Allpar Forums banner
1 - 20 of 32 Posts

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #1 ·
Hello! I started to try and isolate the parasitic battery drain on my 07 Touring. I first made sure the amp I installed wasn't the problem; I wired a kill switch to the amp from the battery, and still the battery dies overnight. So, I got the ammeter set up and started pulling fuses one by one, and when I got to Fuse #14, the draw fell off. Yay!

However, the deep dive this has now led me to is no bueno, Carlos... Fuse 14, as I can tell from the service manual (Section 8W), links to IOD/CCN INTERIOR LIGHTS. I do not have any idea what that means other than it could quite possibly be ANYTHING connected to CAN bus?? Per the wiring diagram, I'm looking at circuits A412 and A418. I can't find any detail on these, other than they are fed to Pins 15 and 16 of Connector 7, and I can tell you the color of the wires and their gauge.

What I'm thinking at this point is I'm going to wire up a switch into the 10A circuit so that I can kill and activate it from the interior. But if there is anything anyone can provide me with in the way of a cure here, I'd appreciate it.
 

·
Super Moderator
Joined
·
32,832 Posts
How much current was it drawing before you pulled the fuse? Did you have the key removed and doors closed for several minutes before taking the reading, so that the module would time out? Did the problem start immediately after the installation of the amp? What fuse or circuit powers this amp, and is it live with the key off (it should not be)?
 

·
Registered
Joined
·
5,060 Posts
. . . . I started to try and isolate the parasitic battery drain on my 07 Touring. I first made sure the amp I installed wasn't the problem; I wired a kill switch to the amp from the battery, and still the battery dies overnight. So, I got the ammeter set up and started pulling fuses one by one, and when I got to Fuse #14, the draw fell off. Yay! . . . .
You are going to need a meter that can measure in a range of 10 amps down to milliamps. Initially modules will have a rather higher amperage draw (possibly 1 - 2 amps) which will decrease over time to a range of 10 - 30 milliamps. What is the milliamp current draw change when you remove fuse #14.

. . . . However, the deep dive this has now led me to is no bueno, Carlos... Fuse 14, as I can tell from the service manual (Section 8W), links to IOD/CCN INTERIOR LIGHTS. I do not have any idea what that means other than it could quite possibly be ANYTHING connected to CAN bus?? Per the wiring diagram, I'm looking at circuits A412 and A418. I can't find any detail on these, other than they are fed to Pins 15 and 16 of Connector 7, and I can tell you the color of the wires and their gauge. . . . .
IOD means ignition off draw and is a small, parasitic electrical drain on the battery. This current draw should be in the range of 10 - 30 milliamps. CCN is an acronym for Cabin Compartment Node. Another name for CCN is the instrument cluster module. The instrument cluster is connected to one of the two CAN bus networks in the vehicle.

The instrument cluster controls interior lights and keeps the interior illuminated for 2 - 4 minutes after ignition key OFF and all doors closed. If an interior light is left ON the instrument cluster should turn it off after the 2 - 4 minute wait.
 

·
Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
22,709 Posts
You can have a visual indicator of a current drain by placing a 12v bulb in series with a battery connection. I use the peanut (sidemarker-type) lamp and alligator-clip jumper wires as it doesn't take much current to light it. You can then disconnect the items on that IOD circuit branch one-at-a-time to narrow the list of suspects down to the culprit (when the bulb goes out or very dim).

Rectangle Table Parallel Font Diagram




The electronic modules always draw some current to keep memories stored and clocks running, this is normal and in the order of a couple of dozen mA (milliamps) while the modules sleep. A good battery should last about 2-3 weeks with this low residual draw.

If a module is kept awake, it will draw more and can keep things on. This can happen with Bluetooth devices and transponders like EZ Speedpass, etc kept inside the car.

I had once had a customer's minivan with a dying battery problem and it turned out to be a child's toy in the backseat that had Bluetooth headphones that was keeping the modules awake overnight.

Get the battery tested at an auto parts store first, so we aren't chasing our tail. If the measured CCA (cold cranking amps) is what the battery is rated for, it should be good. If the store offers a comprehensive electrical test for free, get it done.
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #5 ·
Y'all, thanks for the responses. So here's what I did. I couldn't remember the values from the last test, so I did a new one.

I have a CEN-TECH Multimeter, model 61593, which measures 20A to 2mA, and the symbol is an A with a solid line above three dots. Next to that, there is aj ammeter that measures 20A and 200mA, with a symbol like this: "A~" . I'm not sure what the difference is, but I used the first set. First, I left all the doors closed and didn't put the key in the ignition, I pulled the negative terminal off the battery, waited about 30 minutes, and then clamped the positive lead to the negative battery post, and the negative lead to the negative battery terminal. I put the Multimeter dial at 20, and turned it on. The display read 0.24A, and then dropped to .04A.

After a few minutes, I opened the driver front door (with the setup exactly the same), and the reading spiked to 3.51A. After 30 seconds or so, it fell to .47A, and hung there almost 2 minutes before falling to 0.0A. I didn't think that seemed right, knowing clock radio et al take at least a few mA to maintain function. But I repeated the test and opened the driver front door again. This time, the display spiked to 3.51 like before, but stayed there for about a minute. Then, it finally fell to .80A. It had been there a full 15 minutes when I started typing this post.

I pulled Fuse #14 (10A, Red), and the reading fell to .31A. After 2 minutes, I replaced Fuse #14. The reading spiked back to .80A, and remained there (with minor fluctuations +/- .05A) until I finally pulled the battery 5 minutes later.

Observations during the test: All interior lights go out. Instrument cluster is dark. Radio and Amp have no power. Cigarette lighter has no power. There are no other bluetooth or IR/wireless devices or systems in the vehicle.
 

·
Super Moderator
Joined
·
32,832 Posts
These readings are all normal. And yes, the first range, that you used, the flat line, indicates DC. The wave symbol indicates AC current, which you aren't measuring here.
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #7 ·
Thanks, Bob. If these are normal, though, why does the result vary between the first test and the second? Also, I performed the test with all four doors, met with similar results all 8 times. The first time I open a door, the meter reads 3.51A, and after a short period of time, it steps down at 30 seconds to .47A, and then after a minute to between .04 and .01A. But the second time I open that same door, the reading only goes from 3.51A to only .80A after 30 seconds, and stays there?
 

·
Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
22,709 Posts
To aid in your 'process of elimination' of possible current draw culprits, try disconnecting the PCM to see if that 0.80A draw goes away.
The PCM does run certain tests with the key off. None should deplete a battery in normal operation.

An NVLD test description from the Motor website:

"Once the engine is turned off, the powertrain control module (PCM) waits a predetermined amount of time and then the PCM checks the fuel tank pressure sensor. If the pressure is greater than approximately 1.5 in.-H2O, the test is aborted. If the pressure is within range, the FTP sensor value is recorded and the CVS is commanded closed, sealing the evaporative emissions system. All of this is happening while the vehicle is completely shut off".
 

·
Registered
Joined
·
5,060 Posts
. . . If these are normal, though, why does the result vary between the first test and the second? Also, I performed the test with all four doors, met with similar results all 8 times. The first time I open a door, the meter reads 3.51A, and after a short period of time, it steps down at 30 seconds to .47A, and then after a minute to between .04 and .01A. But the second time I open that same door, the reading only goes from 3.51A to only .80A after 30 seconds, and stays there? . . . .
The CCN module (instrument cluster) is a node on a CAN bus network. It is possible that something is keeping the network active (not allowing sleep mode) and this is resulting in a 800 milliamp (0.80 amp) draw. You would need a scope attached to the CAN bus + and CAN bus - to determine if the network is active and not going to sleep.

Also there still could be another module in the vehicle that is not going to sleep. In the service manual page 8W - 13 - 1 table of contents lists the numerous electronic modules iin the vehicle.
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #10 ·
Yes, there are SO MANY! lol
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #11 ·
Do you recommend a OBD-II/CAN protocol scan tool? I can get one for about 80 bucks from Harbor Freight, or Autozone...
 

·
Registered
Joined
·
5,060 Posts
. . . .Yes, there are SO MANY! lol . . . .
You stopped your investigative diagnosis with fuse #14. You should continue and pull fuses #15 through #36 and note the electrical current drop associated with a particular fuse if any. When you find a fuse with a large electrical drop when removed then look at the wiring diagram for that device / module.That will narrow down the source of the parasitic draw. Page 8W - 13 - 1 lists all the fuses and the related wiring diagram for that fuse.

. . . . Do you recommend a OBD-II/CAN protocol scan tool? I can get one for about 80 bucks from Harbor Freight, or Autozone... . . . .
A cheapy $80 scan tool will most likely read powertrain codes (Pnnnn codes). It will not interrogate the other modules in the vehicle for possible codes (TIPM is an example). To obtain a more sophisticated scan tool that will review all electronic modules in the vehicle then you will have to spend hundreds of dollars. Do you want to make that kind of investment?

I am thinking a sophisticated scan tool probably is NOT going to be of much use in tracing a parasitic electrical current draw. A meter that measures milliamps and tedious and methodical checking of all fuses is your best approach to solving the issue.
 

·
Super Moderator
Joined
·
38,903 Posts
I had an odd parasitic draw in my 2007 Dodge Magnum. Only happened when the car was in the garage. Found out as long as I locked the car it never happened. Then I replaced the PCM for an occasional no crank issue and the battery drain never returned. I don’t know what in the old PCM was keeping something awake.
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #14 ·
You stopped your investigative diagnosis with fuse #14. You should continue and pull fuses #15 through #36 and note the electrical current drop associated with a particular fuse if any. When you find a fuse with a large electrical drop when removed then look at the wiring diagram for that device / module.That will narrow down the source of the parasitic draw. Page 8W - 13 - 1 lists all the fuses and the related wiring diagram for that fuse.
I, in fact, did pull all the fuses--sorry, I should've clarified that. It was just Fuse #14 that caused the draw to drop significantly.

A cheapy $80 scan tool will most likely read powertrain codes (Pnnnn codes). It will not interrogate the other modules in the vehicle for possible codes (TIPM is an example). To obtain a more sophisticated scan tool that will review all electronic modules in the vehicle then you will have to spend hundreds of dollars. Do you want to make that kind of investment?

I am thinking a sophisticated scan tool probably is NOT going to be of much use in tracing a parasitic electrical current draw. A meter that measures milliamps and tedious and methodical checking of all fuses is your best approach to solving the issue.
Yeah, no...I'll pass on that. I looked at AllData, and while the tool is relatively cheap, the subscription is 3 grand a year. I'd only foreseeably use it this one time, so that makes no sense. The $80 unit says it does both OBD-II DTC and CAN, but if it is limited, I'm going to do as you suggest--painstakingly trace it out system by system. Less expensive, more thorough.
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #15 ·
I had an odd parasitic draw in my 2007 Dodge Magnum. Only happened when the car was in the garage. Found out as long as I locked the car it never happened. Then I replaced the PCM for an occasional no crank issue and the battery drain never returned. I don’t know what in the old PCM was keeping something awake.
I should also have stated that I did replace the PCM. I found a great deal on a pre-flashed direct replacement, and the installation was 100% plug-and-play. This cleared up the low-idle issue I was having, but otherwise did nothing. The main reason I replaced it was because aside from the parasitic draw, occasionally the car will randomly go into "security shutdown" when I try to start it--where the car starts, but then shuts off and a red dot appears on the IC. If I pulled the battery briefly, it would start up with no problem, but would eventually do it again and I'd repeat the process.

I went to the dealer to replace the key, thinking that the key fob was failing, but the technician said he got an error that the programmer couldn't communicate with the PCM to program the new key. He suggested that the PCM may be corrupt. When I replaced it, I was hoping that would fix the problem. Spoiler alert: it didn't...
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #16 ·
Ok, an update, here. I decided to try and "trick out" the cabin in order to address the problem. I was going to wire a switch into Fuse #14, buying one of those sick racing mod switches, running it into the dash and then I could disable the circuit and enable on demand. This would've been great; I wouldn't have to spend hella time and money on fixing the drain. First, though, I needed to make sure the problem would go away with Fuse 14 pulled.

On Saturday, I got new headlight assemblies (the OEM were so gunked up i could barely see at night), and so when I got home Saturday night from work, I simply pulled Fuse 14 from its cavity and let the car sit overnight. I then set to replacing the headlights (what a PITA--thanks, Chrysler! But that's a whole nutha post...), and when I finished, I went to take my daughter out to practice her driving. THE BATTERY WAS DEAD.

So, Fuse 14 was NOT the bane of my existence after all. I'm utterly confused now. I guess I'm going to have to drag it over to a shop to find out what's wrong; and, judging by how long it took them to find out why the Radiator Fan wasn't working, this could be a while. And expensive.

...Anyone in the Atlanta GA area want a 2007 Cruiser...? Going cheap... lol😆
 

·
Administrator
1974 Plymouth Valiant - 2013 Dodge Dart - 2013 Chrysler 300C
Joined
·
37,779 Posts
Could the dead battery have been from something unrelated? I found a "battery drain" in my PT, years ago, was from one of my kids turning on their reading light. If something like that happened when Fuse 14 was pulled, it would confuse matters. (Nuisance variable, if I remember the technical term correctly.)
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #18 ·
Could the dead battery have been from something unrelated? I found a "battery drain" in my PT, years ago, was from one of my kids turning on their reading light. If something like that happened when Fuse 14 was pulled, it would confuse matters. (Nuisance variable, if I remember the technical term correctly.)
I don't honestly know anything that would cause it. Other than the JVC stereo and the BOSS amp, and the repair of the Radiator Fan Relay Circuit, nothing is different from the OEM wiring. I am going to try removing the stereo next and see if I wired something up wrong, but I can't imagine I did. I had to buy one of those harnesses that has the CAN bus capability for RAP, but I wired it to the way the instructions said. It's very frustrating. I've only had it a few months, and I don't recall it having this problem before I replaced the stereo.
 

·
Super Moderator
Joined
·
32,832 Posts
I once wired an amplifier into a car stereo. I put them both on the same power wire off the ignition, but the distortion was horrible. So I wired the amplifier to a fused wire to the battery.
Shortly after that my battery went dead, and the amplifier had been running VERY hot. A short in the unit killed the battery.
 

·
Registered
2007 Chrysler PT Cruiser Touring in Cool Vanilla
Joined
·
45 Posts
Discussion Starter · #20 ·
I once wired an amplifier into a car stereo. I put them both on the same power wire off the ignition, but the distortion was horrible. So I wired the amplifier to a fused wire to the battery.
Shortly after that my battery went dead, and the amplifier had been running VERY hot. A short in the unit killed the battery.
I had to get a specific wiring harness that would allow me to keep "retained accessory power". I wired the HU into that, like the original radio was, and ran a fused wire off the battery for the Amp, as I was instructed. The amp is grounded to a sanded spot of the floor under the passenger's seat. At first, I thought the Amp was wired wrong, or was drawing too much, so I wired a kill switch into the power wire. When that didn't help, I started working on the signal trace. So the radio and wiring harness has been pulled now, and the amp kill switch is off. Now we wait...
 
1 - 20 of 32 Posts
Top