coreseller

Hey guys......I got a voice mail this morning from a buddy who has a 1988 911 that he tried to fire up (almost literally) yesterday. It had a dead battery and he hooked it up to a charger, he said it was set to 220 and as soon as he did something "popped" and smoke came out from underneath the passenger side of the dash, he also mentioned a "silver box" located down there. After the "pop" he did not try anything else to get it started.

Beyond that I do not have any further details, sorry for the vagueness and lack of info but I figured you guys may have some idea on where to possibly start, Thanks......Mark.

relinuca

In "theory", for whatever that's worth, the battery charger input (220v) and output (DC amperage) are isolated from one another by design, more or less.

But obviously, something bad happened here. Time for engaging an experienced tech.

relinuca

coreseller

My buddy just said the charger was set on 225 amp fast start

theiceman

Wow .. that sounds like its gonna need some work ..

Not sure whats under there on a Carrera but theres not much un der there on an SC so i cant help much.

Sounds like he was being impatient . Just for others viewing this NEVER do this on a dead battery , only in cases of emergency. He should have disconncted one side of the battery .. charged it fully , and then hooked it back up.

Even if it had started he would be putting 100% load on his alternator to try and recharge the battery, which is ill advised.

Sounds like he needs to have it towed to a compenant eectrical shop or get his multimeter out and get with the schematics.

Whatever fried I am sure is not protected by the fuse panel.

redridge

I would just cough up the 100 bucks and get a new battery...

Hopefully, that silver box is just an amp that is directly wired to the battery...

wwest

A completely DEAD lead-acid battery will not accept a charge immediately, might take a day or so even. In which case since the battery could not, would not, limit the charging voltage level then the charging voltage (220 AMPS, REALLY??!!) might have gone as high as 20 volts.

Under the passenger side dash...kickpad?
CB radio, cell phone, stereo amp,.... mouse nest near the blower motor nichrome wire blower speed resistors?

Just who would have access to a 220 amp charger and not know when to NOT use it in that mode?

coreseller

It turns out he had his wife's uncle do some wiring on the car, he did some looking around and there was a direct run from the aftermarket radio to the positive terminal on the battery, wow.

Thanks for the prior replies but I think I'm going to let him figure out the rest, no sense in trying to trouble shoot what sounds like may be a wiring birds nest.

Amber Gramps

Sorry, but man who does this stuff???

Most likely he connected the jumpers backwards.

theiceman

Even direct hard lines to the battery should be fused..... He's lucky he didn't lose his whole car.

GRINBOB

The only thing I know that is located toward the passenger side under the dash is the "computer" for the auto speed control. It is a silver rectangle box with a connector on one end. You can disconnect it w/o any problem starting or running the car.