View Full Version : Engine won't crank over. Smoke coming from pos. batt terminal.

06-25-2013, 09:52 PM
A little background-
I am somewhat mechanically inclined... I am learning and doing everything myself to save money. I joined the marine corps after high school, and my job takes up most of my time. Therefore, it is a slow learning process. Point being, excuse my naivety!

I posted the specs of the truck I bought about a month and a half ago. Link- http://www.gmt400.com/forum/showthread.php?18997-My-Blacked-Out-89-1500. I have done so much to this truck already as the previous owner did everything half-assed to get it on the racetrack. The block is out of a 2000 Tahoe z71. Also, there is an MSD ignition and distributor, an optima blue top battery, and a push button start (key has to be turned right before you would normally turn it to crank it).

The problem-
I replaced the spark plug wires because a couple had melted because they were resting on the headers. I changed them out with Bosch wires (lifetime warranty) and routed them out of the way of the headers. Started it up and drove to the hardware store. Came out, tried to start the truck up. It turned over once or twice, and then quit. After a few more failed attempts, I assumed the battery died. I tried to get a jump- same symptoms. Let it charge from the other truck for 15 minutes- same. I left it there, came back the next day, and assumed it was a positive wire that was hanging down under the truck, right next to the starter. I tried to crank it over with that wire on every single post coming off the starter- same symptoms. My buddy moved the wire away from the frame and starter... I tried it a few more times and finally it fired up. We electrical taped the exposed wire and made sure it wasn't touching anything. Brought it to the gas station, put some gas in it, tried to fire it up, same symptoms as before. I kept trying to start it and finally some smoke came out from the positive battery terminal. I said enough is enough, my buddy and I were both confused and he tow-strapped me home. Here she sits. I have no idea what can be wrong. I am about to rewire the entire truck. I recently cleaned the battery terminals and added 4 guage wires from the pos battery to alt, negative battery to frame, and frame to engine block to ensure it was getting enough current. Here's something else that blows my mind- When I removed the stock positive going from the alternator, and tried to start it with just the positive 4 guage to the battery, the truck acted like the battery was completely disconnected. I thought the alternator wire simply went from the pos to to the alt?

Sorry for the long post, but I am trying to describe everything I can. The truck has almost no stock sensors hooked up. The voltage meter, speedometer, fuel, and temp guage are the only guages left stock because it has a carb. No map sensor, no o2 sensor, nothing really. Aftermarket oil pressure and tachometer are installed. Any help would be greatly appreciated!


06-25-2013, 10:11 PM
Reconnect the stock positive wire. It's not wise to remove any of the stock wiring, simply adding to it will accomplish your goal.

Probably need to figure out what your 'hanging wire' is connected to, I would start there.

06-25-2013, 10:21 PM
The stock wire is still connected. If I disconnected it, the electronics stopped working altogether. I will see where that wire is coming from tomorrow after work. Thanks.

Rich B
06-25-2013, 10:57 PM
Take the starter out and get it tested at an auto parts store (its usually free).

Sometimes starters will go bad and draw excessive current when you try to start the vehicle.

06-25-2013, 11:01 PM
^I'll add that to my "to do list" for tomorrow. Thanks.

06-25-2013, 11:08 PM
If your gonna have the alternator tested I would also have the battery tested as well. With a smoking terminal, battery may be gone as well.

06-25-2013, 11:11 PM
Semper Fi where are you deployed atm? I just got back from Afghan in April

06-25-2013, 11:12 PM
If your gonna have the alternator tested I would also have the battery tested as well. With a smoking terminal, battery may be gone as well.

^Got a point there. Probably the easiest thing to do anyway! Will do.

06-25-2013, 11:13 PM
Semper Fi where are you deployed atm? I just got back from Afghan in April

^^I'm in Camp Lejeune, NC. EAS in September. Hit me up PM if you wanna chat because I don't want to clog up this thread. ;)

06-25-2013, 11:25 PM
Does it jus crank and not turn over or nothin at all?

06-26-2013, 07:56 AM
It tries to crank about two repetitions and then the lights, stereo, cluster panel shuts off. The truck totally dies after a couple slow rotations.

06-26-2013, 01:45 PM
does this vehicle have the VATS system? i know gm started using it in 1988 but im not sure if it came on the trucks of that era.

06-26-2013, 03:42 PM

06-26-2013, 08:53 PM
Starter and Alternator both passed. Battery was pretty close to dead... He said I could come back in an hour and the test would be complete, but I just told him I'll come back tomorrow after work. I worked the loose wire up toward the engine bay, and took a pic. It has purple sheathing. The sensor has blue sheathing. I included a picture.

http://img594.imageshack.us/img594/7168/8ber.jpg (http://imageshack.us/photo/my-images/594/8ber.jpg/)

06-27-2013, 09:46 PM

She fired right up! The problem was the main wire going from the alternator to the battery. It was corroded most of the way through, creating a TON of resistance. I replaced it with a new, 2awg automotive grade wire. Thank you all for your help!

What I learned: If a wire is corroded in to the sheathing at all, replace it. The simplest answer may be the right answer. The sensor I was holding is the knock sensor, which I do not have. With a push button start and MSD ignition, the stock wire to activate the starter is not necessary. I learned that removing the starter is MUCH easier than holding the heavy bastard in place and trying to get the bolts to catch, especially if you are crawling under the truck without lifting it off the ground.

06-27-2013, 09:55 PM
Glad everything worked out...