Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Donor cables hooked up correctly, while the receiving car cables were reversed. It didn't start, but smoked instead. Mechanic shop used a portable jumper, then used receiving car again and had cables reversed. Again it smoked and didn't start. Then a friend checked and said alternator fuse had blown. They replaced it with a 75A instead off 100A fuse with instructions to replace right away back to the normal amperage fuse. They checked the battery and alternator with machine and they checked out ok. I took the car to a shop and replaced alternator fuse and radio fuse. They said the battery was shorted and alternator was no good. Is this possible with regard to battery and alternator?

share|improve this question

closed as unclear what you're asking by Zaid, vini_i, Pᴀᴜʟsᴛᴇʀ2, Move More Comments Link To Top Dec 18 '15 at 4:35

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question.If this question can be reworded to fit the rules in the help center, please edit the question.

4  
I have read and re- read this question but can't figure out what you are asking. Can you edit to clarify what the question is? – Rory Alsop Oct 28 '12 at 0:44
    
Please ask a real question that we can understand! – hillsons Nov 3 '12 at 14:35

It's entirely possible to burn out the alternator and battery by hooking the jumper box (or jumper cables) up backwards. The alternator can fry rather quickly (diodes will fry and the alternator becomes useless). The battery can take longer.

Basically when you hook a battery up in series (backwards) instead of parallel (normal), you create a circuit. This will not only create sparks, it generates a lot of heat which you'll figure out very quickly through the jumper cables. Putting them on backwards can fry the battery if left there long enough.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.