Question about 1991 Jaguar XJ6

2 Answers

Mixed up jumper cables and fried car battery

I deserve the idiot award. I was in a hurry and accidentally attached the wrong jumper cables (positive to negative, negative to positive) when trying to jump start my car (was using a portable jumper system). It sparked and smoked and I realize I screwed up. I took them off and waited a minute and then put them on the right way. The car tried to start up but didn't turn over. And then it just went completely dead. After a quick search online I am kicking myself as it seems I might have fried my whole electrical system. If I am lucky it is only a fried battery and some fried fuses. My question is, in this scenario what things should a person check after pulling a ******** move like this? And what can they do to assess how bad the damage is? Fuses? Alternator? ECU? I think the answer might help out others in the future too. I am going out to get another battery tonight and see if it will start or at least the dashboard lights come on.

Posted by on

  • toritaiyo Apr 26, 2009

    Thanks 240cpa

    I took the battery to the auto parts store. It was toast but I got a new battery and put it in and the car started. So far it looks like the rest of the car is ok. I still have to look at all the fuses though.

    I was really worried that I might have ruined the alternator because I read on one website that crossing the cables might do that. But I found advice on how to check that ( You let the car run for a little while and then disconnect the leads from the battery. If the car keeps running while disconnected from the battery then the alternator is ok. Mine was, and I feel very lucky!

    I am going to check all the wires for deformations now. Thanks again for all of your help!



2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 548 Answers

Don't feel too bad, we've all done this or something similar a time or two. I did this once on another car and no major damage was caused. First, check the fuses to see if anything is out of order. I would take the old battery to have it tested at a parts store, as it may still be good. If it can be charged, charge it off the car and then try again to start the car. If that doesn't work, I would find a loaner or used battery to see if you can get the car started and then have the electrical system tested. If you check your owners manual or get a repair manual for the car, it should tell you where the main fuse block is and what to check.
Check for any melted or deformed wires at the battery cable ends and within the positive and negative wires' harnesses, at least as far down as you can see into the harnesses.

Good luck

Posted on Apr 22, 2009

  • Level 1:

    An expert who has achieved level 1.

    New Friend:

    An expert that has 1 follower.

  • Contributor
  • 1 Answer

Ok.. how about same situation... only new battery and car will only turn over.. and sat month and half in cold Ohio weather... any ideas?

Posted on Jan 30, 2014

  • Stallard David
    Stallard David Jan 30, 2014

    ok.. how about same situation... only new battery and car will only turn over.. and sat month and half in cold Ohio weather... any ideas?

  • Stallard David
    Stallard David Jan 30, 2014

    and mine is a Passat 2003



1 Suggested Answer



Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add


1991 Jaguar XJ6 Logo

1,558 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jaguar Experts

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers


Level 3 Expert

85223 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Are you a Jaguar Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides