2002 SC430
For some reasons (hoping someone could help with) the battery will go dead in 48 hours. Sometimes it sets for weeks with no issues. Is/are there issue(s) I should look for periodic large battery draw. New Battery, dealer can't figure out issue. I have read Radio, Amp, Truck light, Auto light function. I was thinking about pulling fuses for Amp and Radio, set lights to OFF, removing truck light bulb and see if problem goes away. Good start? Any suggestions?

 

Wrong SC forum section, but basically you want to get a disconnect switch on the battery's negative terminal so you can measure parasitic draw of stuff still running after shutting off the ignition. From there, your sleuthing list is the next step to seeing if one of those changes eliminates the draw.

 

Thanks for the feedback. What SC forum should I be posting on?
It normally has half amp draw when I check. However, on occasion something is drawing more. When this happens, it brings the new battery down to 6volts in 24-48 hrs. Looking for feedback on what common cause may be. Thanks

 

It's been moved to the appropriate section... (It pays to read more closely what I said, and what part of the site you are posting on.) People more familiar with 430's are likely to chime in now.

 

The alarm on the SC430 will kill your battery if it sits for a period of time. Usually it has to be longer than 48 hours. (about 2 weeks)

You said that sometimes it dies quickly and sometimes it lasts for longer. You can test to see if it is the alarm by parking the car and not locking it.

 

its parked in a garage not locked.

 

Unless something else is going on, my experience in what you are seeing is a battery that is dying. My '07 did virtually the same thing a couple of months ago.

See if the events get closer together. That will confirm the diagnosis.

When I changed my battery, I hooked a benchtop DC power supply to the terminals so I wouldn't have to redo the settings.

I was quite surprised to see the parasitic draw to be 120 milliamps. That's significant.

Good luck. Let us know how it works out.

 

I think the battery may be going out also.

You can try this, but it is time consuming

 

How old is the battery?

 

First thing I did was replace the battery when I found it reading 6v. 5 months ago. It worked fine for 2 months and then that battery went down to 6V. After jump starting it, I took it to the dealer for proper diag. The dealer would not work on it until they replaced the battery again. So, the current dealer installed battery is 2 months old, which also went dead. Something peaks its ugly head every now and then and draws it down rather quickly < 48 hours. It mostly, works fine. Just every now and then something doesn't shut down causing excessive draw. The dealer though up their hands and gave up. I was hoping someone from this forum has seen the same issue and could point me towards the culprit. Its a sporadic issue.
The next time it happens I will clip a jumper lead to the NEG battery post and to the NEG lead. Then unhook the NEG lead from the battery allowing my jumper harness to provide voltage (as to not reset the electrical system). I will put a 1 ohm/10Watt resistor in series with my jumper leads and measure the voltage drop across the resistor. If it seems excessive, I will start removing fuses. This may work if it is caused by a radio or amp etc. However, if the CAN line is not going to sleep, it may become a tougher issue to find. This issue started after a car wash. I have read that some modules are acceptable to water intrusion but don't know which module. I was hoping someone on this forum has seen this same issue and could provide some feedback.

Thanks

 

Did the car wash result in water being in your passenger floorwell?

Did it result in water in your trunk? I would try pulling the fuse for the amp. The amp is in the trunk. I think the fuse is also

 

Check all the power seat switches, both driver and passenger sides. I had that same problem before because one of the passenger side power seat switch got stuck.