it quit draining the battery. I just had to retune the radio when I wanted to use it. Something easy to try before digging deep.
 

LEB Ben

Arrogant A-hole At-Large
34,919
1,124
outside your house
Thanks for the suggestions fellas. Gonna see if I can't track this down over the coming weeks.
 
Each cell can be tested to see if there is a bad one. Use a volt meter with negitive to ground post and positive to the acid in each cell. Should read in increments of 2, up to 12 minimum.
 
Top