hey guys,its been a while since ive been here,i did a LS swap but anyways, and btw ( the battery was going dead before i did the swap ) lol i have looked every where and seen tons of people are having problems with parasitic drains and a lot are from two places.
fuse # 19 and the bcm which is supposed to never go out.
so since i read every where and dont see it im sorry but need to ask,
2005 blazer 2wd base model here no bells and whistles all manual.
doing the test the only fuses pulled that showed anything were those two again.
so fuse 19 controls 3 things
radio.which is not hooked up
climate control which is manual on mine
instrument cluster.
now while pulling the fuse my needles were dancing around,i could pull the fuse then stick it back in and turn the multi off and i think they would drop back down,i think thats what happened and i had my truck tuned the other day
and he said everything worked but he couldnt get the speedo to work though.hmmm
so if its the cluster on these blazers,whats going bad is it the stepper motor that cost's just a few bucks ?
can a bad stepper motor cause your battery to drain ? thats one question.

second question is if everything inside my blazer works what would be the reason im pulling the fuse and its pointing to the tbc module you know ?
like everyone else i dont want to take my ride to someone else,i did a complete engine swap all by myself and i dont want them messing with it.
i wish these two were related and could kill 2 birds.so should i check for wires under the dash for the bcm or wiggle the connections and watch the multimeter
this sucks.ive got a huge stereo waiting to come in.anyways if you feel like it,thanks i do need help and i did read tons before posting.
oh and with key off,my gauges arent all down low where you would think they would be,not sure if its normal,just thinking of everything,ok,byeeeee

 

the problem with forums,is people come and people go,they come and ask questions,and people SOMETIMES help with ideas like try this try that,it might be this or that and the guy is like ok i will try that,then he reports back that wasnt it then people suggest other ideas,and then poof,,the guys gone,they never ever come back on any forum and tell what the problem was so that people in the future reading can get use of this.

so i bought this blazer and it sat and the battery kept dying so i thought it was a junky battery and when i did my LS swap i would do away with everything with good parts and i did but the problem is still there so its not my work its the blazer,do yall know,it had 180 thousand miles on it and still had the original air filter in it lol,yep so anyways my brain is fried i give up,its the holidays im tired of trying to figure out problems so im taking it to a shop tomorrow.

but i will have the decency to post what it was and the problems i was having,incase it can help someone later on.cause im that kind of guy.
god i hope its not a major problem.oh well i will just pay.

 

Finding a power drain on a modified vehicle...
...good luck with the shop.

A word of caution: Give them a limit price until which you are willing to pay, else it will be a bottomless pit.
To figure a drain in a heavily modified car like yours is a nightmare in itself. Most probably nothing is documented so you have no clue as on how it all fits together, now guess what the shop will do.

You never said, if pulling the various fuses actually did stop the draining of the battery at some point, or i got lost in your sentence(s).

• To figure these problems you have to first isolate the circuits (wiring diagram) to make sure it does get power only from one source, then methodically pull the fuses using a high quality multimeter to measure the changes in voltage across various points.
• Then remove all components from the system which are not required taking extra care not to forget any plugged in appliances which you or a previous owner may have installed somewhere in the system. I.e. amplifier spliced into the interior light circuit or any other service directly on the battery power, such as a phone charger plugged into the aux 12V plug.
• In addition make sure all door switches work and actually do switch off the interior lights. Also check sunshades mirrors if equipped with lights, glove box, trunk light and light under the hood.

These cars do some weird switchings between the RUN and ACC and OFF position of the key. Several supplies are switched and a circuit may get it's power from a different source when switched off vs. running engine. To further complicate the problem some of the control modules go into sleep mode only after a lengthy period (30 min) and your measuring equipment needs to be in place in such a way that no door has to be opened to check.

A bad capacitor in a radio can cause a drain as can other things electronic or electric. As you state you are into stereo systems I would unhook all of that as a first and start from there.

It is nice if the OP (original poster) comes back and completes a thread with a solution. Fortunately we have many which do exactly that.

Good luck with figuring your power drain.

 

well i dropped off my blazer wed/morn.and they called me today,monday to come get it,they said they couldnt find anything and that it held enough juice over the weekend to crank it this morning,and didnt charge me anything,but also they were like 10 cars behind and today it was packed with cars and people,i guess people are getting ready to go out of town or something i dont know.
so im back to square nothing.
parasitic test.pulled all fuses on blazer that has been sitting and not running for days,so sleep mode should have been where it needs to be i guess idn.
base model so no lights above mirrors,or electric doors or windows
i pulled fuse 19 the fluke multi dropped with head unit hooked up,but i didnt have the remote wire hooked up to a ign fuse.
did notice this,i unhooked head unit,then pulled fuse 19,nothing happened,but when i put fuse back in it drops on mm.ive never seen on videos what that means,so i dont know,
fuse tbc drops the mm amps as soon as i pull fuse.
oh they said they ran a amperage drain on it and it was normal.and i had my head unit unplugged,so this sucks if its a radio problem considering im installing a 18 inch sub
guess i will pull fuse 19 every time i park it,i drove it home and it was 12.63 v,five hours later its at 12.52 v.does this sound normal,ive got two yellow tops brand new,only one is hooked up right now though.
i can buy a battery trickler
i can maybe see how much a house call mechanic costs
speedometer still doesnt work,weird thing about that,driving down the rd i can push in the clutch and the speedo needle thats on zero will rocket to pegged out then back to zero,not sure why it would do that
i installed the entire engine and wiring harness but im stumped on this one guys,im not a pro at reading amps.i will post back when i get something,anything fixed.
super bummed out.

 

update on looking for gremlins
i unplugged my gauge cluster and cleaned it then reinstalled it and i had a multimeter hooked up
it dropped for a couple seconds then went back up,so with my pioneer unplugged the only thing left on fuse 19
or so im told is the climate control,hvac.so i unplugged it last night and came out this morning and checked the meter and bam it read the same thing
no voltage drop.so it looks like its my hvac.
i hooked my pioneer head unit back up and im going to let it sit over night and check it,but i can already tell i think its going to be the same
voltage,i hope,i hope i didnt just jinx myself haha
also its not blowing hot air,dont know if its related or not,but dont care right now,just happy i finally found something.
the only things that dont work on this deal is my speedometer and my heater wont blow hot air,just blows air,but i will figure that out next.
i guess im going to just buy a new hvac.idn yet

question,since im not familiar with this vehicle,on the hvac controls,it has the fan switch with numbers 1-4 then the next switch is hot or cold then the next is the ac
with off,acc,max ac then vent settings
does it have to be set to a vent setting for the fan to come on,when i just turn the fan switch nothing happens unless i have it set to blow some where the vents or floor or defrost etc,is that how its supposed to work ? its different in my z71 thanks

 

damn its cold this morning,burrrrr so i went out in the garage and turned on the multimeter which im tired of typing that word,so from now on its MM and i was like ok lets see,and it was at 12.45 all day the last two days with the hvac unplugged or half way unplugged and i plugged in my h.u. last night and its 12.44 so im happy.plus i have another battery in the back thats not even hooked up.two yellow tops and a 370 amp alt,so my next step is to figure out why the hvac is dropping volts and i mean like over night it would go from 12.48 to 12.45 that much.now its stable.
any ideas what to test or should i just buy a new hvac guys ?

 

the heater,well i stumbled upon the vacuum hose under the hood,i found the hidden nipple on drivers side fender haha,and then the hose comes from some where in the front under the abs mod,wheres does it come from,and then at one time it would have went across the brake master cylinder to some place,since my v6 is gone where did that connect to so i can figure out how im going to make something,they might already have something built but i dont know what it would be called.
so its the hvac vacuum that controls the heat and ac,it has a T and had a vacuum valve at one time and this is all ive got so far.lol
well merry christmas its 11.09 xmas eve

 

well ok,so it sat at this electrical shop for 4 weeks,i was pissed.i told them where the drain was coming from and that my speedometer didnt work.when driving i would push in the clutch and the speedo needle would peg out then go back down.we ended up talking to current performance the folks that built my wiring harness and they told the people at the shop that it was one wire,so then they replaced my gauge cluster and now i have to drive back across town to where i got it tuned so they can set my speedometer for me.so something so simple turned into a big deal.it was one wire.and truth be told the cluster was probably good,well i know it was,it worked when the 4.3 was in it,but i only drove it one time,but it worked then.so thats what it was in my case

just wanted to let people know incase they were reading and trying to solve a issue of their own.i guess the one wire on the harness wouldnt let the gauge cluster go to sleep so it was draining power by staying up all night pinging back and fourth.so a thousand bucks later and no speedometer hopefully the tuners can make it work,