Scary Moment

[harrylime]

I discovered that the negative Battery terminal on my 12 month old Battery (from Lexus) would not tighten as the terminal post was too small a diameter for the negative clamp. In trying to find a solution, there is a plastic fitting on the negative clamp that looks as if it's intended to insulate the base of the clap from the Battery, with a plastic lug that looks as if it's intended to insulate one side of the clamp from the other(the bolt goes through one side of the clamp, then through the plastic lug, then through the other side of the clamp). This lug was acting as a washer and preventing the clamp being tightened as much as it could.

I removed the plastic fitting and then put my voltmeter across the terminals before trying to start the car. There was a loud pop and a flash and my voltmeter cables got very hot. It got me wondering whether the plastic lug fulfilled a function, even though logic told me that it's the negative terminal so could not be shorting anywhere.

I was then anxious about starting the car so rang my local friendly mechanic who agreed that it should be fine. I eventually started the car, having run out a hose pipe as a precaution and it started OK . Next time I tried it, it turned over fine but would not start. This is a first for this car. I left it for five minutes and it then started. I took it for a run and it seems fine. I can only think that all the buggering about confused the engine management system , so it went on temporary strike

My meter was put on with the right polarity and was on the 20 volt setting. I assume the meter was faulty, although it seemed OK last week, so I've binned it

[ColinBarber]

are you sure you had the leads in the voltage sockets on the meter and not current?

[harrylime]

Bingo Mr Barber. You win a coconut. I was checking amperage last time I used it (the first time I've used that function) and forgot. The red lead was in the wrong place. Thank you very much, It's great to know what I did wrong. New voltmeter needed now I imagine

[ColinBarber]

The current circuit of the meter should have been fused so you would need to replace that blown fuse. The voltage part of the meter may still work.

[harrylime]

I have tried it and the voltage side does still work. Felt like such an idiot, schoolboy error

[steve2006]

Don't worry,I've seen worse this week with incorrect wiring connections :)

[ColinBarber]

didn't they do well :o

[harrylime]

yep, ex fireman, seen that a few times