Parasitic draw or bad battery
#2864873
12/26/20 12:40 PM
12/26/20 12:40 PM
|
Joined: Jan 2011
Posts: 15,859 Central Florida
larrymopar360
OP
Stud Muffin
|
OP
Stud Muffin
Joined: Jan 2011
Posts: 15,859
Central Florida
|
Been wondering if I have a parasitic draw or battery going bad in my Diplomat AHB. Battery runs down way to quick after sitting just a week to ten days in the garage. It's a big Interstate just over three years old. I finally got around to pulling negative cable and checking with multi-meter, and shows 60 milliamps. I thought this was kind of a lot, but wasn't sure, so I pulled every single fuse, and NO change.
Battery going bad? Am I missing something? I pulled every fuse. Is 60 Ma unusual necessarily?
Thanks.
Larry
Facts are stubborn things.
|
|
|
Re: Parasitic draw or bad battery
[Re: Twostick]
#2864903
12/26/20 02:01 PM
12/26/20 02:01 PM
|
Joined: Jan 2011
Posts: 15,859 Central Florida
larrymopar360
OP
Stud Muffin
|
OP
Stud Muffin
Joined: Jan 2011
Posts: 15,859
Central Florida
|
Disconnect the alternator and check it again.
Kevin Okay, will do. So are you saying 60Ma could be normal, and should always test with alternator disconnected, or that alternator might be bad (bad diode)?. I'm going to test with it disconnected, just wondering what to conclude afterward. If no change and still 60Ma then what? Or, if significant drop? Thanks, Larry.
Facts are stubborn things.
|
|
|
Re: Parasitic draw or bad battery
[Re: Twostick]
#2864910
12/26/20 02:15 PM
12/26/20 02:15 PM
|
Joined: Jan 2003
Posts: 1,893 Harriman NY
71GTX471
top fuel
|
top fuel
Joined: Jan 2003
Posts: 1,893
Harriman NY
|
Disconnect the alternator and check it again.
Kevin Feel the alt.& see if its warm,alts.can draw on a battery when there's an internal fault.
|
|
|
Re: Parasitic draw or bad battery
[Re: 71GTX471]
#2864911
12/26/20 02:16 PM
12/26/20 02:16 PM
|
Joined: Jan 2011
Posts: 15,859 Central Florida
larrymopar360
OP
Stud Muffin
|
OP
Stud Muffin
Joined: Jan 2011
Posts: 15,859
Central Florida
|
Disconnect the alternator and check it again.
Kevin Feel the alt.& see if its warm,alts.can draw on a battery when there's an internal fault. Okay will do. It was really strange that the meter never moved even a tiny bit when I pulled any of the fuses. Thanks! Larry
Facts are stubborn things.
|
|
|
Re: Parasitic draw or bad battery
[Re: UCUDANT]
#2864916
12/26/20 02:22 PM
12/26/20 02:22 PM
|
Joined: Jan 2003
Posts: 1,893 Harriman NY
71GTX471
top fuel
|
top fuel
Joined: Jan 2003
Posts: 1,893
Harriman NY
|
Ensure you have everything turned off, map lights etc. if you have a newer vehicle with an ECM etc. you will need to let it "time out" or "go to sleep" for testing the draw, this includes ensuring your door is closed (no draw from a dome light, under hood light etc.) Disconnect the negative battery terminal, now make that connection by hooking an ammeter between the batteries negative terminal and the disconnected battery cable end. This will tell you the draw. You can pull fuses and disconnect things until you find the suspect circuit. Then you will know if you have an excessive draw.
when disconnecting the neg.batt. terminal to connect a DVOM you have to hold the leeds against the terminals if it disconnects & goes open the vehi.wakes up again {on newer cars} & you have to wait for it to go to sleep again.
|
|
|
Re: Parasitic draw or bad battery
[Re: 71GTX471]
#2864939
12/26/20 02:52 PM
12/26/20 02:52 PM
|
Joined: Jan 2011
Posts: 15,859 Central Florida
larrymopar360
OP
Stud Muffin
|
OP
Stud Muffin
Joined: Jan 2011
Posts: 15,859
Central Florida
|
Ensure you have everything turned off, map lights etc. if you have a newer vehicle with an ECM etc. you will need to let it "time out" or "go to sleep" for testing the draw, this includes ensuring your door is closed (no draw from a dome light, under hood light etc.) Disconnect the negative battery terminal, now make that connection by hooking an ammeter between the batteries negative terminal and the disconnected battery cable end. This will tell you the draw. You can pull fuses and disconnect things until you find the suspect circuit. Then you will know if you have an excessive draw.
when disconnecting the neg.batt. terminal to connect a DVOM you have to hold the leeds against the terminals if it disconnects & goes open the vehi.wakes up again {on newer cars} & you have to wait for it to go to sleep again. Dodge Diplomat AHB. '89. I had help so leads were secure. Had to have help so I could pull fuses one by one.
Facts are stubborn things.
|
|
|
Re: Parasitic draw or bad battery
[Re: Andrewh]
#2864969
12/26/20 04:15 PM
12/26/20 04:15 PM
|
Joined: May 2019
Posts: 6,241 nowhere
Sniper
master
|
master
Joined: May 2019
Posts: 6,241
nowhere
|
what does the battery voltage measure just sitting there? I ran into the same question and then remembered that a battery going bad isn't going to have a high resting voltage like a new one. the battery was 12.5 volts. vs the normal 13.5 you would expect. I even ran it on a charger for a while and it came back down to the 12.5 volts after just sitting. I wouldn't expect a 13.5V reading on a battery. 12.6v is fully charged. 12.5v isn't bad at all. https://haynes.com/en-us/tips-tutorials/how-test-car-battery-multimeter
|
|
|
Re: Parasitic draw or bad battery
[Re: 5thAve]
#2864971
12/26/20 04:26 PM
12/26/20 04:26 PM
|
Joined: Jan 2011
Posts: 15,859 Central Florida
larrymopar360
OP
Stud Muffin
|
OP
Stud Muffin
Joined: Jan 2011
Posts: 15,859
Central Florida
|
I've had a lot of bad batteries the last few years. Some even loose their charge being disconnected. Others being connected even the smallest load like what the clock memory draws is enough to make a difference even if the battery holds a charge when it's disconnected.
If you have the ignition switch light make sure that goes off. That stopped timing out on a friends car. Unless there's something aftermarket the only real stuff on an M to cause drains is problems with the radio, ignition module, or a light that's not going out. Or the alternator thing that was mentioned altho I've never personally seen that problem. I thought about the ignition light but either it's burned out or disabled due to AHB. Factory radio so minimal draw there. As you mention, not much on M bodies. I'm going to test again with alternator disconnected. I did leave negative cable disconnected yesterday after testing, just to see if that changes anything. I probably won't have a chance to get back to testing it again for a week or so anyway.
Facts are stubborn things.
|
|
|
Re: Parasitic draw or bad battery
[Re: 5thAve]
#2864992
12/26/20 05:42 PM
12/26/20 05:42 PM
|
Joined: Sep 2014
Posts: 1,405 Central Pa
moparjim79
pro stock
|
pro stock
Joined: Sep 2014
Posts: 1,405
Central Pa
|
I've had a lot of bad batteries the last few years. Some even loose their charge being disconnected. Others being connected even the smallest load like what the clock memory draws is enough to make a difference even if the battery holds a charge when it's disconnected.
If you have the ignition switch light make sure that goes off. That stopped timing out on a friends car. Unless there's something aftermarket the only real stuff on an M to cause drains is problems with the radio, ignition module, or a light that's not going out. Or the alternator thing that was mentioned altho I've never personally seen that problem. Gonna add rear window defrost to list. Also, forgive me,but I've noticed in a lot of your post you feel to follow diplomat with AHB or AFB why is that?
|
|
|
Re: Parasitic draw or bad battery
[Re: moparjim79]
#2865003
12/26/20 06:01 PM
12/26/20 06:01 PM
|
Joined: May 2019
Posts: 6,241 nowhere
Sniper
master
|
master
Joined: May 2019
Posts: 6,241
nowhere
|
I've had a lot of bad batteries the last few years. Some even loose their charge being disconnected. Others being connected even the smallest load like what the clock memory draws is enough to make a difference even if the battery holds a charge when it's disconnected.
If you have the ignition switch light make sure that goes off. That stopped timing out on a friends car. Unless there's something aftermarket the only real stuff on an M to cause drains is problems with the radio, ignition module, or a light that's not going out. Or the alternator thing that was mentioned altho I've never personally seen that problem. Gonna add rear window defrost to list. Also, forgive me,but I've noticed in a lot of your post you feel to follow diplomat with AHB or AFB why is that? AHB means cop spec, lots of differences between the cop and civilian spec M bodies.
|
|
|
Re: Parasitic draw or bad battery
[Re: larrymopar360]
#2865057
12/26/20 08:58 PM
12/26/20 08:58 PM
|
Joined: Jan 2003
Posts: 15,355 Omaha Ne
TJP
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 15,355
Omaha Ne
|
Been wondering if I have a parasitic draw or battery going bad in my Diplomat AHB. Battery runs down way to quick after sitting just a week to ten days in the garage. It's a big Interstate just over three years old. I finally got around to pulling negative cable and checking with multi-meter, and shows 60 milliamps. I thought this was kind of a lot, but wasn't sure, so I pulled every single fuse, and NO change.
Battery going bad? Am I missing something? I pulled every fuse. Is 60 Ma unusual necessarily?
Thanks.
Larry Yessir and that will drain a good battery. If pulling the fues didn't identify the culprit then it is something likely connected all the time, IE: alternator as suggested, starter, starter relay (doubtful), ignition switch or wiring in the column. Has to be something that is non fused (box wise) and connected to the battery when the switch is off. I had one that drove us nuts for a bit, it was the clock motor that wound the spring. The clock didn't work so I didn't think to looks at it. However the points that open when the spring is wound were stuck shut thereby energizing the clock motor 24/7. Can't remeber the draw but it was 30ma + I think, Happy hunting and do keep up posted )
|
|
|
Re: Parasitic draw or bad battery
[Re: TJP]
#2865080
12/26/20 09:45 PM
12/26/20 09:45 PM
|
Joined: Jan 2011
Posts: 15,859 Central Florida
larrymopar360
OP
Stud Muffin
|
OP
Stud Muffin
Joined: Jan 2011
Posts: 15,859
Central Florida
|
Been wondering if I have a parasitic draw or battery going bad in my Diplomat AHB. Battery runs down way to quick after sitting just a week to ten days in the garage. It's a big Interstate just over three years old. I finally got around to pulling negative cable and checking with multi-meter, and shows 60 milliamps. I thought this was kind of a lot, but wasn't sure, so I pulled every single fuse, and NO change.
Battery going bad? Am I missing something? I pulled every fuse. Is 60 Ma unusual necessarily?
Thanks.
Larry Yessir and that will drain a good battery. If pulling the fues didn't identify the culprit then it is something likely connected all the time, IE: alternator as suggested, starter, starter relay (doubtful), ignition switch or wiring in the column. Has to be something that is non fused (box wise) and connected to the battery when the switch is off. I had one that drove us nuts for a bit, it was the clock motor that wound the spring. The clock didn't work so I didn't think to looks at it. However the points that open when the spring is wound were stuck shut thereby energizing the clock motor 24/7. Can't remeber the draw but it was 30ma + I think, Happy hunting and do keep up posted ) Thanks for reply. I'm going to first try disconnecting alternator. Hope that's it, because I actually have a spare taking up room.
Facts are stubborn things.
|
|
|
Re: Parasitic draw or bad battery
[Re: larrymopar360]
#2865191
12/27/20 11:11 AM
12/27/20 11:11 AM
|
Joined: Jan 2003
Posts: 8,025 Tulsa OK
Bad340fish
master
|
master
Joined: Jan 2003
Posts: 8,025
Tulsa OK
|
When you first take a battery off the charger you will have a "surface charge" which is really fake news for voltage. Do something like turn the headlights on for a second then back off and you will see the actual voltage after that. A fully charged 12V battery at rest should be 12.65-12.75 at rest. Even as low as 12.3 is significantly discharged and has a big effect on the output capability.
The alternator is a good place to check like mentioned before. It sure is frustrating when the item that charges the battery also discharges it.
68 Barracuda Formula S 340
|
|
|
|
|