Door chime on with key out and intermittent battery drain.
 

First off let me say thank you to all of you that are still here keeping the questions answered. Our Blazer now has 206k on it and your efforts have helped more than once since I last posted here on the forum. Search has solved most of my problems.

I have been searching but not finding the info I need. Several times now we have noticed than the door open chime was on after pulling out the key. I have had to replace the ignition switch twice before but it seams that the switch for the passlock system must be the one that senses the key being removed and the ignition switch would not cause the door chime to activate. Is this correct?

Also we have had several times were the low battery light was on before the key was inserted in the cylinder. Wife says it cranked slow but started. Battery is about 1 year old. Checked just now and when I first hook amp meter in series with the negative lead at battery I get about .90 amp this drops several times till it was 6 ma after about 15 seconds.

Will the passlock switch sticking on cause the battery to drain?

Thanks again for still being here.

Blazeme

The door chime switch is part of the ignition lock cylinder and either the switch, or the wire for it, is shorted to ground. It will not cause a draw provided the driver door is closed, and the door jamb switch is working correctly.

GM has made changes to Passlock, almost on a yearly basis. What year is your Blazer?

Connecting an ammeter in series will check for parasitic draw. When you disconnect the battery terminal, keep alive memories discharge. When you connect the amp meter, all of the memories recharge, through the amp meter. The draw for this can be significant until the memories are recharged. Depending on the capabilities of the amp meter, it might be more than the meter can handle. To avoid this: Make sure all accessories and lights are off, all doors are closed, including the rear hatch, under hood light, etc etc, and remove the key. Then disconnect the negative battery terminal from the battery. Connect a 10ga jumper wire between the negative battery terminal and the negative cable terminal, not the attaching bolt. Allow ~10 seconds for the memories to recharge. Connect the amp meter alongside the jumper wire, and disconnect the jumper wire, leaving the amp meter connected to the battery and battery terminal. Your reading of .6 amps is too high, something is drawing. Depending on the year of the vehicle, .12 amps is ball park maximum allowable parasitic draw.

Sorry its a 2001 4x4 LT

I had .9 amp only when I first hooked up the meter. It dropped to .06 amps after about 15 sec. I guess I stated it wrong when I said 6 ma that would be .006 amp.

Blazeme

Ha, got my decimal in the wrong place too, sorry! Typical draw is ~ .012 If you're sitting at .006 and it does not increase, that's fine. Yes, eventually it will kill the battery, but with a fully charged, good, battery, it should still start the vehicle after ~10 days of inactivity.

On your 2001 Passlock, there are two components that may come into play as far as the low battery is concerned: One is the "key in ignition" switch. The wiring for the switch goes through the same harness as the ignition switch, and the actual switch itself is attached to the lock cylinder, either with a clip, or a scerw. When the key is in the ignition, it closes the switch. This is the switch that is keeping the chime going with the key removed. The second component is the Passlock sensor which is at the ignition switch. There isn't a lot of information available pertaining to how the Passlock system is programmed at the factory, (for obvious reasons). However, I suppose it's possible that the Passlock system could "time out" if the key is in the ignition for an extended period of time. At that point, parasitic draw might increase. No clue as to how long the 'time out" might be, if it even has one. There are other functions in the Passlock system that require a "wait" period of 10-30 minutes while programming additional keys, etc. If you leave the amp meter connected, you can monitor draw and see if it increases after 30 minutes or so. If you have a scan tool capable of accessing the Passlock system in the BCM, there might be a DTC indicating a problem. Using a scan tool is the only way to know if there are any codes in the BCM memory, (no lights come on if there's a problem). Might be worthwhile to replace the switch and see if it makes a difference.

Is this the switch in this assembly? List: Search for 'passlock' | O'Reilly Auto Parts

So far I don't find anyone selling a sensor other than this assembly.

Unfortunately I do not have a tech 2 or equivalent. Sure wish I did. My Innova 3160 will read DTC and ABS codes but I think that is all.

Nope, that's the housing that the lock cylinder goes in. Here is a link to the ignition switch. You can see the key switch on the left side with two wires going to it, (green & tan). It clips into the housing in the link that you posted.

BWD CS658 - Ignition Starter Switch | O'Reilly Auto Parts

The other set of 3 wires goes to the Passlock sensor.

Edit: Sorry, misunderstood, yes the link you posted has the Passlock sensor, but not the key switch.

OK so the key switch comes new with the ignition switch and the sensor is the part I reused when I replaced the ignition switch before.

I would bet the key switch is my problem. Never should have changed the ignition switch the first time, thought points were burnt but turned out to be something else. Aftermarket switch is not as good, already had to replace it after about a year as it was trying to keep the starter solenoid engaged in the run position. May have to use that lifetime warranty again.

Thanks for the help!
Blazeme

That's what lifetime warranties are for ;)

I think the sole purpose of the sensor, is to read the key. So if it starts and runs, the sensor is fine.