Battery Terminal Disconnected- Car Won't Start

I used my car to jump start someone else’s car. The jump worked and my car was fully functional prior to the jump. My car was still on when I disconnected the jumper cables(first mistake). When I disconnected the negative jumper I didn’t open it enough and the negative terminal came off the battery with it. The car died. Now it cranks, but will not start. I’ve checked all fuses. They are fine.

You need to get it checked out at a shop. One of the functions of a battery is to absorb electrical spikes. When you disconnect a battery while the engine is running (in your case the negative terminal broke off), those spikes can cause damage to electrical components since the battery is no longer in the system to absorb them. Just disconnecting the negative battery cable should not cause your engine to quit running. It will run without it connected. So, some damage was caused when the battery was removed from the system.

Dang… Is it worth paying for a tow and a diagnosis for something that might end up being really expensive? Or do most people just scrap it :frowning:

There’s only one way to find out. Get it towed and diagnosed. “Expensive” is relative based on your budget and the value of the car.

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What is the year, make, model and engine of the vehicle??

2003 Jaguar S Type R. I’ve also made a short video demonstrating the problem.

You checked all 3 fuse box fuses?? I mean ALL the fuses…

I am very unfamiliar with a Jaguar, but couple things:

-Your tachometer is not moving when starting your car (as are none of the other gauges.) I think it should be. This makes me wonder if you didn’t blow some sort of fusible link wire and the ECM is not completely powered up.
If you checked all the fuses, this could be a possibility.

-I briefly saw a red wire near the positive battery cable. It doesn’t look like a factory wire, but what does it go to? Should it be hooked up?

-Did you verify both battery cables are now tight?

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With the ignition off, disconnect the battery for five minutes. Reconnect the battery and unlock the doors using the remote (this deactivates the theft alarm), then start the engine.

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For future reference, get a lithium battery jump starter. They’re relatively cheap and they work well as far as I know. That’ll protect your car from any issues like this.

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I disconnected the battery and left it then unlocked the car with the fob and tried starting it. It cranks, but no dice. I double checked the fuses in all three boxes(hood, trunk, glovebox) and did not see any blown fuses. For the most part the electricals seem fine. I can put it in accessory mode and use the windows and radio. The dome light and headlight come on as they normally do. Just no ignition. That extra dangling red chord in the trunk by the battery has always been there and never connected. There’s a multidisc changer in the glove box and I think that’s what the red chord was for, again never used it.

I haven’t tried jumping it. I used my car to jump someone else’s so I have to wait for them to get back before I’ll have another car for jumping. I figured since it hadn’t had a problem starting before I shouldn’t need to jump it. I did test the battery with a multimeter… 12.56v

“fusible link wire”… What is that and how do I check it?

For cranks but won’t start usually the problem is either no spark or no fuel. The first step towards a solution. is to determine which. Ask your shop to either check for a robust visible spark at a spark plug during cranking, or if the engine configuration makes that difficult, spray a dose of starter fluid into the air intake. If it then starts and runs briefly, the spark is ok, and the problem is no fuel.

this may or may not be your issue. Many times these go to the alternator, which is not your issue. No need to try to jump this car, as it turns over well. as George said, your issue is likely fuel or spark. Judging by your dash, something electrical has turned off fuel or spark.

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You said you checked all the fuses, and they are good. I think you should check your relays too.

How to Test a 3, 4 or 5 Pin Relay - With or Without a Diagram - YouTube

also, Nevada might be on the right track with your alarm system. check your owner’s manual to see if there is a specific way to reset it for your vehicle.

See if your Jaguar has a fuel pump inertia switch in the driver’s foot well side panel.

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Thanks all for the responses. I will do some homework and try some of these ideas and report back in the coming days.

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You can pull the battery terminal off with the lithium jump starter too!

First thing is to connect a scan tool and see if the ECU is working. The ECU might be blown out by a Voltage spike. If it has a security system, the ECU could have lost contact with the security module and it won’t let the car start.

I got a scanner and this is what it tells me. I don’t know what any of it means. Anything of concern?

Here are the error codes as well.