Battery fry causing gear-shifting issues with Chevy van

van
chevrolet

#1

I travel and often live in a 94 chevy g20 3/4 ton van. Today I started it up and the electrical was flipping out, I got to the end of the road and I smelled electrical smoke and the van died. I opened up the hood and the piece of wood that I usually wedge between the battery terminals and the metal frame of the van (the battery is very poorly placed and slides around) had slid out of place and the positive terminal had melted a bit and fused to the frame.

After I got it unstuck, I got a jump and it started right back up fine, but now when I turn on anything electrical my gauges drop slightly for a moment and my gear wont shift from low gear (it’s an automatic transmission). This definitely won’t do, but I am extremely poor and unstable right now as I’ve moved away from family to start a new life and I’m trying t get work and I’m running on fumes (heh) financially so I thought it might be a good idea to try talk to some people about it first… Any ideas?


#2

I think the TCM may be damaged. This van should have a transmission that is computer controlled. The electrical problem may have damaged the control module. A reset may help. Disconnect the battery for an hour or so and see of it helps.


#3

The battery should be strapped down. I suggest you go to a salvage yard and purchase the parts you need to do that. It shouldn’t cost you much for those parts.

You might have blown the fuse that connects the alternator to the battery due to the short you had. You may have also damaged the alternator. I suggest you have a load test done on it. Places like AutoZone may do that for free. Check all the fuses and fusible links for any problem with them even though the short was before them.


#4

The battery and alternator are now toast…can you imagine the current draw…several thousand amps on a dead short to a car battery. This high current will ruin a battery. Maybe the alt is ok if engine stopped but if the alt was still turning you may have blown the diodes. I would put a new battery in then check the voltage with the engine running, should be about 14 volts give or take 10 %.


#5

I took the battery into NAPA and they said it was fine… Checked fuses and those look fine… when the battery fried, the engine did shut down so I think the alternator may be alright. I’m about to haul this beast slowly to go get tested.


#6

You probably fried the PCM. The PCM controls the 1-2 and the 2-3 shift solenoids, and the 3-2 control solenoid in the transmission.

You won’t find any blown fuses because these are on located on the positive side of the circuits. When the positive battery terminal grounded out on the frame, you sent current thru the grounded side of the circuits where there are no fuses. So this current snuck in thru back door of all these circuits.

And you can’t send several thousand amps thru the elecrical system. At most, the electrical circuits were exposed to the cold cranking amp rating of the battery.

Tester


#7

You can send several thousand amps when you dead short a car battery…The CCA says how many amps the battery can supply without voltage dropping below a certain voltage for a number of seconds. I have been an EE for 40 years…I have seen rechargable Nicad batteries that were only rated at 500 MAH ( 1/2 an amp hour ) take out a piece of 22 gauge wire, which would take 15 amps+ to burn when hit with a dead short. The battery will deliver as much current as the internal resistance of the battery !


#8

I think you probably have damaged the battery and maybe the charging system, you may have damaged an alternator diode. Why not try this idea as you are cash-strapped. Take your van to one of the many retail auto parts stores that will test both the charging system and battery for free. They do this b/c they can sell batteries by providing this service. But there is no requirement to buy a battery. My local Sears Auto has done this for me before, and are always more than happy to do it. If I’m only concerned about the battery, I’ll remove it first, then they can test it inside the store. The less monkeying around inside the engine compartment the better I think.