Parasitic Draw Test

[Larry07Yukon]

I've been having issues with my 07 Yukon Denali not starting over the past year. The battery is supposed to be a year old and tested fine when Advance Auto tested. Alternator also tested good.

I do have a 4.5A draw (huge) from the test at Advance Auto and when I tested with my own voltmeter.

Problem though is as I try to locate the drain, the car alarm goes off (horn beeping).
(neg battery cable disconnected, red voltmeter on the negative cable, black voltmeter on the neg post, after 10-15 seconds it activates the horn)

With the hood open, I closed all the doors, locked the car, and depressed the hood switch on the latch. Came back several hours later and the horn still keeps going off after 10-15 seconds

What is going on? I need to check each fuse but the horn and possible lights are going off.

 

[08grey]

Factory alarm?

Sent from my SM-G950U using Tapatalk

 

[Larry07Yukon]

Factory alarm?

Sent from my SM-G950U using Tapatalk

Yes, the car is pretty much stock

 

[02Lightning]

I was testing mine a while back because I thought I had an issue. It was drawing 4.5 amps at first when I first hooked the meter up, and then the computers started shutting down, and then it was pulling .0 something after that. I did have some instances when hooking the meter up, the alarm started going off. Can you just hit the unlock button on your key fob and keep testing?

 

[02Lightning]

After re-reading your post. Is the meter pulling 4.5 amps up to the point the alarm goes off? I’ve hooked the battery up before and the alarm instantly goes off. Kind of sounds like a loose connecting somewhere. Can you make the alarm go off with the battery hooked up, by shaking wires or the fuse box? My problem ended up being a bad battery.

 

[Larry07Yukon]

After re-reading your post. Is the meter pulling 4.5 amps up to the point the alarm goes off? I’ve hooked the battery up before and the alarm instantly goes off. Kind of sounds like a loose connecting somewhere. Can you make the alarm go off with the battery hooked up, by shaking wires or the fuse box? My problem ended up being a bad battery.

I'm not sure what the meter is pulling after the alarm goes off, I pulled it off in fear of damaging something. The alarm also turned off.

When I reapplied the negative cable, the alarm started again and I turned it off with the key.

Once the neg cable is clamped on the neg terminal, I didn't have any issued with the alarm going off.

 

[Larry07Yukon]

I was testing mine a while back because I thought I had an issue. It was drawing 4.5 amps at first when I first hooked the meter up, and then the computers started shutting down, and then it was pulling .0 something after that. I did have some instances when hooking the meter up, the alarm started going off. Can you just hit the unlock button on your key fob and keep testing?

I thought the same thing, hopefully the computer shut down and I would be pulling less than 50MA. But I let the car sit overnight, roughly 9 hours and it was pulling 4.5A still

 

[02Lightning]

So it was still pulling 4.5A with the meter still hooked up all night? If so, can you start pulling fuses at that point and tell when the amps drop?

 

[Larry07Yukon]

So it was still pulling 4.5A with the meter still hooked up all night? If so, can you start pulling fuses at that point and tell when the amps drop?

I didn't have the meter hooked up all night, my neighbors might have killed me with the horn presumably going off all night too
Just the neg cable disconnected overnight

 

[02Lightning]

Ok, well that makes sense. As soon as you hook up the meter in between the battery and disconnected cable, it’s going to pull 4.5A no matter how long you let it sit, because all the computers are starting up for the first time. Then all the computers start to go to sleep and the amps should drop to .0 something. Seems like my amps would drop after about 3 min. Can you pull the relays for the lights and horn and then test?

 

[Larry07Yukon]

Ok, well that makes sense. As soon as you hook up the meter in between the battery and disconnected cable, it’s going to pull 4.5A no matter how long you let it sit, because all the computers are starting up for the first time. Then all the computers start to go to sleep and the amps should drop to .0 something. Seems like my amps would drop after about 3 min. Can you pull the relays for the lights and horn and then test?

I can give that a try, thanks for the suggestions.

 

[Larry07Yukon]

So it was still pulling 4.5A with the meter still hooked up all night? If so, can you start pulling fuses at that point and tell when the amps drop?

Well that was a hoot. Instead of holding the leads with my hands, I decided to clamp down the negative terminal and place into the negative cable. I must have made a much nicer connection because it didn't start the alarm.

4.5A pops up as usual and within 30 seconds the amps dropped significantly. After a few minutes, it bounced around 0.050 and 0.062

So I guess I don't have a parasitic draw.
I don't know why the battery dies so quickly, as in I can't be at the gas station filling up with the car off, radio on and charging a cell phone without the car dying. Despite what the dealership told me and Advance Auto, I probably need a new battery. I'm thinking AGM Diehard

 

[zbad55]

It sounds like your not sure how old the battery is for sure. I don't trust advanced auto that much either with the meter they use. I would just pick up a new battery and you should be fine, .05 Ma is fine for a draw on these new cars/trucks. You also dont really need an AGM battery, stock replacement would be fine,

 

[Larry07Yukon]

It sounds like your not sure how old the battery is for sure. I don't trust advanced auto that much either with the meter they use. I would just pick up a new battery and you should be fine, .05 Ma is fine for a draw on these new cars/trucks. You also dont really need an AGM battery, stock replacement would be fine,

I bought the Yukon last year, according to service records, the battery was replaced less than a year prior.

Each time I test drove the Yukon, it needed to be jumped.

The battery at most is between 1.5 and 2 years old.
However, I told the GMC dealer I'll only buy the truck if they put in a new battery. Since they were the servicing dealer and the battery was still under warranty, they said no problem.

Knowing how scummy dealers are, I suspect they ran a diagnostic, battery came back fine, and they wouldn't be able to warranty the battery. Instead of really putting in a new battery, they probably threw it on a charger and figured lying to me was easier.

Perhaps an AGM is not needed, but I've run them for close to 20 years (damn ) and an extra $65-$75 isn't going to kill me

 

[SnowDrifter]

Battery testers vary a lot. Some use a small DC pulse to check resistance and extrapolate from there. Others put a large load on the battery and measure directly. The former can give a lot of false info.


Measured at the battery, what's your charge voltage? Battery voltage after just shutting off the car? And battery voltage after sitting for an hour? What's battery voltage when you attempt to crank it?

When you jump it, where are you attaching the leads?

 

[Larry07Yukon]

Battery testers vary a lot. Some use a small DC pulse to check resistance and extrapolate from there. Others put a large load on the battery and measure directly. The former can give a lot of false info.


Measured at the battery, what's your charge voltage? Battery voltage after just shutting off the car? And battery voltage after sitting for an hour? What's battery voltage when you attempt to crank it?

When you jump it, where are you attaching the leads?

When jumping I use a jump pack (great purchase, saved me lots of headaches). I connect the positive direct to the positive terminal and the negative to the bolt coming off the block

I haven't measured battery, but here is what Advance Auto printed out for me

 

[thompsoj22]

just my opinion, i would absolutely replace the battery cables, inspect the **** fuse mounted on the firewall near the battery area and run a new ground wire/cable directly from the alternator case/mount to the negative post on the battery. it seems like alot but the fact that your battery has absolutely no reserve amps imo indicates an in sufficient charge to the battery. i would not throw a high end battery in that environment without finding out whats wrong with the charging system. also if your truck has RVC replace the current/temp module that is attached to the negative bat cable near the battery, Ebay $20.

 

[Larry07Yukon]

just my opinion, i would absolutely replace the battery cables, inspect the **** fuse mounted on the firewall near the battery area and run a new ground wire/cable directly from the alternator case/mount to the negative post on the battery. it seems like alot but the fact that your battery has absolutely no reserve amps imo indicates an in sufficient charge to the battery. i would not throw a high end battery in that environment without finding out whats wrong with the charging system. also if your truck has RVC replace the current/temp module that is attached to the negative bat cable near the battery, Ebay $20.

What is RVC?

What should I be looking for on the **** fuse?

Do you happen to know the part #s I should be looking for?
Are there three cables to replace?
Part #:25814777 Positive; Except Auxiliary Camper Battery (TP2); Provisions 12 Volt Power (9L4)
Part #:25875320 Starter Cable
Part #22846471 Negative; Except Provisions 12 Volt Power (9L4)

 

[Larry07Yukon]

I probably should note that the previous owner replaced the alternator. I forgot the date based on the Carfax report, but it was fairly recent

 

[02Lightning]

The amps dropping falls in line with what my Denali does. I did experience the alarm going off as well a couple times trying to keep the clips on the battery. I suspected you weren't getting a good connection all the time and caused the alarm to go off, but hard to tell over the internet. I've also had the same problems with the battery when my car was new. Dealer tested the battery while under warranty and it was good, auto parts tested it ok and I always had problems with it dyeing really easy. I replaced the battery and that solved all my problems. Good luck.