2nd Gen Non-Engine/Transmission key off current draw

[Ncostello]

I found that my 99 draws 0. 38 amps just sitting there in the garage. I hooked up the multimeter in series to the + post and the positive cable. I only had the drivers side battery in when I did this. I've had a few battery problems as posted in 911. I very recently installed two new batteries (Napa 75 Legend), let the truck sit for 4 days in a cold garage and it would not start. Both were drawn down to 11. 7 volts. I was able to finally get one to charge and stay around 12. 5. The other likes to go back down below 12 on its own. Both were charged separately out of the truck.



Anyway, is this consistent with the 24V trucks since they have the computer systems etc? Should it draw less? Thanks.

 

[LSMITH]

My truck is a 99 too, and has sat for over two weeks without a problem. Started like I had just gotten out of it. . 38 amps is a LOT, especially when the only power needed is for the clock, radio presets memory, ECM and PCM memory and security system if you have it. There might be a couple other drains, but they should be very small as well. Just a guess with NO data to back it up, but you should be looking for . 05 amps or so max for key off drain. Something is draining your batteries. Start pulling fuses and circuit breakers to find what circuit the drain is in.

 

[Ncostello]

Looks like my multimeter christmas gift was just in time!



Tractorface warned me about this over in the 911 forum. Looks like you may have been right sir. This draw must have drained them... and in the meantime ruined one in the cold, unless the situation was more complex than I first thought (bad battery to begin with and excessive current draw). Either way, one is gone for good now.



Meantime, I'll start pullin fuses and narrow this down hopefully. I'll check the main battery positive connections and grounds too.

 

[Gary - K7GLD]

UMMmmmm - you DID remember to disconnect the underhood light when ya took that reading.....



AND, don't give up on that "bad" battery - often, several charging cycles WILL bring them back to lfe - at least enough to use as backup or jump-start service for other vehicles - I usually have a couple around like that I keep charged up and ready to go...

 

[illflem]

I've was surprised at the size of the spark when connecting my Optimas up, key off, no underhood light, yet it's started right up after sitting for three weeks though it was a little slow. My '95 manual says that the batteries should be charged, the truck driven at least every 20 days or the batteries disconnected to keep the charge up.



The way the manual recommends testing IOD (ignition off draw) is to use a test lamp instead of an ampmeter but connect it the same way you've been doing. At the normal draw the light will be very dim, if it's bright you've got a problem. This makes it into a one person operation without running back and forth to the meter.



My '95 take 20 milliamps to run the pcm, clock, etc with the ignition off, 24 valve is probably more. Key must be removed for at least 3 minutes before preforming the test, hood lamp removed, doors closed. When you go to check the inside fuses hold the door switch down and wait 3 minutes before further testing. Along with faulty wiring/switches that is traced by removing fuses they say an internal generator short may cause higher readings, you have to disconnect it to isolate a drain there. Good luck.

 

[Ncostello]

Thanks all...



I took out the hood light along time ago so its not the source but thanks for the tips. I did however install the battery for this test and immediately tested the draw. Maybe I should let it settle for 5 minutes then take a reading.



I'll duct tape down the door switch so it wont affect anything too. Thanks for the tips. I'll keep trying and find the cause eventually.



I have to take that bad one back Gary. Its only a month old and was $85. They finally agreed to take it back.



I didn't know but I could have bought Interstate Megatrons through work at the maintenance shop for $50 each. They were more CCA's, RC, CA and had removable tops. :{ Boy do I feel stupid for that one.



For some dumb reason, I didn't check the tops of these NAPA 75 Legends. They appeared removable like all the other Napa batteries I have owned but I later found out they were not. Now I cant check the level or electrolyte strength. ARGGGHHH!! Never again... never.

 

[jeepit]

I am not using my truck this winter except to plow my own driveway. If I hook up a trickle charger, which battery should it be hooked up to?

 

[Gordon Maney]

Ignoring the specifics of your situation, a key off current draw can easily be caused by a leaky diode in an alternator.



If pulling fuses is of no help, disconnect the battery lead to the alternator and see if it affects it. Before you do that, however, disconnect the ground leads to your batteries so you don't weld your wrench to something and burn your hand severely.



Your draw amount, taken literally, seems quite high.

 

[Ncostello]

Jeepit:



I would hook to the drivers side... however it really shouldnt matter. Are you using a 1A or 2A trickle? I'd like to get a smart charger that senses load and adjusts on-off accordingly to prevent overcharge. Maybe you could get a simple 120V timer plug so the charger only charges maybe 2-3 hours a day.



I'll check the alternator too. I was supposed to get today off but got called into work anyway. Just like I did on my vacation too. I'll leave here in a while and get to have some fun workin on the truck.

 

[Gary - K7GLD]

"I am not using my truck this winter except to plow my own driveway. If I hook up a trickle charger, which battery should it be hooked up to?"



The batteries are connected in parallel - when you connect to one, you charge both at the same time...

 

[jeepit]

ncostello, I have the charger hooked up to my off road Jeep. I will check what amp it is when I get a chance to get in the barn later. Later tomorrow I just may start the truck up and run it around the yard a bit.

 

[Ncostello]

Don't know if I actually solved the problem... but I'd say there is a good chance I have . With the help of TDR of course!!



I disconnected the alternator and it still kept drawing 0. 45 amps. I noted that it was now drawing more than it did yesterday... which was 0. 38 amps. Anyway... no dice there.



So I started pullin fuses and relays... and fuses and relays and so on. But none of that helped. In fact the more I did this the more power it seemed to use. It went up to 0. 49 amps near the end.



I finally solved the problem with my ears instead of the ampmeter. Now I live on a somewhat busy street and there are lots of cars passing by making noise. But for one breif instant while it was quiet, I connected the ampmeter again and heard a faint click inside the cab. So I had my neighbor come over to the garage and connect the ampmeter while I sat in the cab. It turned out the noise was coming from the front seats (both)... more specifically the seat belt mechanism in the front seats (Quad Cab). I unplugged them underneath the seat and voila... no more 0. 49 amp draw. Now its just 14. 5 mA.



PS: The only fuse under the hood that stoped the draw was the 50A battery fuse. The only fuse in the dash that stopped the draw was the I. O. D fuse with the black clip thing around it. I fugured these were fundamental fuses somehow cause both caused the ampmeter to show 0. 00... and I know there has to be a little draw somewhere.



Any ideas on what I did? And is it dangerous for me to leave the seatbelts unplugged? At least I think I found the problem.

 

[Ncostello]

Well, my victory was a little short lived. Turns out that by unpluging the plugs under the seat solved the nearly 0. 5 Amp draw. But in doing so, I could not get my seat belts to come out of the seat... as if they were locked. Plus my little red guy on the dash wouldn't go out.



What the heck do those wires do anyway... and why would they lock my seat belts up if unplugged? Maybe I need new sensors. But getting to them in the seat dont sound like fun. I tried unplugging the "seat belt 10A fuse" but that didn't do anything to stop the amp draw while he key was off. Hmmm... back to the drawing board. At least I found the problem I think.



Again with the seatbelts plugged in under the seat... . 0. 49 Amp draw. Seatbelts unplugged under the seat... 14. 5 mA draw. Twin batteries would last for a long time only drawing 14. 5 mA. But at 0. 49 Amp, they only last 3-4 days in the cold.



Anyone got any ideas what I should buy next?:{

 

[warlock36]

This doesnt solve your problem but there is a battery minders that hooks up to your car and shuts off the circuit if your bat gets below a set point. They are used on police cars and fire truck due to the high draw of flashlights, radios and the such when ther are not running. Might check with an autoparts store or police/fire supply store.

 

[Ncostello]

Maybe a dead end again

Is there an award for the most posts to ones own self?



I searched under "IOD" or ignition off draw and found some info that directly may apply to my situation.



Crowhurst (I think) posted some info from the Service Manual on testing IOD. Appears that the seatbelt retractor switches will pull current for 30 minutes thus showing a draw of 400mA (or . 40 Amps as I reported) then after 30 min the draw would reduce to around 25 mA. So upon initial connection of my ampmeter, I need to leave it on for at least 30 minutes and see what draw I have then. If it goes for longer, I may have bad switches in them thar seats. Hope this applies to 99 seats as his was a 98.



So now I have to disconnect the batteries again I'm gettin too used to doing this!! Gonna wear out my battery cables.

 

[illflem]

All this to find out you had a bad battery?

 

[Ncostello]

Today I disconnected the pass. side battery (again) to isolate the power supply to the drivers side only.



Then I took the ampmeter, held one probe to the positive post (drivers side) and the other was held to the positive cable. Then I carefully lifted the cable connector off the positive post so as to not disrupt the power supply. In doing so I am still drawing . 40 amps (400 mA) after the truck has been sitting all night. If the service manual was right, the seat belt retraction mechanisms should draw 400 mA for 30 minutes, then stop drawing power. The power draw should then only be 14-20 mA.



Yesterday I was getting high readings from the seat belt retractors because I was not letting them settle for 30 min. But today they had been sitting for 12 hours and were still drawing power from the batteries.



So at least I was able to determine the seat belt retractors are not "operating" properly. And I cant unplug them cause then my little red light wont go out and I cant pull the belts out of the seat. So I need to see if Dodge has any suggestions.



What does the "seat belt" fuse in the dash do anyway?? It didn't cut power to the retractors.

 

[Gene Heck]

NCostello,



Listen to what illflem just said. It may not be your problem, but it is the best place to start. Often when you have multiple batteries one battery will start to crap out and drag the others down with it. It doesn't matter that they are almost new. Don't be afraid to take the batteries back to the dealer that you got them from and have them do a load test on them. From reading your posts it states your amp draw is from 38 ma to 49 ma. That is very high as we all know. Are you taking your reading after both batteries? If its's not practical to have the batteries load tested, you might consider leaving only the good battery hooked up to eliminate the one that falls off in voltage most. If it's not to cold there right now, and you really don't need your heaters, try running like that for a few days to see if the problem goes away. If it does you probably have a bad battery like Bill suggested. If that fails check your alternator for bad diodes. Good luck!



Gene

 

[Ncostello]

Gene, I understand and appreciate what illflem has said however bad battery(s) is a result of an electrical problem... I have to fix the problem or any battery will suffer the same fate. I did have them load tested too. I'm doing all my tests with a single battery thats good at 12. 5volts. But my problem deals with amp draw no matter what the voltage of the battery is... as long as its close to 12V.



You may have misread my posts (assuming I didn't make any typos). My draw is 0. 4 Amps... which is equal to 400 mA... which is also too much ignition off draw. That amount of key off draw is killing what ever kind of battery I put in there. Just like a 0. 4 Amp light bulb burning all the time.



You typed 38 to 49 mA. I would like to have that little of a draw. Thats what I am after. Remember 1 mA = 1/1000th of an Amp.



Ignoring anything about my own batteries... consider if I placed one brand new battery in my truck that was known to be a good battery. If you then took an ampmeter in series with the positive wire, the reading would show 0. 40 full amps... not mA. That is too much. The brand new battery would soon be discharged just the same as any battery would. It may even be ruined if its highly discharged in extreme cold weather.



I know what the problem is. I've pulled all fuses and disconnected the alternator... and through a process of elimination I have found the gadget(s) on the retractor mechanisms of my front seat belts are what is drawing the big amps here. If I unplug the units under my front seats, my amp draw is 14-15 mA (milliamps) which is more like what it should be. Any battery would last a long time at that discharge rate. No other thing I do except for this gets rid of my high Ignition Off Draw. Even after 30 min, I still draw 0. 40 amps. This should not be.



Now the story becomes more complicated because you have to give those gadgets 30 minutes after initial battery installation (connection) to stop drawing 0. 4 Amps. According to an archive post by Crowhurst, after 30 minutes the service manual says they will stop drawing power and the only draw you should have is for the ECM, PCM, clock etc... . and that will read somewhere in the 10-20 mA range. At least thats what I read and my service manual wont arrive in the mail for a couple more days.



My retractors (one or the other or both) never quits pullin power. And I cant just leave them unplugged cause my seat belts wont pull out... they lock up. So its either replace these things or keep replacing, recharging etc the batteries. I dont even know how to get to them to check them... they are inside the seats (quad cab front seats).



Sorry I'm so long winded... I'm just trying to make sure you see my problem.

 

[Gary - K7GLD]

No problem here - you have explained it perfectly, and I understand the ma values you quote as well - dunno WHERE those "other" values came from...



I'm like you, and don't quite understand what the long-draw is on the seat belt assembly with the ignition OFF... OR what the purpose of "lock up" is when ya defeated them...