New to Blazers.

2001 Blazer, 89000 mileswith all the bells and whistles including ON-STAR.

Will leaving the key in the ignition cause overnight battery drain?

I have replaced the battery. Hooked an ammeter between ground cable and battery. After about 20 min, current drawdrops to.020. (20 milliamps) According to Alldata/diy this is normal.When the battery cable is reconnected to battery, it will drain overnight. It isdriving me nuts. I don't know what to do next. Does anyone have advice/experience they would share? [X(]

 

No, leaving the key in the ignition will not cause a battery drain, provided it is in the OFF position.

Have you had your battery tested?

 

Battery is 3 days old. This is the 3rd battery that I have tried. The battery hold its charge unless it is connected to the blazer. Anyone else?

 

Any accessories left on?

In the dead of winter, I MUST unplug my radar detector, or it usually won't start in the morning. The rest of the year, I can leave it plugged in.

 

Similar symtomto whatI've just had! Check that your seat adjuster lever has not broken & is pushing down on the toggle for the seat forward/backward movement. That cost me $636.75 at an auto elec shop to find out.

 

Did you figure out what was causing your battery to drain? I am having the same problem.

 

still have your drain? I noticed on our 2001 the mirror lids on top of sun visors were not
closing tight enough to shut off the 4 lights in mirrors [2 in each one]. they where actually broken. i put black duct tape on both edges. once it is warm enough i will put velcro on opening edge and leave duct tape on back edge to act like a hinge. check at night see if you see light coming out edges even though lids are closed on mirrors!! if this is not your problem good luck otherwise.

 

Same problem with the MIR/LKS mirrors / locks fuse showing 60 + mA drain and climbing. Taped the mirrors so their switches were off, still a drain in that circuit, about the same fast rise in mA.
The driver's side front door lags down seriously toward the rear of the vehicle. Prob doesn't seem to be in the hinge. Can this be the problem with this fuse? Had to replace the battey last week, usually leave the battery unhooked until finding the parasitic drain.

The only other draw is in the ECMI fuse, hope this doesn't mean replace the Engine Control Module - Injectors. Heard that's about $150.

Tradeoff is fix the problems causing the battery drain, or keep paying $130 for new batteries. Familiar with a lot of the usual car repairs since 1950s, few electrical problems before. Any ideas?

 

I had the same problem on my 98 Blazer after I bought it 3 years ago or so... I found that both visors were not shut completely causing the little visor lights too stay on which was killing my battery...

 

Thanks - this forum makes me know I'm not HOME ALONE like the movie. The Blazer started bottoming out the battery about every 6 months last year, then it got more often, now it drained the battery so much the experienced garage man said he sever saw a battery that dead. The gradual change may mean a wire or something gradually wearing through the insulation. Only could be charged to 400 CC volts. Gor a new battery. Batt. lost a third of a volt overnight - huge. Today I got a batt. disconnect switch, am charging it up. The owner's manual or internet shows the codes, like MIR/LKS which is mirrors/locks.
The driver's door is sagging down a half inch or more, so when you close it the door has to move up. This could well be the prob with this code. No bulbs in the visor lights, but under the prior owner the wires there may have been changed around with a resulting short. No light in the glove compartment.
Have used the little tester that comes with new fuses, gets around pulling all the fuses and relays to at least see where the draw is at fuses. Be very careful checking around the starter, believe that's an always hot wire from the batt. Alternator may have shorts as well as the started, but I believe these you check later.
Got a Haynes auto ecectrical manual, expected to see a good explanation on how to find parasitic drains, nada. Hard to find any complete info about it. Possibly since garages make a ton of money out of parasitic drain that the manual publishers in some way don't give us much info on it. Just found what looks like a good guide at last:
http://www.aerolithium.com/parasitic_drain_info.pdf from an aircraft source. Looks like I've found the 2 fuses with the prob, if the solutions aren't evident by Monday, it goes to the mechanic. Got the weekend. I'll let the forum know what the solutions are. Thanks again.