Battery issue

[behindbars1544]

Today I went to start my 05 Yukon and...nothing. I mean the door locks weren't even working. I called AAA for a jump and had them test the battery.
Wit a jump she started and seemed to keep good voltage but as soon as we turned the ignition off the battery voltage plummeted to almost 4volts and wouldn't start without a jump. I just purchased this truck about a week ago so I had the guy jump start me again and drove it right to the dealership. I felt like a total ass because after telling him all the BS me and the AAA tech went through and I had to keep it running because if I shut it down it would need a jump to start again, we went for a ride and when we got back to the dealership he shut it off by mistake. Just for the hell of it he tried starting it back up and ....bam...she started right up no problem. I was like, WTF!! He replaced the battery with a new one anyway but the one that was in there was only 4 months old.

Can anybody suggest WTH happened and how I can fix it?
BTW, the only thing that was left on all night was my cell phone charger which I leave on every night even with my old vehicle and never had a problem.

Thanks guys!!

 

[tt54l32v]

Battery had a short in it, ran into it the other day. That battery had about 100 more cold cranking amps than it was rated for. So I cleaned all the connections and tried a couple of times in a row and sure enough it got weaker and weaker and after 3-4 tries it wouldnt crank the engine. Let it run for about 30 minutes and it would crank a couple of times and then just short out and act like it had no connection, but with a volt meter it showed low voltage ensuring a connection was present.


In short, new dont mean shit.
Batteries made in the last 5 years are all pretty much junk and can only be trusted as far as you can throw them.

 

[OHSIXX]

Internal issue with battery like stated.....possible short or dead cell(s).

 

[behindbars1544]

God I hope so. Thanks guys!!

 

[behindbars1544]

Ok, update. Went to start the truck Saturday morning and it cranked over slow as if it didn't have much life left. Mind you this is with the brand new battery that was installed less than a week ago.

I think something is draining the battery but everything obvious turns off when I shut her down. Any suggestions on how to go about diagnosing this problem??

 

[Chiggy]

quite possibly a bad ground somewhere and it's not charging correctly. I would suggest doing the big 3 and go from there.

 

[oh1yukonslt]

quite possibly a bad ground somewhere and it's not charging correctly. I would suggest doing the big 3 and go from there.

X2. Also check your alternator. Been told a bad diode can drain a battery overnight. Also you can do a parasitic draw test using a volt meter to see if any electronics are pulling juice while off. Did you install any electronics ie: stereo etc etc?

 

[harveje]

What is the procedure for doing the parasitic test? I know on our 08 that stuff stays active for x amount of time after last door is closed. Also is there a way to trick the alternator or computer to charge more? The ECM or PCM has some kind of program that controls the charging circuit based on different variables.

 

[08grey]

I think you have a bad ground or connection. Before the new battery you mentioned the old one shorted out. And now with the new one it sounds like sits not getting a good charge which first step is to look for a bad or loose connection and it corrosion on the copper wire.

---------- Post added at 10:26 AM ---------- Previous post was at 10:25 AM ----------

You tube big three

 

[behindbars1544]

....and we're dead again this morning...
I thought these trucks supposed to have something that prevents the battery from draining to low. It's on my window sticker.

---------- Post added at 12:50 PM ---------- Previous post was at 11:59 AM ----------

Thinking it's my diablo trinity tuner draining the battery overnight. When I researched it there seems to be a lot of issues with the trinity doing this. Truck didn't give me any starting issues before installing the trinity but I only had it like 4 days before I installed it so I cant say for sure.

I called Diablo today and spoke to a tech rep and he told me to change to sleep mode from 30 seconds to 60. Mine was somehow set to 5 seconds. The way he explained it was the trinity contacts the vehicles computer every, in my case, 5 seconds for information and was "keeping it awake". Said if the trucks computer took say 40 seconds to power down and the tuner was contacting it every 5 it was keeping the computer awake and not letting it fully power down which in turn was keeping a drain in the battery.

Still don't understand why the part that supposed to prevent battery from draining to low didn't stop the drain.

 

[Rivieraracing]

Hopefully that is it, give it a try for a week or so and let us know what your come up with! Good luck!

 

[behindbars1544]

First morning with the tuner unplugged...started right up no problem. I had the dealership install a new alternator anyway. Hey, they offered, what was I supposed to say, no? Besides, I noticed the old one was cranking my voltage up to 15.20 while driving which I feel is a bit too high. I'll keep the tuner out for a few more days and report back

 

[Wake]

....and we're dead again this morning...
I thought these trucks supposed to have something that prevents the battery from draining to low. It's on my window sticker.

---------- Post added at 12:50 PM ---------- Previous post was at 11:59 AM ----------

Thinking it's my diablo trinity tuner draining the battery overnight. When I researched it there seems to be a lot of issues with the trinity doing this. Truck didn't give me any starting issues before installing the trinity but I only had it like 4 days before I installed it so I cant say for sure.

I called Diablo today and spoke to a tech rep and he told me to change to sleep mode from 30 seconds to 60. Mine was somehow set to 5 seconds. The way he explained it was the trinity contacts the vehicles computer every, in my case, 5 seconds for information and was "keeping it awake". Said if the trucks computer took say 40 seconds to power down and the tuner was contacting it every 5 it was keeping the computer awake and not letting it fully power down which in turn was keeping a drain in the battery.

Still don't understand why the part that supposed to prevent battery from draining to low didn't stop the drain.

The battery protection doesn't work for instances like that, it's more for high drain loads like the stereo system, headlights, interior lights, 12v cigarette plugs, etc. In your case the tuner was keeping the PCM awake constantly it sounds like.

I had a similar experience, not with a tuner but a monitor. I have one of the Aeroforce gauges and if I forgot to unplug it from the ODBII port it would keep the computer awake until the battery went dead. I got an unpleasant reminder a few times when I was in a hurry and left it plugged in for 8-10 hours.

I also had a separate experience very much like yours with no extras plugged into the electrical system. The battery would die very fast, sometimes after only an hour. I've only seen this one time in my 25 years of driving/repairing vehicles, but I had a short in the starter. I replaced the starter and the problem never re-appeared. It was hard to troubleshoot as the starter wouldn't get hot to the touch, the only indication was a slow crank on occasion that I was attributing to a failing battery. When it started occasionally cranking slow on a new battery, and almost failing to turn the engine over after sitting for an hour or so I took a chance and replaced the starter.

 

[behindbars1544]

Wake, My diablo trinity has the monitor screen that plugs into the ODBII port also and from the research I did supposedly that monitor was keeping the PCM awake. The guys on the Diablo forums also said to unplug it every night to avoid the battery drain but like you said, when you're in a hurry and forget...you're screwed. Plus I'm sorry but for $600.00 you shouldn't have to worry about the unit draining your battery.....

And I agree, those starter shorts can be a ***** to diagnose. It's one of those, "screw it, lets try replacing this and see if works" kind of situations.

 

[oh1yukonslt]

What is the procedure for doing the parasitic test? I know on our 08 that stuff stays active for x amount of time after last door is closed. Also is there a way to trick the alternator or computer to charge more? The ECM or PCM has some kind of program that controls the charging circuit based on different variables.

There is a guy on Youtube name Eric the car guy. Type in Parasitic draw test and look for Eric the car guy. He does a good explanation of it

 

[behindbars1544]

Well the tuner was definitely the issue because I have yet to reinstall the monitor and even after not starting it through that last big snow storm, she starts right up with no problem now. Now that I know what the problem was I can play with the settings to see if I can get it to where I can leave it plugged in and it wont keep the PCM on all night.

 

[ccapehartusarmyINF.(ret)]

ive found that having a good battery and good connections and terminals solves dozens and dozens of symtoms and issues