My second set of electrical issues, my 1st set was cured by a new set of battery cables, but another more in-explainable one has appeared. Please read in full detail.

The issue occurred shortly after I cured my last electrical issue. I started the car, gave the engine a quick rev at idle at about 5k, I noticed the lights dim a bit, backed up, drove off. I noticed all kinds of crazy things on the dash, charge system fault, fluctuating battery voltage, drove the car home, and the car would not start again.

I took everything apart, rechecked cables, figured it was another battery cable issue, I used all the diagrams off this forum, double checked them, put everything back together. The car would not start, just clicking from the relay. I again took everything back apart and rechecked everything a second time, I also checked and cleaned the following under hood grounds: g106, g105, g104, g101, and g102 still no start.

Then another issue popped up, the battery would constantly be drained to the point which the car was completely dead in less than 12 hours. This happened twice, so I figured my 2 month old battery might be bad so I had that checked today and the battery load tested just fine. The history codes in the system were B503,b508,b2483,b2284,b2282,b2283,and b2285 but all codes cleared and none came back after they were cleared.

Another strange thing was that the passenger foot-well relay would no longer click it would just tick in a low hum after a couple times of trying to start the car. Also as soon as jumper cables were disconnected the battery voltage on the dash would immediately drop down to 11.9- 11.7.

The only option I have now is to take out the starter and get that tested, which I will try to do tomorrow. At this point there are no codes in the system.

I am uploading these pics and will upload any further videos/pictures to help fix this problem.
The clicking starts after I reconnect the negative battery cable.
http://s1228.photobucket.com/albums/...=VIDEO0031.mp4
http://s1228.photobucket.com/albums/...=VIDEO0032.mp4
http://s1228.photobucket.com/albums/...=VIDEO0033.mp4









With jumper cables connected



I am running out of clues, it seems like a ground issue to me but I don't really know which one, whatever is causing the problem must have come from the shaking of the engine during revving it at idle (my best guess). Thanks in advance for everyone's help. I will try to get this issue fixed tomorrow.

 

Ok, you are leaving a lot of information on the table here, which we have already discussed via PM.

You have something that is draining the battery. I provided you with Bill C's procedure on how to audit the current drain, and you never provided that info. The "clicking " sound in the video, is the headlight control module....due to a low battery condition.

 

I will toss out one place to look for a battery drain. Do you have the power seats w/power lumbar support? I know a couple of people that had a problem with a faulty switch that was causing the lumbar pump to stay running.

Both were on the passenger side.

 

If you try the easter egg component replacement method to solve this issue,,, GOD HELP YOUR BANK ACCOUNT!!!

Figure out what exactly is staying ON when the ignition is OFF!! Your proper BCM SLEEP current is very close to 20 milliamps.



BC

 

Ok a small update I went back this morning and the car had not drained the battery fully like it had all the previous days, the battery voltage reading on the dash had dropped down to 11.5 even though this is a fully recharged battery, still no start.

I will perform the battery drain test shortly, and I will take a video to better explain the sounds when turning the key to start the car.

 

I also never got a reply on this request:

"For the following check, you will need someone to assist you, while you take the voltage measurement.

With the shifter in neutral, clutch pedal pressed down, and the key to "start", check for 12 volts on minifuse #14 in the passenger footwell fusebox."

 

I disconnected the negative cable on the battery and the under-hood light, and let the car sit for a couple hours to enter sleep mode. I took measurements, and there seemed to be a negative 3.8-4.5 amp in the circuit on different readings. I will take a video if that will help you guys better understand the problem. Now I understand that 3.8-4.5 is a bit high so there might be a problem there.

 

I don't have a whole lot of help so I will attempt to do that tomorrow morning, just need to figure out which one is #14.

 

The BCM enters the SLEEP MODE, 8-12 min after
the vehicle is shut down and ALL electrical loads are secure.

The DC Amp meter needs to be placed in SERIES with the NEG Cable.
8-12 min after its connected, in series the BCM should enter the sleep/security mode if all loads are off/secure.

 

are you suggesting I only do it after 8-12 minutes? so reconnect battery let the electrics come back and then redo test?
I will post a video of me taking the reading, I feel like I have done it right.

 

Yes, that is what Bill is saying. When you reconnected the battery, everything came to life and its not in the sleep mode till another approximate 10 minutes of nothing happening. Make sure you put the meter into the battery circuit before you reconnect, then wait.

 

Ok I performed bill's test one more time today, I followed all instructions, and the battery drain had gone down a bit to 3.8-3.2 amps after about 30 minutes after disconnecting the negative battery cable, and letting the car enter sleep mode
I am uploading a few vids of me attempting to start the car from inside and outside.
In the 1st vid notice how the starter clicks in the 1st try but doesn't click anytime after that.
http://s1228.photobucket.com/albums/...=VIDEO0034.mp4
http://s1228.photobucket.com/albums/...=VIDEO0035.mp4

 

Ok i attempted to do this test today lucky but I did not have any success, I am a bit confused on the procedure. I located the # 14 fuse on the passenger footwell, but am I supposed to put both probes of the multimeter on there to test the voltage? am I supposed to take out the fuse and then put the probes on where the fuse normally goes and if so where am I supposed to put the probes? and lastly how do I dial the multimeter to I measure it in ACV or DCV?

 

I do not understand what you mean by "after disconnecting the negative battery cable". In order to do the test, the meter must be in series with the negative battery post, and the negative battery cable. What do you have the meter set to?

Please post a pic of the meter setup (connected to the battery), and pic of the meter so we can see how it's set.

 

I was trying to make it easy for you, by checking at the fusebox first. You have to pull the fuse, and probe the contact with the red lead from the meter, while the black lead is on a KNOWN good ground. If in doubt, run a wire to the negative battery post.

If you can get your hand down there, you can also put the red probe on the starter solenoid post with the purple wire connected to it, and the black lead on the negative battery post. The meter must be set to DCV.

 

I will try to get one for you tomorrow, but I believe I have it set up correctly, I do in fact have it set up in a series with the red probe set on the negative cable, and the black probe set on the negative battery post, and the multimeter set to 10A for amp current reading, and I mentioned the readings earlier.

 

What would be considered a known ground? would connecting the black probe to the chassis or the floor of my garage work as a ground?

I can also check the purple wire, I will try to that tomorrow also, thanks lucky.

 

You are certainly getting an education on electrical and needed in this case. The "Ground" is not the garage floor in this case. "Ground" on the car is the battery negative which is usually anywhere from the battey to the engine or metal frame...anywhere that the battery negative makes a connection through. You can look for one using the DVM in the OHMS mode by going across the negative cable to the engine for example and you should see "0" ohms of resistance or some very small number like "0.1" or similar.
The car has no electrical connection to the garage floor. Now if you were working on home electrical and high-power type things, a ground connection is possible on the floor but not the normal. In other words, don't have your hand on a 120volt source and be sitting on the garage floor or standing on it with bare feet...you'll get lit up in a big way!

 

As I stated, if in doubt, just put the black lead from the meter on the negative post of the battery. Grounds are referenced from the negative post on the battery. On a C5, the negative battery cable is connected to the chassis (at G104 frame), and the block (at G106 above the starter). You can always check to make sure you have a good ground point, by putting the black lead on the ground point, and the red lead on the negative battery post(with cable connected. Set the meter to resistance (ohms), and it should read in the tenths of an ohm. If you truly have the meter setup correct (like Bill's post), and you are drawing 3+ amps, you have a serious current draw somewhere, that will drain you battery in no time.

 

Ok I understand lucky I will try to perform the tests either tonight or tomorrow.


Ok so I am pretty sure that the readings are accurate, the only thing that I am doing different from bill's test is that I am giving the car a bit longer around 30-40 minutes to fall asleep, and instead of wrapping a wire around the negative battery post and battery cable, I am simply allowing them to contact the negative battery post for the black probe and the negative battery cable for the red probe. Another difference is that I my Z06 is an 04 so it has a top post rather than a side post battery, I will be sure to take pics tonight to clarify any questions.

That being said what are some things that I should look for that are draining the battery?