Jump start warning!

[Mike405]

When my car was with the independent garage they were trying in vain to bring to life a recent F Type convertible.

The owner had been away for 3 weeks and on his return the battery was flat. The AA were called and jump started it. The mechanic fitted a new battery and left. There was no power when the owner tried to start it again. Allegedly the AA refused to recover the car to the garage, incurring a charge of £400 for a suitable recovery vehicle.

You will probably know that there are specific instructions in the handbook regarding this operation. The suspicion is that either the jump start fried something, or the mechanic, who fitted a second battery when the first didn’t work, had a battery with the posts in the opposite position to the required one, fitted the second battery and departed quickly having realised what he had done.

The problem for the mechanics was that they were unable to get any power in the vehicle, whatever they tried. Without the ignition switch having power they couldn’t use an OBD reader, couldn’t move the seats to gain access where needed, couldn’t close the windows, had to sheet overnight etc. They were going to get some industrial grade dollies to,put under each wheel to move it inside.

While I was there they were engaged in a long conversation with Jaguar technicians but they were stumped as well. Clearly a ‘computer element’ somewhere has fried but where?

So the moral of this post is make sure that if your car is jump started don’t just accept what the mechanic involved is going to do, make sure the correct procedure is followed!!!

[Kev]

Trouble is with these new-fangled motor cars and their electrical wizardry is the easy chance of frying something if you’re unfamiliar with the relevant procedures. In defence of the AA* technician, they can’t be expected to know everything about all cars and all it takes is a momentary lapse and it’s game over for something expensive. Most of us will be familiar with the procedure for an F-Type but what about an S-Class or i30N? A lot of drivers wouldn’t even be aware of how to jump their car (apart from that chap and the Austin Princess from many years ago)

On the flip side, you’d expect a professional breakdown organisation to have that sort of information available to the technician via the job card or other method as an aide-memoire when the job is sent to them given the it was a non-starter?

I can’t understand how the battery could be fitted the wrong way as one clamp is slightly smaller than the other, plus the cables wouldn’t reach, or it was a completely different battery?

There are many modules which can be cooked quite easily, and if one has gone down taking the CANBUS with it then it’s a whole world of pain trying to find which one

*Other breakdown services are available

[scm]

So long as the battery is in good condition and charged when you leave it, it should easily do 3 weeks without going flat - MIne was left for three months when my neighbour was doing work on our shared drive and couldn't use my car (and isolating during lockdown didn't help!). I got a low battery warning when I eventually started it, but it started fine - I then put it on charge to get everything sorted. The only reason I can think of an excessive battery drain would be the dreaded "disconnect from the OBD port" without shutting the session down properly. That manifests itself by the light in the hazard switch never going out after locking the car (it should extinguish after about 10 minutes).

[Lunar]

Apart from that chap…

It seems to have been an 1100 Countryman.