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markj1125, Auto Mechanic
Category: Car
Satisfied Customers: 4
Experience:  Licensed diagnostic and repair technician
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I jump started my R35 on wrong polarity and it is showing no

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Hi. I jump started my R35 on wrong polarity and it is showing no key on dash. Keys are connecting to vehicle when I press lock, with a beep, but pressing unlock to mobilise the car does not work. Any idea where the damage could be. Thanks in advance.
JA: Is this your first time dealing with this issue?
Customer: Yeh, it’s been in storage for 3 yrs and needs a new battery. I’ve jumped it many times but never on crossed polarity.
JA: What is the model/year of your Nissan?
Customer: 2009 R35 UK model.
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: charged the battery to full and disconnected the ground to see if it would reset. No joy.
JA: Anything else you want the Mechanic to know before I connect you?
Customer: nope all good except this issue. Owned the car for 9 faultless years and 32k trouble free miles. It’s just stupidity that caused this.
Hi I’m Mark I’m a Master Technician and hopefully I can help you with your issue today, first off you need to check every fuse on the car in all fuse boxes, there’s a high probability that you’ve blown a fuse, I would advise checking voltage both sides of the fuses if all fuses are ok then there is a possibility that a control module has been damaged in the process of reverse polarity, but checking every fuse would clarify this
markj1125 and 2 other Car Specialists are ready to help you
Customer: replied 1 year ago.
Thanks for the response Mark. I have not checked the fuses cos I’m an electrical engineer to trade which might be a bad thing in this case, so assumed that cross polarity would not hit a fuse till the current was on its way out, unless there was a reverse polarity protection fuse or device on the ground side. Have you come across this issue before?