Hi all,

I'm in desperate need for help. I have a 1983 Chevy 4x4 with the 6.2 diesel. I am having horrible problem with the batteries going dead. I have changed the alternator which went out, the starter which went back, been through three batteries that went bad in a matter of a month. I installed a switch to where both batteries are connected to one another, then to the switch. Coming off the switch, I have it running directly to the starter. Even when the switch is off, my batteries are still dead. They are the Wal-Mart Ever Start with 900CCA I believe. How can this be? Could the batteries i'm getting just be junk? What could be pulling so hard that it's draining the batteries so quick? My alternator shows 12-13 volts like normal. Please help! :help:

First, you must check the system for electrical draw. Disconnect both batteries, connect a test light (for a "quick check") between one negative cable and touch the probe to the battery terminal. If the test light lights up brightly, you have a draw on the system. If it glows dimly, it's a normal parasitic load. This comes from the voltage regulator, etc.

If it shows a draw (bright light), it's time to get serious about finding it. Begin by removing fuses, disconnecting accessories, etc. until the draw goes away. When you find the circuit that eliminates the draw when unhooked, trace that circuit and repair the problem. It may be something simple, like a grounded wire or a glove box light left on. It may be something more complicated, like an power relay sticking in the "on" position, even with everything shut off. I've had power seat/window relays stick on, etc.

The voltage, when checked with an external meter at the battery, should be in the 13.8 to 14.2 range. That's with engine running, warmed up, all accessories off. If the output voltage is much lower than that, I would test the alternator on a load tester to varify it's output. Bad batteries can make an alternator "look low". Be sure to check belt tension, if you can rotate the alternator pulley by hand, the belt is slipping! Loose, slipping belts cause more dead batteries than anything and the early 6.2's were very prone to loose, fast wearing belts. The belt tension needed to be adjusted frequently.

This is just a start, if it gets too deep, I would suggest a reputable electrical shop if you can find one. Most general repair shops don't see electrical problems often enough to be able to quickly diagnose this type of problem. It can be time consuming and, as you know, time is money. Good Luck

Thanks for the reply. I'll try that. It just seemed strange that even when the switch was off, the batteries were dead within two days. However, when I get it started for the day, I have no problem. Electrical issues are so frustrating, but i'll :grd: .

I have my two battery positive cables going to a bus bar that I mounted on the right fender. The starter cable is attached to the buss. The second post on the battery bus has the alternator charging cable attached to it. The power wires for all of the truck and camper circuits are also attached to the second post. Each battery has a ground wire going to the engine block. All of my battery cables (positive and negative) are very heavy cables.

It may be that your batteries aren't getting charged due to the setup that you have. Both batteries should be charged at the sme time. I would not have that switch.

If you have a good voltmeter then it should resgister almost 14 volts for about 20 minutes or so and then start tapering off to about 13.5 volts. If you have a v belt alternator pulley then you should have a 78 AMP alternator, not a 94 AMP unit as they will slip (at least from my experience). The 78 AMP alternator that I have keeps my two truck batteries as well as my camper battery charged. And I have the same Wal-Mart batteries that you have.

Right on Cougar, I have a similar setup on one of my vehicles. Sure makes testing, adding accessories, etc. easier!

All of my battery cables (positive and negative) are very heavy cables.


thats a big difference there. when I first got my truck, it had skinny battery cables, and the one positive that joins the batteries had a screw type splicer that joined a different size cable! :eek: It caused all kinds of charging and starting problems, even after I replaced the cables...dead alternator and weak batteries from dieing and stuff. went through 2 alternators working things out with that and the junk belt.

But..before I could get to the cables...I went to start it once. started turning over then just stopped. lost all power. poped the hood, and look at that, it blew off one positive cable off the post, damaging the battery terminal. great..but lucky it didnt seem like it was leaking or anything.

that was right before taking a trip far far away. months later I come back...and theres white powder all down the battery from the terminal and on the tray.-:t

Any auto parts store have a bus bar? If you get a chance, give me a link of what I need to be looking for.

Also it sounds like a plus cause I have a fuel tank in there for the farm. I'd love to get it out of my D-Max and stop using it as my farm truck.

I made my own heavy duty buss bar. I cut a 2 1/2 in. X 5 1/2 in. X 1/4 in. thick piece of phenolic and mounted it on the fender well with 1 in. solid rubber mounts and 1/4 in. bolts. I installed two bolts thru a copper strip (a flattened piece of copper water pipe for the buss bar) for mounting of the electrical connectors between the two outside bolts. I used a 3/8ths in. bolt for the battery and starter cables and a No. 10 bolt for the other electrical power wires going to the cab plus the positive charging wire from the alternator. I put a washer on top and bottom of both buss bar bolts and then put a nut real tight so the nuts/bolts wouldn't turn when I put the terminals on and then fastened them down with a washer, lock washer, and a nut. The 1 in. rubber mounts keep the buss bar bolt heads off the fender so you will not short out. I put some heavy rubber tubing over the battery and starter connectors to prevent them from shorting out to the bolts mounting the board to the fender. Vinyl tubing could also be used if you don't have heavy rubber tubing.

I wish I had a way of covering the assembly to prevent any accidental shorting out from using tools in the area. There are a lot of amps on that buss bar, but it sure solved my problem of hooking my batteries together plus providing a post for my other truck power requirements!!!!

My truck came with a small electrical mounting block on the left side firewall that I also use. One of my 8 or 10 ga. wires go to it from the buss bar and then I have several connectors taking power from that terminal. That way I don't have to route all of the elctrical wires to the home made buss bar on the fender. I finish off the wiring with spagettii (wire loom) covering to keep the wiring together. It works for me, but that buss bar is HOT with a lot of amps from those two batteries. I wish I had a cover for it!!!

The one I used came from my local NAPA store. They are a "farm store" so can purchase from other vendors as well. They're not stuck on any brand name.

Mine has no cover, but has standup legs on the corners as well as two in the center. They stick up about 1 1/4" above the mounting surface. (Like a table turned upside down with the legs sticking up.) It keeps stuff from accidently touching the terminals but lets the wiring lay flat and come out in any direction.

The bar on my daughters '76 Nova is red and has a plastic snapon cover. I have no idea where it came from, but it's what you're looking for. I's start with an electrical catalog from your local parts store.