1999 Suburban, battery keeps going flat. Is there a known power drain on these vehicles?

Question

Have replaced battery, checked to make sure underhood and interior lights are not on. I have heard of this problem with these cars before, so I wonder if there is a known cure.

I should add that the car often sits for 2-3 weeks, but my Cadillac Eldorado did too and I never had a problem with that.

Answer 1

Disconnect the negative battery cable and put a test light between the cable end and the battery post. If the test light lights, you have a parasitic drain. Pull fuses one by one until test light goes out. That will tell you the circuit to check.

Answer 2

I don't know about the '99 Suburban, but I have the same problem with my '77 Grand Prix.

New battery, new alternator. If it sits more than a day or two, it needs a jump. I have found that when I turn off the radio BEFORE turning off the engine, my alt gauge would read a little higher when I tried to restart the engine. I have resorted to disconnecting the battery cable if the car will be parked more than a couple of hours. I'm also much more aware of where I park my car, keeping in mind that I may need a jump. Needless to say, I keep a pair of jumper cables handy.

Answer 3

After it is parked the battery goes dead over night? Does it go dead while driving? Have you connected a meter to the battery when running to see what volts your alternator is putting out?

Remove your negate battery post after all of the other checks have been done and connect a test light between the negative post and the cable. If the light is bright you have a large draw on your battery. If fairly dim you do not have much. Some parasitic draw is normal. If the light is bright you need to go about finding the component that is causing it. It could be a inside light, alternator or any number of other components. Process of elimination. Best of luck to you.

Answer 4

Weird stuff. If there is a power drain, it must be very small. these trucks are equipped with a system that automatically disconnects the system from the battery, say if you leave the radio on with the ignition off. I'd take the battery in and have it tested, maybe you got a bunk one. Also, maybe the alternator is over or undercharging it. Check the alt. guage when it is running.

Answer 5

the only time i have seen this is with my bosses it sits for 3 to 4 months at a time at the storage bld in MT. we put a solar charger on it because the computer and the radio clock and memory will kill the battery over long periods of time. but if this is not what is going on than take a volt meter that and put it on the battery and see how fast the draw is. then start pulling fuses one at a time till the draw stops then you know where to look for the short. the alt. can cause this you may want to disconnect it 1st. but this is how i trace down shorts and have gotten pretty good at it. it is a slow way to go but with all the electronics on cars now it is about the only way. GOOD LUCK

Answer 6

How far do you go when you do drive it?

It takes 6-10 miles (est) of driving to recover the energy lost from starting the engine.

If you check your Owner's Manual, I believe it states that the battery should be disconnected if the vehicle is not going to be used for 25-30 days. Even though you are under this time frame, it assumes you have a fully charged battery to start with, and you may not be driving it enough to recover.

Answer 7

Find yourself a test light and have a friend put it on the battery. When it goes dim pull out one fuse at a time until the light brightens. Then read what circuit it provides for. Then bring it to a shop and have them look for a power drain. Hope it helps.

Answer 8

I had one the same year with no probs, but have all the extra outlets checked too maybe one is fried.