I had a 2005 Trailblazer that developed a similar problem. Using what I had available at the time, I used a simple digital DVM and a thick jumper wire with a large clip on one end. I set up the DVM for measuring current in the mA range. The large in rush current when you connect the battery will normally blow the mA meter fuse so this is what the jumper wire is used to prevent. Clip the large wire to the negative terminal and clip an ammeter lead to it as well. momentarily hold the other end of the large wire to the loose battery cable and then clip the other ammeter lead to the battery cable. Now let go of the jumper connection and the meter is in circuit. Normally, you can watch as the current starts out high- several hundred milliamps and drops in steps over the course of a minute or two as each computer module goes to sleep. In my case everything looked normal until I opened the door. Then they all woke up as expected but not all would go back to sleep. So I started pulling fuses until I got to the resettable (circuit breaker) fuse for the electric seats. Once I pulled that one, the current dropped back to normal. Something in the seat or seat controller was drawing all the current. It looks like this one:
Anyway, this method allows you to measure milliamps but survive the initial in rush current from all the caps charging.
Before I did any of this- I disconnected the alternator just to be sure it was not a bad diode causing the draw. Had that once- alternator worked fine but would suck down the battery overnight due to a problem diode.
New Digital MM arrived today. Charged battery fully - started at 12.77 3 hours ago now it is down to 12.50. Disconnected negative cable. Tested between post and cable = 3.00 amps. So now pulling fuses. Blades are no problem but the J-cases are going to be an issue. Does a 3 amp drain work out to the battery dying roughly every 24 hours? Sometimes it will have barely enough to start right at 24 hours but after 48 there isnāt enough to even turn on any lights.
Yes. All the blades made no difference. As I feared, the first J-case (power steering module) is totally impossible to get out without breaking. Popped the top off which I expected. Tried fingers on all sides, 3 kinds of pliers and the thing will not move. The only thing I accomplished was cracking the plastic casing so that the top wonāt go back on. Surely there must be a way to get these things out without using or buying a special tool. Iāve got boxes and boxes full of all sorts of tools and I just waited a week to get the multimeter.
Edit: thinking about what you said about waitingā¦started to lack confidence in my half-ass method of keeping those leads connected to the post and cable. Had tried clips, tape and rubber bands and thought it was possible that one or both might have moved. Giving up for the night
Decided to go back to both Autozone and Advance to have them check the battery and charging system. Both places told me the battery and alternator were fine, and no codes. But Advance told me that he couldnāt read any reserve capacity and also that there was some mystery electrical issue on the live data while the car was running (from the code reader). He said that he current jumped way up when pressing on the gas pedal and that that is not normal and that it should be steady and constant. But also couldnāt tell me what was wrong, where to look and no codes. Told me I had to go to the GMC dealer. So just fed up.
2 things - 1. Corporate may not want their store clerks saying things that might not be correct just to avoid customer being upset because they were wrong. 2 . Stop messing around and have a real shop fix your vehicle.
I expect to stay within the parameters I have to work within and I expect not to easily find an auto technician who will help for free. I also expect the Maintenance and Repair forum on Cartalk.com to have suggestions other than āyou need an auto technicianā. Do you also spend time on medical questions forums and tell people they need a doctor? How about plumbing forums so you can tell people they need a plumberā¦
Does that mean you expect to find one at all? Why would anyone work for free?
I suggest you spend quite a bit of time on YouTube and find out what you need and how to properly do a parasitic draw test and locate all the wiring diagrams youāll need. Post your results here and someone will advise you.
A 3 A draw on your battery with the car turned off, parked for a couple hours with doors locked, youāve almost surely discovered the cause of your dead battery after 24 hours. While a 3 A draw seems a bad thing, itās actually good in the sense it should be easier to find. 3 A at 12 volts means whichever fuse is supplying the 3A is probably significantly warmer than the others. Removing the fuses one by one will eventually sus out the culprit, but the tool below would make the process faster.
Note that some circuits donāt use fuses, or not the normal types of fuses. Starter motor & alternator circuits for example. Either could cause a 3A draw, but of the two, an alternator fault seems more likely. Normally Iād think of a light bulb as the cause of a 3A draw. 3A * 12 volts = 36 watts, typical for incandescent tail light bulbs, marker lights, etc. but I presume youāve verified there are no light bulbs on.
Since I canāt get the low-profile J-case fuses out without breaking them - is there a way to measure voltage drop in these fuses like in normal blade fuses? It is probably a module not going to sleep anyway so I donāt think the pulling fuses method would find the problem.
Iāve got some of those types of fuses in my Corolla. Iāve been able to pop the plastic top off to access the fuse element without much difficulty. Iāve never tried to measure the voltage drop across the fuse element though.
One idea, a fuse w/3A going through it would create a significant magnetic field. You might could use a simple magnetic compass (like Boy Scouts use when hiking) to determine which fuse is carrying the current, the magnetic field should readily deflect the compass needle.
If problem is a computer isnāt going to sleep like it should, it would be very helpful to a tech effecting a repair if you can isolate which particular module is staying on.
I apologize for asking a very dumb question: have you tried replacing your battery?
If in doubt, try disconnecting the battery while not in use. If that doesnāt fix the problem, your battery is probably bad. Obviously, you donāt want to keep doing that - it would wear out the terminals - but as a simple test, it might suffice.
BTW, if you have a lead acid battery, and it isnāt sealed (and some sealed lead acid batteries can actually be unsealed, by prying off the plastic seal), you can try adding distilled water if the fluid levels in all the cells arenāt at the top.
BTW, do not try to unseal lithium ion batteries. When exposed to air, Iāve heard the insides may burst into flame or maybe even explode, and the flames are difficult to put out - water isnāt good enough.
My 2009 has crank windows and manual door locks and manual transmission with 5 outside key holesā¦ lol
I bought it used still under factory warranty and beat them up on the price cause it was all manual, I said you will never sell thisā¦ But it was what my wife wanted/needed at the time for her jobā¦ Now it is my DDā¦ lol
I was helping my gf purchase a new car, 2015 or so.
Salesman: How can I help you?
Me: Iām helping my friend look for a new car. Do you have any with roll-up windows?
Salesman: Either says āYou are too old fashioned!!!ā or just walks away ā¦ lol ā¦
Eventually we discovered a big advantage we had, simply by mentioning āroll-up windowsā, we could get the sales-person to leave anytime we liked ā¦
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