I have a 2000 Blazer LT 4x4 4.3 with 106K on it.

Now this is a first for me. I have already replaced the Alt and the Bat within the last week.

Today when I started it up it ran fine, the volt meter was straight up and little to the right, as expected, everything go to go so far.

The I turn the A/C on and volt meter went to the left of straight, When I turn either one of the turn sig on the volt meter goes left to right a little as the light blinks.

Now for the closer; When I give gas (Park) around 1700 rpm all of a suddent the volt meter went way to the left and the rpm's drop by 500 or so, then pick back up and it did this all the time with me giving it gas. I turn the A/C off and I see no problems.

Whats wrong?

 

i would check all your connections in the starting-charging system positive and ground side. maybe something is loose and or corroded. did this just happen since you replace the alt?

 

Same thing happened to me a few days ago. I'm still looking for a solution. It hasn't happened since though, and I never messed with the alt or battery before it happened.

 

clean your grounds good

 

Thanks for reply's.

1st answer, yes it first started after I replace the Alt and Bat didn't do it before but I did have problems with the volt meter inside the car showing discharge once I started the Blazer and really got worse after I change out the Alt and Bat like as I stated in my first thread about this problem. I did have a problem with the neg ground on the battery when I put the new battery in. I do believe it got cross threaded but I thought I had clear the situation up with putting a nut on the end of the bolt to the battery (Cable) and working it to get a good thread again and but a bolt in the battery terminal and ran it (Tighted) it back and forth a few times to get a good thread going again. But I notice that the bolt still would not tighted without a lot of force so maybe the problem is there. I just might get a new cable and install it and see what happens. Or at least a new bolt.
I know through experience that the battery cables on the side mounted cables can be a pain in the butt at times. One time (Many yrs ago) I was coming home from one of my VA appointments in Phoenix that the Blazer would just shut off (Kinda nasty going down I-10 where the traffic is hauling butt) I had to pull over about a dozen times and wait for about a minute and it would re-start and I would be on my way for awhile then it would do it again. When I finally got home I check the battery cables and did a re-tighten of them and the problem went away. So I think it might be there. I also just might take that bolt out and replace it with the bolt I use to re-thread the battery cable on the battery it fit real good but has a 9/16 head and little differnet from the 5/16 head on the reg battery cable, but heck it works I go for it. Plus there are two grounds on that cable, I have found one so far still looking for the other one. But I will take them off and clean them up and see what happens.

Thanks all for your reply's.

Well, clean and check everything and it is all good, but still have the same problem. I know when something electical goes its a beast to find. But, I must admit in all of my 64 young yrs, I have never seen a volt meter (In the vech) when the A/C is on only (so far) take a dip and the rpm's take a dip at the same time...thats a new one on me. Took me 1 1/2 hr to recharge (deep cycle 12 volt) the battery this time and it is a new one. Took me about 2 mintues when I brought it home and put the charger on it first before in the vech (Just me and my ways). So it was being hit pretty hard with a discharge..I don't know?

 

Have a question. Underneath the battery box lies your 4x4 so and another black box with the Pos cable going in and the Pos cable going out and what it looks like a resitor (sp). in between. I could not get all the way open because of the 4x4 so in the way. But I did do a continually (sp) test on it since the battery is out and the numbers were jumping all over the place from a low of .86 to a high of 5.36. Now maybe my hands were a little shakey being 9 am and all..But what is this thing? And could it be the cause of my problems?
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Okay folks; Here is the latest. My muti-meter was bad. Went up to H. Depot and pick another one up and did the tests on the item in question. It came out 0, so its good, I also tested the light under the hood (Because it seem to be staying on longer then before) It tested 0 also. Test my A/C plug (The one that plugs into the A/C under the hood, also no battery in car) It was not so good had a reading of over 5, so that could be one problem, the other just might be in the turn signals, when the car is running and I put either one on and the A/C on the volt meter moves a little both ways and the volt meter does not recovey from that.
While I was at it, I test the new battery while the car was running and got 14.53 volts and the same with the Alt. But, After turing the A/C on it drop to aroung 14.40 volts and after turing on the turn sigs either way the battery volts drops to around 14.3 volts, so I'm still losing juice somewhere. Now the Alt is putting out 14.5 the whole time but the battery is losing.
Maybe a ground in the turn sigs? What about the A/C plug the cont test show a 5 something, bad wires or a ground again? And where do I start to look?

Thanks, Oh by the way, so far no drop in volts or rpm's this time after I clean the grounds up for the Neg cable.

 

its the main fuse and splitter between bat-alt-fuse panel. could have some corrosion in there. un bolt the 4x4 act thru the psg wheel well and you will be able to pull it out and have a look.

 

Thanks for all the reply's. I think I know the problem since I fixed the grounds and no more (So far) Voltage drop and Rpm's drop.

My lowest reading of the battery while running is 14.2 and the Alt around 14.3, 14.4. But yet my volt meter inside the Blazer shows on the neg side of 14 (A little to the left maybe a 1/2 tick) Now after setting back, having a beer or two, it dawn on me the volt meter inside the Blazer is going bad. If the battery shows 14.2 while running that volt meter should be dead center or a little to the right. Its not! That leaves me to think the volt meter itself is bad. Any comments? Now why when I turn the turn sig on the volt meter moves back and forth maybe a half click. Now that could be another ground I haven't found yet. Where would I check the ground for the turn sigs?
Thanks

 

Well,

Went and bought a cheap volt meter like the one you can install inside your car.

I rig it at first (Just for shi*s and giggles) to hook straight to the battery and look at it before starting and after starting and after engaging some items ie; The A/C and the Turn Sigs.

Before start it read around 12.5, after start 14 volts straight up. Look at my gage in the car and it said the same thing. Engage the A/C still 14 straight up on both gages. Hit the turn sigs, the one hook straight to the battery still maintain 14 v. The one inside the car dip to about 13.8 or 9 depends on the way you look at it.

Put my mutimeter on the battery while running and said 14.3 and the Alt 14.5 so the Alt is working all the time to keep the battery up. I thought I read somewhere on one of these post that the Alt should be reading at least in the 14's and desirable would be 15v.
But on remaf ones it very well could be in the 14's and thats what I have. I have a life time warrt with Autozone and this is my 3rd replacement in as many yrs (3). When you get something out of China or Mexico thats what you get!

But, I still would like to find the ground for the Turn Sigs, Any Ideas?

Thanks