Parasitic electric load in modern car turned off and parked?

[hermitjohn]

1994 Ranger.  When I bought it, thought it bit odd to have new alternator and belt, and new but dead battery, but hey has lot miles and it had set with worn out clutch since spring.

Well I have been using good battery from Festiva in it.  Ok if I ran it every few days, but it set week and half and battery dead.  I recharged battery and with negative cable off, connected digital ammeter.  Said 0.429 amp draw.  Put on an old analog ammeter and needle barely budged to discharge side of center line.  Probably wouldnt notice if wasnt looking close.  So half amp is reasonable guess from it too.

This seems kinda high to me, but not high enough to show a serious short.  I pulled the main fuses one by one.  Its some circuit in the interior fuse box, not fuel pump, computer, etc.  I tried pulling fuses on that interior fuse box to further isolate the problem, but it got complicated as the plastic was breaking when I tried pulling some of them, they been in there long time.

Not really wanting to pull negative battery cable everytime after using truck, thinking of using a Ford starter relay mounted on fender like they used to use on older Fords and Dodges.  Run a toggle switch to dash to energize it.  Dont need starter currant to go through it since its an accessory that is eating currant with engine off so just use it to switch off the accessory cable.  Anyway I just run fused circuit directly from battery to energize the relay through the toggle switch.  Turn off the toggle to disconnect the accessories when I turn off the truck.  Any reason this wouldnt work?

[spacecase0]

your solution should work,
things with a computer will get cleared and might not get as good as gas mileage doing that,
so make sure to check how much your fuel mileage changes for the first half tank of gas or so,
just to make sure that it is not to horribly bad.

the leak is likely in some remote door lock device that has long since had the remote door openers broken/lost,
either that or I would look at the memory for the car stereo

my car has a fairly large electrical drain, I unplugged the remote door entry box and it got way better.
have been meaning to wire the memory for the radio to the accessory power wire and not the always on power wire (or put a switch so I can select it), but have not done it yet

[hermitjohn]

Jan 5, 2016 0:45:22 GMT spacecase0 said:

your solution should work,
things with a computer will get cleared and might not get as good as gas mileage doing that,
so make sure to check how much your fuel mileage changes for the first half tank of gas or so,
just to make sure that it is not to horribly bad.

the leak is likely in some remote door lock device that has long since had the remote door openers broken/lost,
either that or I would look at the memory for the car stereo

my car has a fairly large electrical drain, I unplugged the remote door entry box and it got way better.
have been meaning to wire the memory for the radio to the accessory power wire and not the always on power wire (or put a switch so I can select it), but have not done it yet

Has those rare manual roll up windows so doubt it ever had electric door locks.  It lacks year or two of having those stupidly high priced keys for anti-theft system.  In fact it may keep somebody stealing the car, but it steals lot bucks out of consumer pocket when it goes wonky or owner loses the key.  The anti-theft garbage is biggest argument in favor of an aftermarket engine control computer (like mega squirt), cheaper than trying to fix the OEM system if you dont have emissions inspection.  Anymore they dont even test actual tailpipe emissions on current century cars, just plug their test computer in to talk to vehicle computer, thats how VW scammed EPA.  So suppose that means you cant use mega squirt unless you are one heck of a programmer and can do what VW did.  Or set it up so it can run either OEM or mega squirt.

  The radio is history if thats the problem.  I'll just unplug it, assuming wiring harness still plugs in back of car radios.  Its the first properly working radio in vehicle I have owned for long time.  Usually radios are missing or replaced with crappy cheap aftermarket one or just plain broken original.  But I sure dont need it.  Really only like radio on long trip to stay awake, and pretty sure this truck will never be on long trip the rest of its life.  Its pretty much a grocery getter.  No idea why they have to make everything digital/electronic, when analog worked perfectly fine and was a lot simpler.  Right up there with digital control pads on toasters and the like.  Just doing it cause they can, in fact its pure silly window dressing if anybody took the time to think about it half a second. 

[spacecase0]

try unplugging the radio and see if your current drain vanishes
if you still want to keep the radio, but don't want the drain,
just find the 2 power wires to the radio, one will always be on, the other will only be on when the key is on ACC or ON
just cut the always on wire and connect it to the ACC power wire, then it will not hold memories or make any current drain when off
it is a pretty good solution and you can still use the radio to find out road conditions and things like that (if needed)

and if unplugging the radio does not get rid of your current draw,
then it is likely your computer and your original solution is a fantastic one

[hermitjohn]

In the main fuse panel under the hood, the computer has its own main fuse as does the fuel pump, and the accessory fuse box. The drain stopped only when I removed the fuse for the accessory fuse panel. So dont think its the computer. Though obviously the computer would stay powered to maintain its memory. I am not sure why the radio memory would start drawing lot juice, but take your word that they can. Course since thats possible, assume other electronic doodads could start drawing heavily also, though it would have to be something like brake switch that is still on with ignition switch off. And no the brake lights arent on, though was interesting I found the brake light switch unplugged. Not liking to get stopped by cops for stupid things, I did check lights and found brake lights not working, then found switch unplugged. So previous owner maybe was trying to find an electric fault before the clutch went out.

Will first try to find fuse for the radio memory since you say its on constant live circuit. Easier than trying to unplug the radio. Truck came with a brand new Haynes manual. That is now most worthless piece of outhouse wiping paper of a car manual I have ever seen. It doesnt even show fuse locations. If changing fuses is too complicated for its supposed customers, why even bother offering a manual??? Heck even factory owners manual that comes with new car used to have that information. You know that useful booklet telling you where to put gas into the car and where to find the oil dipstick and how to turn on the radio.

ok...

Looks like choices are fuses 1, 4, 8, 10, 12 and 16.... Radio memory is conveniently fuse 1.

[hermitjohn]

Ok, what exactly is an "Amplifier (Electronic Premium Cassette)" on fuse 16?? Radio has a cassette tape player, but why would it have its own fuse? Must be something else. Whatever it is, it is on a constantly live circuit.

[spacecase0]

could be the radio in the car has 2 parts, one the radio, and then separately the amplifier section that goes to the speakers
could also be they labeled the power wire for the memory of the radio and the main power for the radio itself with user unfriendly names

fastest way to figure out what a fuse does is to remove it and see what no longer works,
I test removing fuse 1 and 16 and see what you get

[beowoulf90]

I have a similar problem with my 1999 Dodge Dakota.. Since I 'm no longer using it as my daily driver I found that the battery goes dead after a week or more of sitting. It does have over 270,000 on it, but has always been mechanically sound. Anyway something was draining the battery. I even tried a new battery with no luck.

My solution was to mount a disconnect switch to the negative side of the battery. It can be a pain since I have to open the hood when I want to use it, but it has worked. I don't have the time or motivation to go searching for what is draining it..
But then I think I will be looking to replace it in another year or so, because the body is getting to the point that I can't keep repairing it. I hate the thought of having to replace both front fenders.. Which up to this point I haven't been able to find for a reasonable price yet.. everyone wants an arm and a leg for used rusty parts.. I guess I will throw another piece of sheet metal in and putty and primer it..

I've already replaced the rocker panels with pieces of stainless steel from commercial kitchen equipment that I was scrapping at the time.. So they won't rust for a while...

Hardest part was getting the contours right with only ballpeen hammers and an anvil.. But it works, just takes longer..

[allenw]

I've had trouble with a glove box not shuttimg right and alloweing the light to stay on.

[hermitjohn]

Well went to town today and figured out why the previous owner left the brake light switch unplugged. I got out of the truck at TSC and my brake lights were on, nothing I did made them cease and desist, so had to unplug the switch. Less chance getting stopped with no brake lights than with them on all the time. Need to replace the switch.

[hermitjohn]

Chilly day but finally went out and pulled fuses. Pulling fuse 1 brought parasitic load down to 0.3A. Pulling fuse 10 brought it down to 0.16A. Other fuses had no effect. 0.16A still seems higher than I would like, but lot less than it was. Probably could set up to three or four weeks without battery going dead.

I suppose if I wanted it absolute zero, could use a starter relay to disconnect/connect whole negative battery cable. Might be way to go. I havent driven the truck enough to get real accurate sense of fuel mileage. Just from trip odometer and gas gauge, its around 20mpg, which is ok for a V6 in a 4000 pound vehicle.

I still am not sure best strategy to deal with the wonky transmission. It works but is noisy enough that it doesnt inspire lot confidence. Being that noisy with mostly Lucas in it really makes one scratch the ole noggin.

Far as putting a granny four speed into it (and I'd really like to do this), almost as cheap to just use a Chevy 4.3L converted to carburetor. They are one of the more modern engines still pretty easy to retrofit to carb and have the traditional SBC bolt pattern, making them very easy to use with older transmissions. Eliminate all the computer engine controls.

I already have three spare granny transmissions for a chevy. Couple of them downright ancient still have a hand brake attached. Keeping the Ford 4.0L means buying an expensive rare bellhousing and buying a granny four speed out of a Ford. Hoping it all fits together. Then dealing with the engine control electrical gremlins as they show up, and at this mileage, they will. Already noticed some intermittant weird idling symptoms with engine hot. Shame as I sort of grown to like the 4.0L. Enough power and 20mpg. But no doubt a 4.3L with 2bbl carb would do the same and whole lot simpler to maintain long term in a high mile vehicle.