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Covid-19 bought me some time to sort the intermittent battery drain issue.
After trying to pull fuses and read the meter I bought a meter with memory function cause measurements where all over the place and the standard meter shuts down after a couple of minutes.
Meter is in line with the negative battery lead and measurements are done while the car is locked using the remote, so alarm is enabled.
With all fuses in place I get the following measurement which shows a intermittent 2.2 Ah peak after the 3 minute shut down procedure.
While fulling fuses in the earlier stage I noticed fuse 40 (gateway control unit) is responsible for a large part of the current draw. Pulling fuse 40 leads to a less intermittent peak of max 1.2 Ah.
The problem I have is that it is hard to reproduce the measurements, for example: Pulling fuse 40 + fuses 1 till 13 give the reading until 1700s, after that I put fuse 40 back, as you can see this gives an entirely different measurement and higher peaks then before.
This is the same problem I've had with the normal meter, pulling a fuse could cause a 500 mA drop but putting back the fuse doesn't increase the current with 500 mA.
It sometimes looks like pulling one fuse is affection another one.
Any ideas on how to tackle this problem? Any ideas on why the gateway would draw that much current?
Are the tests perfectly replicable or is there some randomness if you repeat the same procedure?
Please provide year/options and any other background info for further help.
Are the tests perfectly replicable or is there some randomness if you repeat the same procedure?
Please provide year/options and any other background info for further help.
Of course....it's a '04 CTT
One of the problems is I can't reproduce the measurement, the 2.2 Ah peak is intermittent.
Wanted to do the voltdrop method today so hooked the battery to the charger over night to start fresh.
As I learned the shutdown procedure could take up to two hours I hooked up the meter, latched the doors and the hood and disabled the interior alarm.
After 2,5 hours there was only one peak.
Started the car to reset and power all systems and running a new long test right now.
Are the tests perfectly replicable or is there some randomness if you repeat the same procedure?
Please provide year/options and any other background info for further help.
Regarding the background: As far as I remember the issue started somewhere around februari '19 after installing a dashcam. Unplugging the dashcam didn't solve the problem. Other thing I changed before that was the blower motor, as I couldn't think of a reason why the blower motor would drain the battery, as it isn't live after shutdown, I first changed the battery which was old. This also didn't solve the problem
In the summer the problem didn't occur very often but after the summer when it was getting colder I had a flat battery every now and then, so hooked it up to the charger every other day.
I recently replaced the blower motor again as it was starting to make some noise and put in a better quality motor. I was suprised to see that it looked like the draining issue was gone. A month went by before I took the car to an indy for some small repairs. I was curious about what would happen if the car was sitting for a couple of days, again the battery was flat. The mechanic says they don't lock the cars in the garage, this could be the reason for the drained battery as the car draws quit some current on "standby".
So perhaps the blower motor was the reason after all but the quarantine looked like a good time to take a look at it.
Another 2 hour reading after starting the car to make sure all systems have been powered.
Again only one peak and a steady 50mA for the rest of the time.
Twisted the probes so we have to read up side down
Gone do one more with doors and hood closed and interior alarm activated, for now thats the only difference compared to the earlier measurements.
The first thing I would do is check/replace the blower resistor. When they go bad, they can draw current even when the car is off. There is at least one 04 CTT that had to have a wiring harne$$ replaced because the blower fan resistor burned up the wiring when the car was sitting. It is up behind the dashboard and sounds suspect since you have also been having blower fan problems.
It's driving me nuts.
Did a couple of long measurement with doors and hood closed, interior alarm activated, nothing strange happens.
In the meantime I installed the Ctek Battery Sense so I can check the status of the battery without doing anything, again some random drain.
For example:
Plugged the battery on to the charger on may 2nd and unplugged it in the evening, according to the battery Sense it was a 100% at that time.
Left for a 2 hour drive on may 3rd around 11:00 am, battery still 100%. After returning I checked the status at 16:28 pm, 21:40 pm and 22:49 pm, every time still 100%.
This morning I checked around 06:41, still 100%, and then the magic happens. 08:30 97%, 09:34 95%, 11:12 89%.
Tried the voltage drop method a couple of times but as it is random it's hard to find.
Thought I noticed some drain from the audio system but it's hard to pinpoint, noticed some voltdrop over the PCM, the CD-changer and the amplifier but very random.
Dry carpet is not a good indicator of water infiltration into the interior from plugged drains. I cleaned out the front drains even though the carpet did not feel wet and there was no "sloshing" during acceleration, braking, or cornering to alert you to water leaking into the car.
The weird part of my drain on the battery was that a clamp-on ammeter produced a very low, less than 0.1 amp, drain. The battery would die in about 5 days before cleaning the drains. Allowing for time to dry the interior with our dry late-summer climate, once the interior dried sufficiently, the battery stopped dying, but the clamp-on ammeter still shows about 0.1 amp draw.
Also, you can't just take a reading of the draw after turning off the car... power drain is higher if you don't lock the car! Over 10 minutes or so, various systems shut down, and the power drain drops from 11 amps or so all the way down to 0.1 Amps over the 10 minutes after you turn the engine off. If you lock the car after turning off the engine, the power draw on the battery goes down to 0.1 amp or so very quickly, not even 30 seconds as I recall. So depending on the state the car is in, your amp readings may or may not reflect what is really happening.
When the most common non-water-leak sources are checked and thought to be fine, water infiltration is the problem every time. Some have reported water sloshing inside a door, another person reported water sloshing somewhere on the passenger side between the firewall and inner fender, but mostly, the problems seem to be the wiring harness being wet in a low-spot of the floor that keeps any draining water trapped. The padding under the carpet can be wet when the carpet is not wet. Trouble spots are splices that occur at random locations as one spool of wire runs out during harness fabrication, the new spool of wire is connected to the old used-up spool but that leaves a water infiltration route. Connectors in the harness can also be a problem if a connector happens to be sitting in a wet low spot of the floor. The water essentially becomes a liquid conductor, so any wire carrying any amount of voltage can have that voltage partially drained off when water can get to any exposed section of conductor... including splices, and non-sealed electrical connectors.
04-17-2020, 06:56 AM
Battery drain
