By dallasnews Administrator. A co-worker needed a jump-start, and I thought I would be a good Samaritan and help her. I had to pull up next to her in the opposing traffic lane to be able to reach her battery. In my haste, I put the positive and negative clamps on the wrong terminals on my car hers were attached correctly. When I got in my car to start it, I could see that the wires were smoking. I immediately got out and disconnected the cables. We bought new cables, and then we were able to start her car.
If current flows backward through lights that's not a problem. Most of them are designed to withstand reverse polarity. Check the high ampere fuses on your car. This may be a 40, 60, ampere fuse and it is usually hard to find.
Oct 03, Well first of all if you hook up jumper cables backwards you will get a big spark off the battery. telling you it is something wrong. and you need to check your connections. For this not to happen look at your battery before hooking up the cables. There it a + for positive which is red and a - for negative which is black. Oct 26, In fact, if the radio is the only victim here, you would be a good Samaritan and a lucky one. RAY: Usually when someone crosses the terminals in a jump-start attempt, there's a lot more electrical-system damage. One of the cars even can burst into flames. That's usually our first hint that something's wrong. Dec 09, What happens if you hook up battery cables wrong; Accidentally installed car battery in reverse; Hooking up battery cables backward; Hooked battery up backward on four-wheeler; Connecting the jumper cables backward or installing a new battery the wrong way is never fun.
Here is a picture of this fuse on a Honda Civic. When the jumper cables were connected backward, this fuse blew. This is from a Honda Civic.
Notice the fuse strip. More than one fuses can blow. Once you replace this fuse, start up the car. In most cases, the car should start right up.
Installed new battery backward, the car won't start
If it doesn't, continue to Step 2. When you attach the wrong cables to the wrong nodes on a battery, it results in a very high current flow to the battery with a lower charge.
The fuses in your fuse box are designed to burn out and break in the event of high surge of current in order to spare your vehicles components from frying. Basically how a surge protected power strip works or how the old screw-in fuses that were common in houses until breakers become standard.
Most of the time the fuses do their job correctly. However, on very rare occasions a fuse will weld itself together, creating a constant connection between battery and component. This actually happened to my mother in law's truck a couple weeks ago.
Her vehicle wouldn't turn over, however all the lights were working so the battery still had a charge. We figured the next logical thing to check was the starter.
Oddly enough, when we replaced it, the truck started immediately after connecting the cables to the starter - the keys weren't even in the ignition. We swapped out the fuse for the starter in the fuse box and it turned over only when we cranked the keys in the ignition.
Check your fuses first, and if the Jeep still isn't turning over after replacing them, then start troubleshooting other damage from there. Easiest way to tell if an electrical component is damaged is with a charge tester.
Touch the positive and negative nodes to the corresponding connections in the component and it will tell you if they're still allowing current to flow through properly. You can get one at any hardware store, or swing by a mechanic or auto parts store and they will likely test out your component for free.
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Or you could just see if the Jeep will crank once you've replaced the battery and repaired anything that might have burned up :. If one connects a strong battery to a vehicle's electrical system with reversed polarity, nearly-unlimited current will flow through the alternator until it blows a fuse or fusible link, melts a wire or diode, or does something else catastrophic.
Reverse-connecting a strong battery to a nearly-depleted battery that was itself connected properly would do likewise, though the depleted battery would pass much of the current itself likely doing significant damage to itself in the process thus reducing the amount of current flowing elsewhere. Note that reverse-connecting two batteries of equal strength cause damage equivalent to short-circuiting one battery.
If the batteries are of unequal strength, the weaker battery will be damaged more severely from that experience than it would be from a short-circuit, though if the weaker battery properly tied to its vehicle's electrical system enough current might detour through the electrical system to reduce the damage sustained by the weaker battery.
It was an 07 Buick Lecrosse with the factory battery still. The battery was bad and was the only problem until the customer attempted to jump start it and hooked the cables up backwards. It ended up melting the headlight control module, the fuse box itself in the engine compartment, one connector, and a few wires in the main harness. The store should pay to restore your car to the condition is was in before they messed up the battery installation. The position of the old battery is not material, and is no excuse for the store hooking up the + cable to the - terminal of the battery. They owe you to make it right, it was their mistake. Connecting the jumper cables the wrong way might actually damage your vehicle. If your battery is running low (that's why you can't start) then you have less voltage across it's nodes. When you connect another battery with the exchanged nodes, the current will flow out of your battery (since it's voltage is lower) and damage the battery.
If a hired "professional" connects a charging apparatus with reversed polarity, I would suggest that the customer should be entitled to have his vehicle inspected for electrical damage by a mechanic of his choosing, with the hired professional being responsible for the actual cost of his inspection or a typical mechanic's cost, whichever is less, along with the cost of repairing any electrical faults that are discovered and for which the reverse connection would be the lost likely cause.
Note that such an inspection should not only try to figure out the causes behind observed problems, but even more importantly should look for damage which has no symptoms but could undermine safety. If a wire gets hot enough to destroy most of the insulation, such damage might have no immediate effect, but could lead to a later short circuit that might start a fire.
If a wire's insulation is compromised in a fashion that might affect safety, the "professional" should pay to have it replaced, without regard for whether it's causing any immediate trouble. I believe there are too many variables to say for sure. It would depend on how long everything was connected incorrectly, how much damage the fire did along with what circuits were involved.
Circuits that are not normally related to the starting or charging systems may have been damaged by the fire or by feeding power thru the ground side of the circuit.
Jumper cables are not designed to carry the huge surge of electrical current, and will quickly heat up to very high temperatures. This can melt the insulation on the cables and potentially expose people to direct contact with the electrical cables. The heat can also melt solder and other components that hold the cables and clamps together.
I would recommend you have the electrical system evaluated by either the dealer or a shop that specializes in automotive electrical systems. You may have damaged wiring that will be a problem later.
Then send the towing company the bill. If your battery is running low that's why you can't start then you have less voltage across it's nodes.
When you connect another battery with the exchanged nodes, the current will flow out of your battery since it's voltage is lower and damage the battery.
Assuming your battery is fully depleted after some time, what will be left is a battery only one left connected vice versa to your car. Not every component in your car can withstand this some parts - like radios have a protection circuitery.
What happens if u hook up jumper cables wrong
Fuses can only limit the currrent flow, but not it's direction. Sign up to join this community. The best answers are voted up and rise to the top.
Home Questions Tags Users Unanswered. Can hooking up jumper cables incorrectly damage the electrical system of the receiving vehicle? Ask Question. Asked 4 years, 9 months ago. Active 4 years, 9 months ago. Viewed 39k times. Sandi Sandi 71 1 1 gold badge 1 1 silver badge 2 2 bronze badges.