Jim Grant's Tech Tips
‘95 Hyundai Sonata, Backwards Battery Installation
Q: A friend installed a battery backwards in my daughter’s ’95 Hyundai Sonata. But with a brand new battery the car does nothing. Emergency lights, dome light, and trunk indicator dash lights respond. Help? My husband is looking for electrical answers that are possible. Is there a “safety” mechanism on this vehicle?
- Deborah Samstag
A: This could be an easy fix or it could be the start of a nightmare. Under the hood of your Hyundai there is a fuse and relay box. Inside this box is a group of large fuses called fusible links. When a battery is connected backwards, electrical power travels backwards through the electrical circuits. If the circuit is a switched circuit, it is unlikely any damage will occur. Then there are the circuits that the electricity just plain runs wild in! This is where the most expensive damage can occur and this is where the luck can kick in too. The fusible links are circuit protectors, if too much electricity gets running through a circuit the fusible link puts a stop to it by burning out/failing, but it’s not failing, it’s just doing its job. Fusible links don’t know and really don’t care which way the electricity runs through them, as long as it is not too much. When the battery was installed backwards the electricity was let loose and was burning through the wires, alternator, computer and other fun stuff. A fusible link will not put up with such exploits and will end the fun by failing. When the fusible link fails, the flow of electricity is stopped in its tracks. Because of a failed fusible link the battery, even when installed correctly, will not provide power/electricity to the circuits. The fusible link has to be replaced first. Check out those fusible links, I’m confident you’ll find one or more have done their job. Once replaced, all you have to do is turn the key to see just how lucky you are.