I have posted here before concerning this situation and I'm done. It goes to the mech next week and I told him to keep it until he figures it out.

I have replace the Alt and Battery (Life time warrantly). But I still have the same problem.

Oh by the way its a 2000 Blazer LT 4x4 with 106K on it, yep have 106K on it a yr ago.

There is no drain on the battery where its shut off. But, When I start it things start to happen. The volt meter shows 14.4 or theres about. I can hear the Alt humming. I turn on the A/C a slight drop (I'm sitting in my drive way not driving it) thats okay and expected. I hit my turn sigs and the volts drop to 13.8 and never recovers (Never goes back to 14 volts no matter how long I let it idle. Again the Alt is humming away.

So I take it for a short test drive (To get a pizza) I choose the one that is about 5 miles away just for the test drive. I drive there with nothing running, no A/C, Radio, etc. I don't use my turn sigs. By the time I get there to get the pizza the voltage has drop to 13.8 again (Go figure) and the Alt is humming away (Keep in mind this is a new one along with the battery). When I get home the volt meter still says 13.8. I turn it off and let it set all night and start it up and voltage is 14.4 again! (Again go figure). Just for ****s and giggles I put the battery charger on it for 12 volts deep cycle, it takes about 30 seconds and the green light comes on, its fully charge!

I hook up another volt meter straight to the battery and it stays at 14 volts and never drops. (again go figure).

Bad volt meter inside the SUV? Short or bad ground in the turn sigs? Something is drawing the juice but only when running. Maybe Starter drawing the juice? Its OEM and never change. But something is drawing juice when running and I'm done with it...I won't trust it to go out of town, don't want to get stuck along side of the road with a dead battery.

So off to the mech who had the proper knowledge and testing equip that I don't have or don't know. I am the 2nd owner, bought it in 2002 and its a 2000. So I know the vech and my gut says something isn't right. Also had the fuel pump (Yea I'm that guy) replace at the 700 plus bucks, but its starts right up now, put the key in the ign and it fires right up and runs perfect. Oh, also tried wiggling the ign to see if that does anything. I did it while the charger was on it and the engine off and I did notice the voltage change on the charger from 10 volts to 15 volts, my mech said that should be because when I do that it trips the security system and its normal. But, he will give it a fine tooth comb when I take it there.

Have I miss anything?

Thanks

 

Starting in 1999, the alternator is controlled by the PCM, (powertrain control module). It applies PWM, (pulse width modulation) to excite the field in the alternator. Here is a "work around" to retro fit it to 1998 and earlier. The modification uses the ignition circuit to feed the voltage regulator, a far more stable & reliable way to maintain constant charging voltage: https://blazerforum.com/forum/lighti...ference-53055/

 

Thanks will give it a shot.

 

Well took the Blazer to my mech today. I ask him to step outside I wanted to show him first hand what was going on. I said when I left my house to come here the votage read 14.2, it now reads 13.9. I then said hit the turn sig, he did and the volt meter drop even more and I said and it won't come back to 14 as long as the Blazer is running. He hit the gas and ran to 3,000 rpm and vote gage didn't even blink...He said that ani't right, I said thank you very much...its all yours to fix and I gave him the print out of how to change that plug in the back of the Alt if he thinks thats what it needs. Told him to take his time and do it right...
We shall see...

 

Keep us posted, let us know what is done to fix it.

 

Will do.

 

Gave my mech a call today to see what he has come up with. He said he has been very busy and hasn't had the time to give the Blazer a good looking at, but, so far he really can't fine anything except he think the idle is a little off by 100 rpm and that could be the computer. He did say he check for for shorts and bad grounds and just can't find anything yet. (He also mention I might be over reacting, I said I don't think so, I know my Blazer inside and out and it ani't right) I told him the volt meter has Never acted like that. I also ask him if he press on the gas and made the rpm's 700 while in gear what was the reading and he said it was fine at 14 volts and held it. I then ask him what happens when he hits the turn sig's? He stop and I heard silence...Hmmmmm. I ask him if the voltage drop and if it did even at 700 idle in gear did it recover back to 14 volts and he said NO!
He then went on to explain that the volt meter itself might be bad and that he is pretty sure with my yr of Blazer (2000) the meter are electrical (sp) and thats what might be bad. (Something about a electrical moter within the meter). I said okay can you replace that? He said he knew of a place (Didn't know if they were still in business) that you can swap out the volt meter for they rebuild them but they weren't cheap like 200-300 bucks. I told him about the ground for the turn sigs being under the fuse box under the hood and he said he has never heard of that (Got that from this site) and that he has check out the fuse box for shorts or grounds and everything is fine there. He mention about cleaning out the throttle body and I told him I had already done that but he is free to take a look at it and see if I did a good job plus I had the fuel injections flush out by a professal about a yr ago also.

I think I might have him change that plug in back of the alt (seen and printed off on the thread on how to do it and put it in the Blazer). His work load has kept him pretty busy so I understand and am giving him the time to check it out real good.

So he has no real answer as to why when the turn sigs are turn on why the voltage drop with no recovery and why if I just drive the Blazer the votage goes down. Also keep in mind there is no drain when the Blazer is shut off as a matter of fact let it sit over night and start it the voltage reads 14.2 and we start the drain all over again...This all started when the fuel pump started going bad. Since then I have had it replace, the Battery replace and the Alt replace. It did seem to get a little better after I replace the battery and alt, but not that much better and its still doing it.

Any thoughts?

 

Date: 8/22/2012, Still no word from my mech. I was over there last Thrusday and I wanted to take the Blazer for a spin (25 miles) and see where the vote gage move to. Mech did want me to do that and he wanted to check out a few other things first. I think he is at a loss as to where the problem is. I keep saying ground, ground, ground...and now I'm thinking instr cluster panel. Thats all thats left I think...No drainage what so ever if the suv is not running, problems start only after it is started. So there is no short, that leads me to being a ground or maybe the cluster panel is bad or not grounded.

I'm getting ready to take it back and put a For Sale sign on it...Darn good looking Suv, Every thing works 4x4 LT (and the 4x4 works) New Alt, New Bat, tires good. inside is not tore up. It runs great except for this problem and I'm about ready to give in and can it. Enough is Enough...It beat me this time...

 

8/23/2012, Call my mech again today to see where he is at with the Suv. He said he has it kind of torn apart at the moment. He said he is trying to find out why the 175amp fuse wire is running hot and losing 1/2 volt. I again suggested "Ground". I think he going to charge me storage soon...hahahahahahahahah....He better get it straight soon, wife has to go back in the hospital the middle of next month for another surgery on her broken leg, (Its not healing) then I have my own doc appointments (VA and Clivilan) coming up.

 

Well, Pull the vech away from the mech, he is stump. I did pick up on ebay this nefty little gaget that you can plug into you cig lighter slot and it reads the voltage. Try it yesterday for the 1st time. 1st start---14.3 volts, after that it was all over the place, the voltage would jump back and forth between 14.3 and 14.2 until I hit the good old turn sigs and it drop to 13.8, but did recover back to 14.0, then back down to 13.8. Also there was a drain on the system when I kick the A/C on. At first no effect until I turn the fan on the that help drawn the votage down to 13.8 then it was a fight between 14 and 13.8 volts and it stayed pretty much that way until I got home. When I shut the suv off the volts drop to 12.5 before I pull the meter out of the socket.
I still think there is a ground problem and I think its in the turn sigs. Can anyone tell me where the ground is for the turn sigs and suggest where a good spot for an extra ground for the turn sigs can be applied?