Tromper45, That problem DID finally stop occurring, but at the moment, I can't
remember exactly what I did to get it to stop (duuh, I'm getting old, my friend).
I'm usually pretty good at recording, in detail, any and everything that I've ever
done, with any of my vehicles, but I do remember this problem taking SO long to
figure out, that I just wasn't able to maintain enough composure to devote the time
it would have taken to write down all of the different things had tried, and the
results of each test, all the way up to the point of the final conclusion. I DID keep
a scribbled record of time spans and meter readings, and what fuse I had pulled to
try to isolate and identify the culprit that was causing the battery to rapidly and
intermittently drain, and I know that I didn't just throw that stuff away, but don't
think that, once I had FINALLY found the source of problem and corrected it, that I
actually organized it and put it all into that vehicle's repair records file. I'll try to
put my hands on that pile of various scrap papers that I used when I was keeping
track of the different tests I ran, and I will certainly give the matter some ongoing
thought, and hopefully, the remedy will come back to me soon, as I realize that
you are in immediate need, AND I know how frustrating this particular issue can
be, and just how desperate you can become, as your multiple and continuous
efforts to figure it out keep failing. ONE thing that comes to mind (just one of the
many many different things that I tried), now that I'm starting to re-live the
experience, is that I had removed the fuse the "On-Star" system, as it is one of the
items that remains "electrified" for a certain amount of time, even after the
vehicle's ignition key has been turned off (as does the radio, power windows,
windshield wipers (I 'think"), and maybe one or two more electrical accessories),
and will remain "on" or "electrified", until either a door is then opened, or until the
amount of time (predetermined by the vehicle's computer program, usually
anywhere from 5-8 minutes from the time the ignition key was turned off). So,
there ARE a few items that fall under that "stay on" feature, and I tested all of
them, mainly by means of testing battery voltage before and after removing the
item's fuse (or fuses). Now, obviously, if it was the RADIO that was remaining
on, then THAT wouldn't be too hard to notice, because the face of the radio would
remain lit up, even after opening a door, but the On-Star system, or any other
accessory that isn't visibly "lit up" when its on (or "electrified"), would be a good
place to look for this "mystery" item, as possibly being the item attached to the
problem, or at least, attached to (and leading you to) another item that is the
actual cause of the problem. and would STILL be lit up, I was including those "stay
on" items, and wanting to test them first, because, if any of them were NOT
properly being "turned off" by the computer (when a door opened, or the "stay on"
time had been reached), then that item could be continuing to draw current, when
the car is off. As far as the "On-Star" fuse removal test itself, it didn't prove to be
the culprit. I mentioned it here (along with other "stay on" items), because that
"stay on" feature, if its malfunctioning, could very well be causing "something"
under its control of the drain battery when the key is off, AND because, if you're
not registered and paying for the On-Star service, there's no harm in leaving that
fuse out, permanently, so you'll know that it can never cause the same or any
other problem in the future. That having been said, also "think" I remember
there being two fuses that are related to the On-Star system, and one of them also
supplies a different electrical accessory in the vehicle. I can't remember right
now which fuse that was, or what the other accessory was, but I'll try to include
that info, when I can tell you what the final conclusion was (what it was, that finally
fixed the problem). Because the rapid battery draining occurrences were only
happening intermittently, randomly, all by itself, with apparently nothing really
"causing" it to suddenly just happen (nothing obvious, anyway), AND with nothing I
could do to MAKE it start acting up again, all I could do was to wait until it started
rapid draining again, which meant me having to constantly go to the vehicle and
check the voltage reading, hoping to "catch it it the act" and find the voltage
actively dropping. I had initially assumed that it was happening (or when it
would start to happen) was at one of three most likely times. 1 - It would happen
when the car was still running, and/or still being driven, but it wasn't really noticed
then, because the battery was still being supported by the alternator, . . but then,
when the car was shut off and the alternator stopped spinning, but the culprit was
still actively drawing current, THEN the battery voltage would start dropping, and
wouldn't stop dropping, unless the culprit just happened to disengage and stop
drawing current, or until the battery had been drained so low, that it now won't start
the car, the next time the car was to be used, and it would have to be jumped. 2
- It would start to happen AFTER the key was turned off, due to the "stay on"
feature not functioning as it should, as it was not cutting power (when it should
have) to something that would normally only be drawing power when the key was
on and the engine was running, AND that something's normal current draw would
be enough to drain the battery, if left on while the alternator was not supporting the
battery, due to a malfunction in the "stay on" feature, or, 3 - (the most unlikely of
the 3) - Something would, at some point after turning the car off, maybe several
minutes or even hours later, all on it's own and for no apparent reason, start
drawing current a notable amount of current. Once it did this, it may stop on it's
own, just as mysteriously as it had started, or maybe it would continue, until the
next time someone would try to start the car. On the times when I would come
to rescue my wife, and I would find the battery drained down really low, I couldn't
tell if it was still draining, or if the culprit had been "jolted", causing it to let go and
stop drawing current, when my wife had opened the door and/or when she turned
the key on and tried to start the car. The battery was so low by then, there was
no test that I could think of, that would show me any indication of whether it was
still draining or not. Again, at that stage of the occurrence, all I could do was
jump it, and see if the alternator was working after starting the engine (and it
always was). I kept that "jolted" theory on the table, but was never really able to
either confirm or disprove it, even after the problem had been resolved, and the
battery was no longer being randomly drained. Just to confirm, in detail, exactly
what I would do, every time the battery would be found drained (2 or 3 times at my
wife's work, as she was going to leave there and come home), I would grab a
couple of tools, including a multi-meter, drive myself to her workplace, check the
battery and see that the battery voltage was way low (and confirm that all battery
connections were tight and clean), apply jumper cables, wait until the battery
regained enough voltage to start the car, remove the jumper cables and note the
voltage, let it run for a few minutes, then (still running) recheck the voltage and
verify that the alternator was putting out (the wife wasn't going to be, not that night,
but that's a whole nother story, all together), then follow in my car, as the wife
drove home. As soon as we got home, I started "early stage" testing. Before
shutting the car off, I checked battery voltage (still running, voltage was
good/normal), then turned the car off, and check it again. I'd leave the meter on
and attached to the battery, and watch it for changes. Now, even a vehicle with
NO battery-draining issues will show a notable difference/drop in voltage, from
before the engine was shut off to after, and then will slowly continue to drop a little.
I would see this "normal" meter readings every time, but what I was looking for, or
"trying to catch" was a continual RAPID drop in voltage, which was only going to
happen when and if the problem was actually occurring. I never could manage
to "catch" this happening when shutting the engine off, which "would have been"
the "ideal" time to do the troubleshooting, AND the ONLY time which could allow
me to pinpoint the source of the drain. Well, that "ideal" situation never
happened. I DID, a couple of different times, when I was continually going out
the the car to check the voltage test meter, which I left "on" and attached to the
battery, after I had turned the engine off, I actually DID get to see the problem in
progress, by seeing the voltage steadily dropping, however, the couple of time that
saw it, and immediately started scrambling to pull individual fuses and see it the
voltage would stop dropping, the "problem" would suddenly stop on its own, or the
volatge level would already be so low that the accessory(s) attached to the fuse(s)
that I was pulling had already become so unstable (due to the low voltage) that
they were no longer capable of drawing any current. Of course, when I WOULD
see the voltage stabilize (when I would see that it had stopped dropping), just after
I had pulled a particular fuse, I would let out a "YU-HOO!!!", smile big, and add a
"FINALLY!", thinking that I had found the source of the draining. But, after
leaving that fuse out, and digging into whatever accessory(s) were on the other
side of that fuse, I never could find anything to confirm a short or bad component.
I would leave that fuse out, and let the wife continue driving the car daily, while I
would do more research on possible issues with any of the
accessories/components being fed by that fuse, and then usually DAYS later, the
battery would once again randomly drain down (even with that fuse still out), and I
would be back to square one. So, time (and weeks) went on, and more ideas
would pop into my head, one of them being to check into the door-activated
interior dome light system, because they were not only on a constant battery
power source, but were also attached to a timer (they stay on for a few seconds,
after closing the door, or after using the key-fob remote to lock the doors. So, I
removed that fuse, and left it out. There's also (in the
Envoy/Trailblazer/Ascender/Rainier) the tailgate main latch mechanism, inside the
tailgate, that can be heard doing "something" immediately after closing the
tailgate. It sounds like a solenoid or servo motor, and can be heard every time
the tailgate is being closed, regardless of whether the car is running or not, or if
the other doors are locked or not, so it's obviously on a "constant" power source,
and if that mechanism is sometimes "sticking", to where its not completing its
function and then releasing on its own, its possible that it COULD remain
energized, and continuously be drawing current, until it either disengages on its
own, or until is "shocked" into disengaging by, oh let's say, the ignition key being
turned to start, or a jump start, or even by a door being opened. Well, I never
could find anything there either. So, more time, more ideas. Another of those
ideas was the power locks, as they (the lock/unlock switches that control the
power locks) are being supplied by constant battery power, AND because the
lock/unlock switches themselves (all 4 of them, 1 on each door panel) can became
stuck in one position, as if the button was being pressed in and held there, in
either the "lock" or "unlock" position, which would cause ALL of the power lock
solenoids/servo motors (ALL 5 of them, including the tailgate), to ALL (ALL at the
SAME TIME) to energize and STAY energized, which would CERTANLY draw a
BUNCH of current, and easily enough to drain a battery in a VERY SHORT period
of time !!! So, this idea is definitely worth considering and looking into.
It's pretty easy to check for this being the cause or not. The most likely thing
that could cause this issue, would be that one (or more) of the lock/unlock
switches has become, or sometimes becomes, stuck in either the "lock" or
"unlock" pressed-in positions, due to a build-up of some thick or sticky substance,
surrounding or behind/inside of the switch's button. This is typically caused by a
soft drink(s), sweet tea(s), milkshake(s), coffee(s) with sugar, being
spilled/repeatedly spilled onto the door panel and lock switch. Over time, as that
sweetened liquid dries/evaporates, it leaves behind a sticky layer on and IN
BETWEEN the switch's moving parts surfaces, which can cause those moving
parts to "stick" to each other. Repeated "spills" will obviously result in additional
sticky build-up. This sticky build-up on/in-between the moving parts can (and
usually does) cause the switch (button lever) to not release as freely as it should,
once you've taken your finger off of it, and you may be able to feel that move
up against one another need to be able to not being able to so that when can
cause the switch to or short internally, - have an electro-mechanical solenoid /
servo motor the source remaining and therefore continuing to drain current have
switches that AND because they EACH is b then when the engine was running,
to after it was turned off, but by then, there was no longer any rapid voltage drop
happening, just "normal" steady readings at the battery terminals (just a little bit of
"slowly" lowering voltage readings, from the alternator which slowed even more
and no to be whatever had caused the rapid draining, was not the I even started
trying to test anything of these tests, theories . . . . . . . . . . . . . . . . I was going to
send this message, as a "stand by, and I'll send you another message as soon as
I remember what the final fix was" kind of message, but I got pulled away from the
computer before I could send it, and so the message is still here, unsent . . . . .
While I was away, and eventually started looking for my notes on the matter, I
suddenly had one of them-thar "EUREKA !!!" / flashback moments !!!. So,
despite the level of "societal breakdown crap" that's going on in recent days,
WONDERS NEVER cease! If I'm remembering correctly, it was something in
the broken power window (driver's door) mechanism that was the culprit. Once
I replaced it (I bought the entire assembly from a junkyard . . motor, brackets,
cables, cross-bars, etc., all as one assembly),the random / intermittent battery
draining issue ceased, and it never came back. Still a bit of a mystery to me,
since that entire circuit SHOULD have become totally "off-line" and (for all
practical purposes) disconnected from the battery, once the key had been turned
off and the driver's door had been opened (when exiting the vehicle). All I can
figure is that maybe closing the door somehow jarred something into crossing a
connection with the power locks (?), and either the power window motor or the
power lock solenoid would them engage without any means of override protection,
and so, would just constantly pull current from the battery (?) I would have
loved to have gone back in and tried to prove just what was really going on, but by
the time the problem had finally been resolved, I was forced to abandon that
thought, and just move on. Sorry it took me so long to get back with you. My
medical ailments haven't exactly been kind to me, over the past couple of months.
Anyway, if you're still dealing with your Envoy having a random / intermittent /
rapid battery draining issue, hopefully this will help. Good Luck !!! P.S......
Though this was certainly a confusing and frustrating issue, I don't really blame it
on the vehicle itself (Envoy/Trailblazer). I blame it on late-model
unnecessary/overcomplicated/overly-sophisticated engineering. It's all designed
for freaking idiots who can't seem to figure out how to operated a vehicle without
some sort of electronic/computerized assistance. The only other "mystery" type
issues I've encountered (just an f.y.i.) are . . 1) - Poor (Weak) Low RPM
Performance, where the engine runs smoothly, but has no normal "pep", until it
reaches the 2500-2700 RPM range, and then it feels like it's suddenly getting a
50-75 shot of nitrous! The trouble with trying to realize that the issue exists, is
that "normal" driving conditions don't typically put the engine in the 2500-2700
RPM range, so it's easy to say that the vehicle is simply under-powered. This
was the regular expected performance for the Envoy for several years, until the
check engine light came on one day, and a scan showed a retarded exhaust valve
timing issue. The poor low RPM issue had been there, without any change, for
years, but the check engine light never came on until about 6 months ago. The
probable cause was listed as a malfunctioning "_______" (I can't recall what the
component was called) It's a do-hicky that's located on the front passenger side
of the cylinder head, just above the metal gooseneck that connects to the upper
radiator hose. From the outside, it looks kind of like an over-sized ignition
condenser with a 90 degree harness plug attached to it. It controls oil pressure
which passes through it, to govern the valve timing at the timing chain. If you
unplug the harness, and remove the 10mm hold-down bolt, and then pull the
component out of the head, you'll see a long cylindrical thingy, with slots that have
a very fine metal screen inside them. If you soak the cylindrical area
(specifically the screen surfaces) in kerosene for several hours, the blow
compressed air onto the screen slots, then re-soak, and re-blow, and then re-
install the do-hicky, you just may get the same results that I did, which is MUCH-
improved low RPM performance. Even the wife (who NEVER gives it more
than maybe 1/10th throttle), who wasn't even aware that I had done anything,
noticed the Envoy had more "pep". The issue (and the check engine light, with
the same code) did return a few weeks later, intermittently, but the cleaning of the
screens definitely was the right direction to fixing the issue. I'm about to re-
remove the do-hicky, and re-clean the screen slots, but this time I'm also going to
apply compressed air into the cavity that the do-hicky came out of, using an
angled tip on my blow-gun attachment, to try to blowout the journals that are
apparently on the sides of that cavity. According to what I had read about the
issue and that specific check engine code, that screen can and does easily
become clogged (even just a little) enough to cause the variable valve timing to
not do what it was designed to do, and it can really effect performance and fuel
economy. So, if your Envoy seems to be lacking pep, or if it has "less than
ideal" low RPM performance, give this fix a try. The second (and only other)
"mystery" issue we've ever had with our Envoy (which, by the way, we've had
since new, and now has 190k miles on it) is an engine temp gage reading of
basically zero, but the heater is still putting out decent cabin heat (it was NOT
summer, and so it was at least cool enough outside to have the heater on).
Didn't really seem to effect the vehicle's (engine) performance, and it never threw
a check engine light. All I could picture in my mind was a bad temp gage or
sender, or a coolant level so low that no coolant was reaching the sender. I was
told that it was a bad thermostat, but I doubted that. Even if the thermostat had
literally disintegrated to the point of not being there at all, so coolant was free-
flowing trough a totally non-restricted system, the gage should still be reading
something. I've had (many years ago) older vehicles which actually were ran
with no thermostat at all during the summer months, but even they would register
something at the gage. Well, after testing the gage itself, and the wiring from
the sender, I then went to test the sender itself, but it was so far back on the head,
and so hard to get to to test, I asked a few more active late model mechanics, and
they all said "thermostat". So, I replaced the thermostat (which only comes as
an integrated gooseneck hosing with thermostat inside it, as a one-piece part),
and that did the trick. Kind of weird, but that was it. Other than those 2 or 3
oddities, the Envoy has really served us well for the past 13 years and 190,000
miles. Just wanted to offer those good words for the vehicle, in case you're
questioning the worth of your Envoy. Anyway, have a good one, and sorry for
taking so long to get back with you. ChuckLS7.
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