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Does anyone have any idea what could be messing with my car electrically? I’m just looking for advice here.

It keeps killing my batteries and this will be the 3rd battery I’ve used. 2 new and 1 used.

I’ve had the starter, alternator and battery tested and it always comes back as a bad battery even with the new battery in. I’ve definitely ensured I am getting the right battery in there too. I’ve had a parasitic draw test done as well, and there was no draw.
The car will drive great. Sometimes I’ll park for 10 minutes go back to my car and it will struggle to start. Sometimes I work with it I get it to start and then there’s no issue for an entire week. Sometimes I park, try to start my vehicle back up, and it won’t turn over after constantly trying. I will then resort to jumping the battery. This will usually get my car starting up perfectly for the next week or so, then I will end up restarting the same cycle.

So, any suggestions on what I should be looking for? I don’t know what else the issue could be and like I said the car keeps killing these batteries. Any advice on what to do would be great. Thank you.
 

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Prev: 2018 ATS 2.0T NOW: 2020 CT4-V JR
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I haven't had this type problem in years, so I am just guessing on recent cars.
It sounds like you have checked what needs to be checked.

Again I am guessing. Maybe it could be an intermittent bad alternator that doesn't charge the
battery. Then when the Alt stops, the battery gets discharged. Maybe a bad/loose ground.

You could try looking at the battery charge number in the DIC and maybe see when it's not
charging.
 

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2013 ATS 3.6L Luxury
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Agree on intermittent alternator problem, and on monitoring battery voltage in DIC while driving. Could also be a loose connection in charging system.

Read post 4 in this thread for info on charging scheme used on these cars:


Check my voltage observations before and after battery RnR in this thread:


Intermittents suck, some of the worst problems to troubleshoot. If no loose connections etc found, I'd try a new alternator. And have new alternator tested before install. I've troubleshot problems to a component, RnRd, only to have same symptoms. Troubleshoot again, come back to same component. New part bad. In fact I can remember a guy on here with charging problems, RnRd alternator, same thing. 2nd replacement alternator fixed it.
 

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2014 ATS 3.6 Premium RWD, 2016 Corvette Z06, 2018 GMC Sierra Denali 2500HD Diesel
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The won't start after a 10 minute stop is the one that surprises me the most because otherwise I would think this is an intermittent parasitic draw. As an example, when my 2008 CTS was new I had to jump it a couple of times after it sat for a day or two and I traced the issue to a relay that was intermittently sticking and leaving the OnStar module powered up after the rest of the electrical system shut down. Having to trace this out myself was my first solid clue that the dealership I had been using for two decades had gone to hell but at least they did replace the board and battery after I diagnosed the problem for them. Any chance the battery was already very low before that short stop when it wouldn't restart? Anything that takes a fairly well charged battery down to no start, especially for a fairly small displacement engine, in 10 minutes should be creating a lot of heat and some obvious sign of problems.

If the system isn't charging when the engine is running, you should get a charge system alert in the instrument panel and you would likely also get a message letting you know that the electrical system has gone into conservation mode and is shedding all non-critical loads. This message should be triggered whenever the ECM commands the alternator to increase charge rate and it doesn't respond. An alternator with a failed diode can cause discharge when the engine is shut off but normally this sort of failure isn't intermittent.

Do you trust that the shop doing the battery test is doing a proper load test to ensure it is the battery truly being discharged and not a problem with the cabling in the vehicle?

Although it is something of a pain, the simplest method to determining whether it is an intermittent high parasitic draw that is doing this is to place a small fuse in series with the negative lead and let the car sit for some time to see if the fuse blows. A 2 amp fuse should carry any normal housekeeping chores that occur while the car is shut down but will blow on an abnormal load; of course don't try to start the car or use any of its functions while this fuse is in place or it will blow because of that draw. A DC current probe around the cable with a data logger is a better way of doing this but that isn't the sort of gear that most owners (are test shops) are likely to own.

Rodger
 
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17' 6MT ATS Carbon Black, 09' Malibu, 08' Infinity G35x, 04' Ion Redline,
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Do you have anything aftermarket on the car (alarm, remote start, stereo)? Can you confirm everything turns off after you exit the car?
 
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