Hi there. I have post that I will give for answers.
gm tech bulletin 04-08-50-007 gives some info on heated
seat but bulletin 03-08-50-014 says that wires chafe under
front driver seat when it moves up and back, then over time
rubs thru. their cure is remove driver seat repair rubbed
wires and reroute wiring harness to opposite side of
bracket to avoid future rubbing. if you are lucky, then may
solve both of your intermittant problems.
I don't know how much you know on the subject of parasitic current draw testing so I will just start at the first step and go on. As always, the first order of business is connecting a parasitic draw tool (simply a battery disconnect switch in series with the battery cable) so you can peek at the parasitic draw without disconnecting the battery in order to place an ammeter in series with the battery. If you've never done this, it simply allows for the cable to be either connected to the battery through its high current switch (so you can cycle the engine / ignition switch) and then introduce the ammeter into the circuit w/o opening the circuit to do so. Just disconnecting the battery and connecting an ammeter often has the effect of causing whatever solid state device might be staying turned on to completely power down and then back up and not draw any extra parasitic current anymore. (or at least while you are looking) Kind of like the police sending a notice in the mail to the
bad guys before they serve their search warrant. No evidence! If you "sneak" the ammeter in series with the cable without disconnecting the battery cable as the parasitic load test tool allows you to do, you will stand a greater chance of catching an electronic device that's staying powered up. Now you simply pull fuses until the excessive draw goes away.
Another very helpful test is performed with a Tech 2 scan tool. If you borrow one to do this test, you may end up buying one as you will like it so well. You connect it to the DLC, go to "Diagnostic Circuit Test" and select "Class 2 Message Monitor". Do this with the key on. You will see what ever modules are active on the bus. Next to the word "Active" on the line with each module, you will see a number. When the is status "Active" the numbers will all be an odd number like 1, or 3, or 5, etc. When you turn off the key, you will see the modules all go to "Inactive" state and the numbers change to an even number like 2, 4, 6, etc. as they go to sleep. Here is the neat tip...with they key off and all the modules saying "Inactive" and having "2" (for example) next to the word "Inactive" walk away from the car. Do something productive like work on some other cars for a few hours/minutes. When you come back to the car, look to see if any module is saying active (it is turned on
when it should be asleep) or look to see if any module's status has incremented. How do you do that? Remember you left them all asleep and saying "2" next to the status "Inactive" when you left the vehicle alone? Look to see if any of the modules' numbers have incremented to an odd number meaning active and the back to the even number meaning inactive. If there is a module with a higher number than all the rest, guess what it did while you were working? It turned on and then turned back off. Remember F.R.E.D.s (Frustrating Ridiculous Electronic Modules) are very devious and rarely act up in front of us technicians! OnStar is the only module that should be turning on and off with the key off. It cycles because it's looking to see if the call center is trying to call it for a door unlock request. This Tech 2 tip is like putting a security camera on all the class 2 modules on the vehicle. Often there are 2 modules waking up...a BCM and a driver door module for example. One
module woke the other one up.
If you are up for some more training on this type of topic, a video I did called "FRED Takes The Bus". It's available through "auto-video.com". I will also be at ASA's Vision 2005 in Kansas City http://www.visionkc.com/ on March 5 and 6th along with dozens of other instructors teaching on a variety of subjects.