Archived Battery drain with ignition off!

[JCook1]

Hello all that wish to partisipate in this discussion.



I have a 1997 Dodge 2500 auto 2wd.



My problem is that if I do not turn off all switches in the cab before turning off the ignition switch I will have dead bateries in the morning.



I have tracked all of the things that I know how to check but I was hoping for some help before going to the Stealer (Dealer).



This has been an ongoing problem for close to a year and I have about given up on it as it causes no problem if you turn everything off first.

The problem is that no matter how many times I tell my wife the procedure for this vehical she forgets and I am stranded or late to work.



Any and all suggestions will be appreciated and checked.



This is not the map light or many of the other problems discussed that I have read as it has happened for close to a year and in all kinds of weather.

The heater grids were my original suspect because of all the problems reported with them but in the summer they don't even come on.





Please help Guys and Gals.



JCook1

 

[LSMITH]

What are the things you turn off and do not get dead bateries in the morning? If that does not give us an info you need to do some more troubleshooting.

Do you have an amp meter? If you have the tools this should be relatively easy to find. With the door closed and key out with the truck off there should be only the radio and possibly the ECM drawing power. Both will be miniscule amounts of power. Either connect your amp meter in series with the battery positive lead if it is the inline type or clamp the probe around the battery positive lead, you should be showing no current draw. If you do show a draw start pulling fuses one at a time. If the draw does not go away put the fuse back and pull the next one. You will find the draw with one of the fuses. If you connect the meter and see no draw start turning things on one at a time in the cab of the truck, whatever you noticed will keep the battery from discharging when it is off. Now to figure out what is on that circuit and why it is drawing power when it should not will depend a lot on what circuit it is. Let us know what circuit it is in and we can go from there.

 

[JCook1]

Items turned off.

I turn off the AC or Heat depending on the season, the fan switch, Radio and all the interior light switches. They are seldom turned on but I make sure that the switches are off. If the AC - Heater switch or the radio is on when you turn the ignition off then you had better have jumper cables in the morning.

 

[LSMITH]

Does the fan stay running or the radio play if you do not shut them off? For the heater the valve that selects inside or outside air is electric, the AC clutch is electric, and the blower motor. Those are the major things I can think of off the top of my head. Does the radio diplay stay on? Just a few ideas.

 

[JCook1]

Answers to ideas thus far.

Radio does not have display with ignition off.

Fan does not run with ignition off.

AC clutch is not engauged with ignition switch off.

Don't know about the air circulation servos.

Do you know how to test current flow through that circuit?

 

[illflem]

If you don't have an ampmeter you can tell which circuit is drawing power with the key off by removing the fuses one by one. When you reinsert one that is pulling juice you will usually see a spark. Doing this in the shade/night rather than full sun works best.

 

[JCook1]

Ampmeter?

I have several multi meters. I do not have a clamp on DC ampmeter. Can a analog multimeter be used to determine the source of the problem?

The ones I own only go up to 10 amps DC and I am not sure of the current draw at this time. I am not ready to loose even a radio shack meter for this. Please advise the procedure for deteminig the draw if it only happens when the key is on and something is drawing current before the key is turned off. I am willing to purchase a clamp on DC amp meter. I would appreciate any suggestions for an inexpensive one though. I do not use them often enough to justify the cost of a Fluke. I have owned them in the past and they are wonderful pieces of equpment but the trip to the stealer would probably be cheeper than a Fluke meter.



Thanks for the input thus far.



JCook1

 

[redramnc]

For parasitic current draws 10A is more than sufficient. Start with everything off and key off, then leave key off and start turning stuff on until the meter starts showing draw. The radio and ECM keep-alive combined should be well under 1/2 amp so your 10A meter should find your problem. Just make sure you are on the 10A setting and not the 40mA. The keepalives you can look for with the 40mA as they shouldn't peg the meter. When you find the offending circuit, combined with the keepalive draw, it should be well over what the 40mA circuitry can handle.



From experience I have found that radios and ECM keepalive power will kill a battery in around 15 days if the car is not started. This has happened to several people I know - let a Dodge Shadow sit for 2 weeks and the battery cannot start the car. Since diesels require a bunch of juice to turn them even a slightly diminished battery may have troubles.



For yours to go down overnight there is probably a 1A or better draw. Good luck finding it.

 

[LSMITH]

What you need to do if you use the meter you have is wire the leads in SERIES with the positive battery cable. Hook one lead to the battery and the other lead to the disconnected positive lead. Your meters, even the radio shack meters are fuse protected, no worries about smoking the meter as long as the scale is set right. Clamp on probes just clamp over the positive lead.

 

[JCook1]

Help my understanding

I don't know if I am not explaining this right or you nice folks are not understanding my explanation.



The problem only occurs when the engine is running and the accessories (particulaly the climate control ie AC or heater) are running before shutting the key off. It cannot be duplicated by turning these things on after the truck is turned off.



Since we have two batteries I guess I can remove the positive terminal from one battery and connect the meter in series while the engine is running. Then turn the key off, remove the other positive terminal from the remaining battery.



This would keep the meter out of the voltage and amperage surge from the alternator when removing the terminals. It would also keep the circuit alive for testing purposes.



I keep forgetting about the two batteries in our vehicals. They can sometimes be a godsend.



I will try this approach tonight if I can come up with a way to isolate the cable terminal ends while I run back and forth from the cab to the engine compartment.



If in fact the circuit cincerned is the climate control in the truck and the draw is not the AC clutch, any sugestions as to where to look?



Thanks for all the replies.



JCook1

 

[redramnc]

Not a good idea to unhook battery cables while running - voltage spike of the arc can take out the regulator.



You are correct, I didn't understand the problem condition.



Sounds like a relay is sticking on even when the key goes off.



Very unusual problem - don't know how I would troubleshoot it unless I had it in front of me and could let my mad scientist troubleshooting brain wander around at will and try whatever came to mind (mostly blank).



OK - try this. Make sure the meter is in the 10A mode. To get the leads in series turn the key off. Put one lead on battery post and other on terminal end. Pull terminal off of post, keeping both leads connected (will have to slide terminal up the lead going to post to disconnect). This will keep current path to keep whatever is energized going while the meter ends up in series between the battery and the cable.



Then start looking for offending circuit by pulling fuses and watching the meter for a significant drop in amps.

 

[Joe G.]

JCook1,



The batteries are connected in parallel so they are just like one big battery. If you disconnect one the other assumes the load. So I don't think that will work to measure current draw.

 

[Missouri Mule]

Seems to me you have insulation (plastic) worn off a wire(s) maybe a bad connector.

I would think a power and ground wire from two different sources.

One of them could be ignition related. The other a/c(heater) and/or radio.

I believe the term is welding of wires (or grounding out).



If a/c(heater) or radio is in the on positon

(recieving or sending power to a component that is related),

when Ignition is turned off battery will drain (lose power).



If the above components are turned off before igniton is turned off no battery drain.



Apparently when a/c and radio are turned off the weld is broken.

I would think that these components are the power part of weld.

Unless they are activated by a ground, will have to check wiring diagrams.



Question If you turn off ignition then turn off a/c and/or radio will battery drain?

If not then the other part of equation is in the igntion wiring or connectors.

If yes then you will have to look somewhere else for above

components grounding (not in the ignition wiring system) .

 

[JCook1]

Answer to Bill question.

Bill, the answer to your question " If you turn the ignition off and then turn off the other devices does the battery still discharge?"



YESSSSSS it will!



I have done the test the other respondants sugessted (check for currant draw) this evening (for me).



I work until midnight or later each night.



The current draw measured this evening was less than . 1 amp. Either the problem did not show itself to the meter or I am just unlucky.



I left the accessories on and killed the truck. I got out the meter and clamps for checking.

I pulled the Drivers battery positive lead and connected the meter positive lead to the post of the battery and the negative to the removed positive cable end. I protected the cable ends and layed them down. At this point the meter was reading 1+ amp draw. I went ahead and pulled the other positive terminal off of the passenger battery, protected it and laid it down. This left the only path for current flow through the meter. I then noticed the under hood light was on. I removed the bulb and the amperage reading was . 1 amp. I pulled the fuses in the PDC under the hood and could never get the reading to be less than . 1. I did not leave them out. I puled it looked for a change in the reading and replaced it. I did not want to mix and match and I figured that the draw would show its head if it was around.





Long post again but I am nearly bald over this one.



Jcook1

 

[illflem]

Did you put a load on it such as turning on the lights to see if your ampmeter setup was working correctly?

 

[redramnc]

Just a crazy thought - the underhood light might be your problem. I know a trunk light can drain a battery overnight. Since you were under . 1 amp without the light I would take the bulb out and see if that fixes the problem. Just a thought... ...

 

[Joe G.]

If your batteries are connected like mine the passenger side battery is connected to the cable end on the driver side battery. So if you disconnect the cable from the positive post on the driver side battery and leave the passenger side battery still connected to the cable end that measurement will NOT work. The passenger side battery will still be supplying power to the problem. This situation is NOT like in a vehicle with only one battery. You have to disconnect BOTH batteries for that current draw measurement to work. I like illflem's idea of pulling the fuses one at a time until you find the one causing the drain.

 

[JCook1]

Situation solved I hope.

I found several problems in the daylight (imagine that).



First the ignition switch conectors were corroded (why I do not know) so I replaced the ignition switch.



Then I still had a problem, although the switch was new it still would only click the starter.



Some in depth reading had lead me to believe that I had more than one problem.



That turned out to be totally worn out starter solinoid contacts.



The fact is that they would not even carry enough to click the starter.



I had to have them right now as this truck is my daily driver.

So off to the local starter rebuild place.

They charged me 40 dollars to install the contacts and test the starter.



Long story with a happy ending. I guess that I need to appoligise to the wife as the last battery problem was not her fault.



Lesson learned was read a lot and act on what you read.



Thanks all for the support you provided.



Joe G (I did disconnect the passenger battery please reread the reply above yours) I still appreciate all the responses.



Thanks All



JCook1

 

[Joe G.]

Oops, missed that on the first reading. I guess we didn't ask the right questions about this one. The starter contact problem is a recurring thing. I made a contact to replace a bad one I had before the old one failed. It's holding up pretty good but the rest of them are starting to look kind of ratty. I think I'll get some from Larryb before too much longer.



Glad you got it fixed.

 

[redramnc]

I feel a DUHHH!!!! coming on. Glad you found the problem. Brings back memories of the same kind of problem I had 20 years ago on an old 73 Chevy 3/4 ton PU - starter contacts bit me on that one but I had repressed the aggravating memory until now. I ought to remember the KISS principle - sometimes the obvious gets overlooked.



I think I will give LarryB a shout and get mine on order. At 115K miles it may not be long... ... ... ...