Mobitronics Rectifier going strange

There's nice helpful ways to put stuff and rude condescending ways to put stuff so thanks for nothing ed.

Apologies, porl, if I sounded rude or condescending, as such was not my intention. Had it been, my post would have read something like this:

"Why would it spark when mulimeter prongs are put inside ? very carefully too I might add, no joinging of the +ve and -ve components."
You obviously lack even the basic knowledge to fault-find a DC circuit, so why tackle electronics? Your willingness to risk electrocution through ignorance is a great example of how "a little bit of knowledge can be a dangerous thing". And, albeit impressive in a homer simpsonesque manner, it doesn't alleviate the fact that others may read such drivel and feel that opening an enclosure and inserting probes (even if you are "very carefully too I might add, no joinging of the +ve and -ve components." , whatever that means ?) is safe.

But that wasn't what i was getting at.
ELECTRICITY IS INVISIBLE AND VERY DANGEROUS.
With the advent of cheap multimeters and the dispersal of knowledge via the internet the likelihood of accidental electrocution has gone through the roof.
I see many posts here (and on other 4WD fora), often by traders with little understanding of the subject that they're supposedly experts on, that are so wrong it's not funny (amps/hr is my latest favourite).
And this is what led to my comment.
As to being constructive, it's a bit hard to know where to start with this information (again): "Why would it spark when mulimeter prongs are put inside ? very carefully too I might add, no joinging of the +ve and -ve components."
I could try to explain that you're adding a high impedance (depending on the meter) either in parallel or series, both of which will have vastly different effects on a circuit . One being a factor of the sum impedence, the other a sum of reciprocals. And that's electrics. Start doing these things to an electronic circuit and it gets more complicated (actually it already was, but I'm trying to keep things simple).
Back to the "a little bit of knowledge" thing.
Without the proper schooling, it's very hard to see the danger in such work.
"Hell, I can touch both terminals of a car battery, so how can working on a car hurt me?" etc, etc.
Ohm's law gets bandied around too. And it is a cornerstone of electrical theory, but there are time when it doesn't apply (try using it to work out the "resistence" of a new battery, then check it with your meter). This will intrigue you both.
And I can't see how taking any measurement at pts in an electronic cicuit could be of help to someone who doesn't understand the ciruit logic. Without that how to know what/where to measure anyway. opr know where was a dangerous (read stupid) pt to place the probes.

I wouldn't have replied to this thread if I only wanted to stir things up. But I see things posted almost daily by people with little if any knowledge on this subject propounding their theories as fact.
And there are a few other forumites that feel the same way (from reading their replies).
Personally, i can't bake for anything. So I don't advise others how to make a cake.
cheers

ed

ok Ed, all good, I'm not that sort of stupid.

I can understand from your background now that my lack information led you to our misunderstanding. By "put the prongs inside" I did not dismantle the rectifier unit, I simply put the positive prong onto the positive terminal and the negative onto the negative terminal of the socket to measure if it was putting out 13.4v as the first step of seeing if in fact the rectifier was working or the compressor was buggered.

But from the above comments I'm happy to buy a new unit, it is five years old, and it will be a lot cheaper than a new fridge. Might try a different brand now though. Evakool have some units out, mind you there's not much choice on the market for 240AC to 12DC adaptors that are rated to 6 amps or above continuous. Not that I need 6 amps continuous but that's seems to be the range of what is available.