End of a long day moving house, I had taken the battery out of my 72 ute to move my splitty project. Replacing it in the dark I got the cables the wrong way around, 10 seconds after hooking it up the clouds a
Of acrid smoke pouring from the engine bay alerted me to my mistake. After 15 mins on fire watch I hooked it up correctly and the red G light on the dash came straight on without the key even in the ignition. I disconnected it straight away. Could you please give me some advice on
A what will be definitely buggered.
B what is probably buggered.
C what could be buggered.
This will help me check through everything and get my much needed ute running again.
P.S. There was no smoke in the cabin.

It is a 1600 with a generator? I'd Change the regulator first, it will be fried, the generator may still be ok, you can test it by taking off the belt and motoring it with jumper leads hooked straight to the battery, neg lead to the body of the generator, positive to D+, spin it clockwise by hand and it should motor.

If you have an alternator, diodes will be fried, rest should be ok.

It will run ok with the G light on, it just won't charge the battery.

I'm surprised to hear of the smoke/damage without actually turning the ignition on of running it (not that I've ever done it ). But it obviously had some sort of hernia. to add to Dave's comments, I'm thinking the ign being on must have had some cables that have melted together and that was the smoke. There has to be some wiring that carried the direct short when the incorrect was made. Search where the smoke was and hunt out that melted insulation. Basically I'm thinking the wiring has melted a red wire (pwr all the time) to a black wire (coil/ign on).

I would be checking the wiring loom

as it will have heated up and most possible melted the insulation causing the smoke

Thanks guys. I'm running a 2 litre with alternator and electric fuel pump. I'm guessing rollover switch and starter relay as well.

I did the same with a type 3 wagon once. It ran fine. I couldnt understand why the clock wouldnt keep time. Apart from that there wasnt any noticeable difference except a reluctance to crank over likely because the battery wasnt charging lol. Spent money on fixing the clock.

Crap happens. We arent all experts. Bet you dont do it again.

Have a friend who recently purchased a Beetle - older resto but still a really nice car, registered, running fine and used as almos a daily driver for few weeks... only glitch was the fuel gauge wasn't working.

In process of hunting down why the fuel gauge wasn't working with a multimeter, another friend got -12V when he expected +12V... looked at the battery and yup - red to black and black to red on the terminals.

Switched 'em around and all good - including the fuel gauge now working.

Guess sometimes you can be lucky or unlucky with these things !!!

Won't do it again that's for sure. Might even shorten the leads so they can only reach the right terminal. The leads at the moment are about 2 feet long.