Battery drain

[Armada]

Yesterday I replaced the original fuel pump in my 1009. I started the blazer and ran it for about 10 minutes, then shut it off, no problems. This morning I went out to start it again and noticed the oil pressure light was on along with one of the gen lights. WTF? I put the key in and turned it over and the starter only clicked. Low batteries. The idiot lights were all off last night when I turned the truck off.
I diconnected the batteries, and they are on the charger right now.
I had the gens totally rebuilt over a month ago by a shop that only specializes in gens and starters. My guess is the ignition switch on the column shorted for some reason. It did seem a little harder to cycle the lock cylinder. Any ideas?
I hate electrical problems.

 

[Taz]

I have to wonder if the "rack" that couples the lock cylinder to the rod which transfers motion down to the ignition switch is broken. I've seen this problem mostly in tilt columns, but it is possible in non tilts as well.
To simplify, when you turn the ignition cylinder to the off position , the linkage does not slide the ignition switch all the way to off. My clue is that you said it was harder to turn the key. Good luck, Gary

 

[Armada]

I can feel the rod move on the column with my hand when I cycle the key, and the start and run position works correctly. It just won't shut the ignition off when the key is turned to off, which leads me to believe it is the ignition switch,unless something is shorted under the hood. Could the gens short?
Did I tell ya I hate electrical problems?

 

[Taz]

I think I would drop the column down, remove the ignition switch and test it by moving it manually. You should be able to feel a detent for each key position. If the rod falls out of the column when the switch is removed, then the rack is broken and the fun begins. Tearing into a steering column can be a real pain. If the switch does not function correctly, you found the problem.

I have seen the rack crack which makes the rod longer and messes up the adjustment of the ignition switch. The switch is adjusted by sliding it on the two bolts that hold it to the column, tigtening it down when it functions correctly. If the rack has indeed cracked, it is just a matter of time before it breaks clean. It is made out of pot metal.

That is what I would do. I still think you might be on to something with you catching that the cylinder felt different. Then again, it might be something in the switch. I personally have never had to replace a GM switch, although I have repaired a mess of columns with broken racks. Good luck

 

[Armada]

Thanks. I'll tear into it today, let you know what I find.

 

[MATT]

Before you tear it down, get a DVOM and set it to amps. Disconnect one of your negative battery terminals and hook the amp meter in series with neg bat post and the cable. This will measure parastic draw on the bat. Normally a good spec is under 70mA. If you have more than this, try to disconnet the electrical connector for your ignition switch and see if the drain decreases. Careful not to blow your fuse in your Volt Meter/Amp meter! Hope this helps.

 

[Armada]

Sorry, looong post.
Update and new issue. I hate electrical problems!
I never did have a chance to trace the wiring to find the drain on the batteries, however, it was not the rack in the steering column or the ignition switch. I tore down the steering column when I put in a new lock cylinder asm. and cleaned and lubed all of the column. I swear, half of the desert came back in that truck.
Anyway, while I've been working on it these last few months, I would just keep the batteries disconnected and only connect them when I needed to start the truck to move it. When running, the gen 1 light would go off, when shut off and key removed, it would stay on).
I drove it this last weekend (about 25 miles) and half way home the gen 1 light came on, and this time stayed on. Except now when I shut the truck off and remove the key, the light goes off and stays off.
I pulled the no. 1 alt. this morning and took it back to the shop that had rebuilt it. They tested it, not working, bad rectifier. He said the only way they go bad is if the polarity had been reversed on it, even for a second. It had not. I installed it correctly. Remember, everything worked fine for awhile after rebuilding the alts.
Is there anything else in the elctrical circuit that could cause, a parasitic drain, and then cause the alt to go bad??? I don't want to put the alt back in only to have it eff up again. Can any of you electrical wizards enlighten me?
Did I tell you I hate electrical probs?

 

[dilvoy]

Could someone in the past have replaced the #2 alt and mixed up the wiring on it?

 

[Armada]

I got it when the government released the vehicle. The wiring is correct. Anything is possible but I doubt it. When I had them both rebuilt, they had never been 'opened' before. The condition of the alts corresponded with the milage of the truck as well, which also leads me to believe they were original to the truck.

 

[m35a2cowner]

Battery draw

You know, new electrical parts do go bad every once and a while. It might not be anything you did. The guy at the alternator shop might be covering his tracks. I have not worked on any military blazers but I have worked on a few civilian ones. I have seen the thing with the dash on other vehicles, if that happens again try disconnecting wires from the alternator to see if they go out. It might be a symptom of a bad diode (SP). In automotive school we were taught to put a 12 light in series with the battery and the cable if it lit there was enough of a draw to draw down the battery. If it lights up disconnect things one at a time to see if the light goes off. Try the alternator both the plastic plug and the battery wire. When it does you have found the draw. Try all the things that operate with the key off.

 

[Armada]

Put the re-rebuilt alt in today. Good news is it was still covered under warranty. All systems go. No more lingering gen 1 light when key removed. The short must have been in the alternator itself. We'll see how long it lasts.
I hate electrical problems........

 

[Desert Rat]

Armada,

Me too, they're SHOCKing, reVOLTing and always trying my CAPACITY, giving me RESISTANCE!!!! I'm DRAWing on experience.

 

[Armada]

You need to be unplugged....