How bad did I screw up? (1 Viewer)

Joined
Jun 6, 2005
Messages
89
Location
Nairobi, Kenya
This morning I was trying to jump my wife's car- it seems the batteries (12Volt Surf with 2 batteries) were both dead and after 30 minutes of jumping and nothing I decided to swap my good battery into her car. To make a long story short, I screwed up and put my battery in and then connected the positive to the negative terminal and the negative line to the Positive terminal.

Did I kill my battery? Could I have damaged anything in her car? My battery is still starting my car fine, but the alternator and voltage regulator seemed like they were extra hot yesterday. Am I just imagining things, or did I screw up my battery and it's only a matter of time before it's dead? I haven't started her car yet as the two batteries are both flat completely.

John
 

Ron R

Drive a Landruiser, enjoy life
Joined
Dec 20, 2006
Messages
839
Location
The Netherlands
John,
did you try to start your wife's car when your battery was connected?
If not, I don't think you will have to worry about her car.
If so, there could be damage to electronic stuff. It depends.

What rig do you have ? 24V? or 12V
If 12volt there is not a lot to worry about. Your battery won't be damaged unless you had it connected for quite some time.

IF your rig IS 24 volts, then disconnect both batteries and charge both separately from each other. Then, when charged, connect them in parallel (+ to + and - to - ) and charge them that way ( at 12 V) for about an hour.
This way you equalize the one battery that got drained during the starting attempt.
 
Joined
Jul 22, 2003
Messages
18,213
Location
Perth Western Australia
Reminds me of an auction I went to last year. There were about 20 79 and 105 series coming up for sale.

At the beginning of the auction the auctioneer announces that LOT so and so has had a malfunction after the battery leads were connected the wrong way and the computer is now dead.
So when it went up for auction it went for about $3K less than the others.
Later on when I was thinking about it ,I could not recall the 105 series as having a computer like the 100 series and if the electrical system was dead it was probably a fuse link.

Ah, I was bidding on a dual cab 79 series anyway.
 

Ron R

Drive a Landruiser, enjoy life
Joined
Dec 20, 2006
Messages
839
Location
The Netherlands
Reminds me of an auction I went to last year. There were about 20 79 and 105 series coming up for sale.

At the beginning of the auction the auctioneer announces that LOT so and so has had a malfunction after the battery leads were connected the wrong way and the computer is now dead.
So when it went up for auction it went for about $3K less than the others.
Later on when I was thinking about it ,I could not recall the 105 series as having a computer like the 100 series and if the electrical system was dead it was probably a fuse link.

Ah, I was bidding on a dual cab 79 series anyway.

Well, startermotor, wipers, bulbs and that kind of stuff will hardly be damaged. But it's the electronics (Radio/CD-player, Nav equipment, (car-)computers, engine management-systems) that are prone to damage. And if you are talking about engine-management systems you talking big money.
That's why I love my 73. No computers, just some relays. KISS !!!
 
Joined
Mar 14, 2006
Messages
189
Location
Calgary, Alberta
Reverse polarity diode

I would be very surprised if any of the electronics have been damaged by causing reverse polarity.

Why? Most MODERN (!?!) automotive electronics are designed to cope with this for the reason that "$h!t happens." There is no defined date as to what is "modern."

How? A diode is put in series internally within the electronics. If the correct polarity is applied, the diode is forward biased, power is drawn with small voltage (0.7V) drop across the diode. If power is applied in reverse, the diode is reverse polarity, non-conducting and the electronic device is protected.

Funnily enough for some automotive electronics, there is usually more of an issue with power being applied without the intentional ground being hooked up via the wiring harness. Usually, the device will find a ground path through the case which may or may not be intentional.

If you can see or smell the magic smoke if you screw up, it's like the genie in a bottle, the magic is gone and the electronics don't work anymore... :)
 
Joined
Jul 22, 2003
Messages
18,213
Location
Perth Western Australia
Well, startermotor, wipers, bulbs and that kind of stuff will hardly be damaged. But it's the electronics (Radio/CD-player, Nav equipment, (car-)computers, engine management-systems) that are prone to damage. And if you are talking about engine-management systems you talking big money.
That's why I love my 73. No computers, just some relays. KISS !!!

I dont think the 105 has all of that,electrically speaking its the same as a 7* series of the same year, but it got sold for $9000 with 130000klm with a good body and interior and dual cab(2000 model)
 
Last edited:

Tapage

Club 4X4 Panamá
Joined
Apr 4, 2003
Messages
23,562
Location
Panamá
Dude .. don't worry for your bat or your wife car .. Old car ( and Toyota ) are not worried about those issues .. I thought your 4runner was 24V right .. in this case no more than paralel conection was made ..
 

Duane

IH8MUD Wookie
Joined
Nov 20, 2006
Messages
707
Location
Medicine Hat
I would think your battery is just fine as it is capable of supplying a far greater current than most things can handle in your wifes vehicle. I would be very surprised if you shortened it's life.

I would be more concerned about your wifes car/Surf. Don't know it's particulars but I assume there would be a fuse at worst that is gone. Look after getting your batteries recharged(trickle charge) to see if they will come back and then go from there.
 
Joined
Dec 14, 2005
Messages
1,512
Location
colorado
Saber tooth is right,

Alot of radios and especially avionics have a safty diode built into the voltage regulator area of the electronics. I cannot say this is the same for today Electronic control units but its purpous is to not pass voltage to the rest of the electronics circuits if the polarity of the voltage is reversed. The worse case you may have to do is replace the diode if its shot.
 
Joined
Jun 1, 2006
Messages
5,153
Location
Port Coquitlam
No problems, I have seen many dumb things in my line of work. Reverse polarity will not damage anything. The battery should be fine, now if you connected your positive lead to a grounded lead and shorted the battery then you would have cut down it's life span.
Those pesky red and black labels.
On a side note: If I am not mistaken Jaguars were for a long time running their vehicles entirely opposite. They used positive to ground and run the negatives back to the battery. Like planes.
Crazy British engineering:D
 
Joined
Jun 6, 2005
Messages
89
Location
Nairobi, Kenya
Well it seems that evrythign is fine- no problems with the electronics so far and all the batteries are holding a charge fine. Thanks for the help!
 

Users who are viewing this thread

Top Bottom