That is a normal relay sound. You will get a couple of amps current flow until the BCM goes into sleep mode which can take several minutes. Some of what you saw was the hood light since I bet you didn't remove it.
In case you need it:
Here is some info for determining if you have a parasiticdrain. Let me know if I need to clarify anything of if I can help in any way.
Suggest you remove the hood light bulb first so it does notprovide a drain.
For measuring battery drain I would hook up an ammeter tothe negative side of the battery by removing the negative cable and measurebetween the cable and the negative battery post.
When you connect the ammeter the car should draw severalamps until it goes into "sleep" mode which can take several minutes.Normal sleep mode drain should be 30 milliamps or less by GM standards. You willneed an ammeter that can transition from whatever the drain is down into thesleep mode. If you have a drain I suggest the following:
Once you determine you have a drain with an ammeter what Irecommend first is to listen to each fuse box and see if you hear any relaysoperating. If not, then place your hand on each relay to see if any of themfeel hot. That can be the start if you find something like that is happening.
If nothing shows up you can hear or feel then I recommendyou separate the two fuse boxes from each other. This is easy and done byremoving the Red cable from the engine fuse box that feeds the passenger fusebox. It is on the right rear side of the engine fuse box. There is a stud therewhere the large Red wire from the battery connects. Just remove the nut anddisconnect the large Red wire feeding the passenger fuse box and reattach theRed battery cable. NOTE: I would recommend disconnecting the negative ammeterhookup when working on the positive side doing this.
What you will be doing is measuring the drain with anammeter to see if disconnecting the passenger fuse box causes the drain to goaway or not. By depowering the passenger fuse box you will depower the BCMwhich controls the sleep mode so do not expect the sleep mode to happen.
If removing the feed to the passenger fuse box you then seeyou have eliminated the drain then you know it is something related to thosecircuits. If it does not reduce the drain then you know it is related to theengine fuse box. It could be a rare case where you have some drain via bothfuse boxes and we can deal with that if you think it is the case.
Just so you know, even though it may appear to be a problemin the engine or interior area the fuse boxes do feed circuits to each otherthat are not affected by separating the boxes. So, separating the fuses boxescan tell you how to narrow down your search but still not where the issue maybe. That is where the schematics come into play to track down the “real”culprit. Hope that makes sense.
Once you basically know where it is then you can removefuses and relays to see where the drain is coming from.
PS: There are cases where the alternator causes a drain soit can be disconnected and see if the drain drops.
Mr. Sam
