Chevrolet Silverado, Alarm kills battery

2004 Silverado ex cab w/ onstar - XM - Bose o.k. after having my truck broke into and having my digital camera stolen. I decided to get a alarm. My first alarm I had put in and my battery would go dead after sitting for a day or sometimes less. I thought it was the installer so I took it back, they claimed it wasnt the alarm. Well after I took it back to the dealer they said it was my alternator. so they replaced it 2 days later same issue. Went back to the alarm installer. they changed out the alarm for a new one. same problem after my 3rd alarm and 2 months of back and forth. they gave me my money back and took the alarm out... no problems. so I go to a diffrent alarm installer. had a diffrent alarm installed. 2 days later same issue. I really would like to have a alarm on my truck for piece of mind but have no idea why this is happening...... Anyone have a similar issue ? it seems if the truck sits longer then 10 hours the result is a dead battery. this tuck is ewuiped with a onboard computer that lets you control the way the entire car acts, like lock doors when car A. is in park B. gas is pressed B. when key goes into the ignition. Please help . .. . .. . .. . .

Well, I can say that  I have never had an alarm cause a battery to die. I have had people claim as much but never have I actually seen it happen. I would double check to make sure that the interior light is not staying on in case the installer wired into the dome light for dome light supervision improperly. I have also seen on GM vehicles a relay fail where it remains in the open position. What it does is it keeps the computer in the car on even when the vehicle is off. This would also cause this issue. I would also check with the installer and see if he tapped right into the factory wires or if the old installer left pig tails on his wires and he tapped into those. if thats the case the installer may have been careless and not tested the wires. my point there is if the old installer had doen something improperly than the new installer might have duplicated the same error.double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

I know it wasnt the dome light issue. Is it possible to run the power directly from the battery ? may that help solve any miss wire issues. As far as I know the old installer re-wired it because he thought the helper that did it at his shop did something wrong. The new installer said he had to remove all of the t clamps the old installer used, because he didnt like using them. its a crimestopper alarm if this helps.

If you take it back to the shop and ask them to check the truck for a draw on the batt they can find where it is coming from. If they dont know how to do this, then take it to another place.

If there is any draw of power off of the domelight circuit in any gm vehicle then it will cause this problem, the computer staying on. I think the second shop probably used the same wires the first shop did to wire the alarm thus causing the same issue.Certified Security Specialist

Always check info with a digital multimeter.

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wiretapper I never blamed either installer. TELL me this why does it not happen when the alarm is disconnected ??? it is not the truck I HAVE NEVER HAD A ISSUE BEFORE THE ALARM. did you read my entire post.... ? I have no issues with the truck but only issue I had was when the alarm was installed. so you are TOTALLY wrong, its been to the dealer 2 times for over a week. Ill take him a case of beer if he could fix my alarm. I hope you are not a reflection of this entire site.

ill back up wiretapper on that one because i have had install notices sent to me about how on some GMs if you use certin wires for power it will keep the computer from shutting off. it is programmable by the dealership to adjust that. also if you have ever done a remotestart in a 03+ gm you would know that they are very strange on circuit triggers. from instance if you probe the starter with a power probe just the smallest ground will even activate the starter and cause it to crank even though its supposed to be a + trigger. my suggestion would be to try pulling just the constant 12+ fuse and see if just the ground from the alarm on a circuit will still cause your batt to drain. if so than its not the power from your alarm (which ive NEVER seen happen EVER!!), its something being activated by your alarm. also who is doing your alarm? please dont say your taking it to some best buy or circuit city. those people dont know their head from their ass.

Just wondering, is it a remote start alarm? If so, what kind of bypass module does it have.

arrivalanche - I appreciate your post unlike wiretapper you gave me a good explanation of what it could be. Although I never blamed either installer. (Not a best buy ) or (cicuit city) wich he is slaiming im doing personally I think wiretapper is a AHOLE but every forum attracts them so what can you do but ignore them. x-performance - no there is no autostart on the truck. Thanks guys for trying to help me resolve my issue. I will try what you suggest arrivalanche. thanks.