Battery or alternator

[IntriguedUser]

Background:

I will start by saying that the earth ground from battery to car body is hanging by two threads. Cannot get it off as the bolt is rounded off due to rust. Car is immobile.

Car started dying electrically all of sudden, radio switched off, headlights going dim and on/off, headlights flickering like police lights, no power, misfire, car idled for 5 mins but died.

Now, I have used a jump lead to act as an earth and the car did not start, could not get it started even with jump leads and another vehicle. My feeling is the battery is now toast, I do not want to put a new battery on until the earth is fixed, unless its ok to just drive to garage to get earth fixed. Garage is a 2 minute drive away.

Do we reckon a new earth and battery will do it, or has my alternator died/died during the process of battery dying?

[rwilson]

Grind off the bolt and replace earth. Charge the battery. Start car and check voltage across the terminals with a multimeter, if the voltage is around 14v the alternator should be ok

Most likely the earth is causing the issues and that's a cheap fix which needs doing anyway

[GreenV8S]

Agreed - a volt meter would tell you whether the problem is caused by a flat battery, poor earth or something else.

[bigmadjohn]

99% sure it will probably be the earth strap causing your issues. In my younger days I had a Renault 5 Turbo and intermittently it just wouldn't start. After hours of tinkering, removing aftermarket alarms and even taking it to an auto electrician, I knocked the engine earth under the bonnet and noticed how much it moved, inside the crimp there was more copper corrosion than copper!! Swapped the cable out and all was good (with it starting anyway, was still an unreliable POS besides). To check the jumper cable earth substitute measure on an engine earth and body earth away from the cable with a multimeter-it should be 0 ohms with a cable that size. Eventually you will have to sort out the earthing cable, so I would do that first and it might cure your issue.