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Electric shock from dizzy. Constant when running
Aussie Dubbin - May 18th, 2014 at 09:16 PM

Any ideas? My HT lead from coil to middle of dizzy is giving me a hell of a shock and I can't work out why? Could it be a bad lead or bad lead connection. It's not the leads that go to cylinders just the one.
It's not fun testing it each time too.

Thought maybe a bad earth? Earth for alternator goes back to battery and I piggy backed this to the fuel pump mount?

Cheers

barls - May 18th, 2014 at 09:50 PM

possibly old leads.
its not a good idea to touch them while its running as you have just found out.

vlad01 - May 18th, 2014 at 09:53 PM

Isn't that normal for a dizzy with kind of leads VW tend to have on them?

I got shocked every time just about with any car that has a dizzy and therefore I do not touch them when they run, not even if the engine not running and ignition on.:crazy: ouch!

the reason you get shocked is, you are being a shorter path to ground for the high voltage. Because the high voltage has to jump the rotor button gap plus the plug gap, resistance in the ignition leads, crappy boot on the center lead wont give enough resistance from it to your hand, so it is taking that path.

If you use copper core leads from dizzy to plugs, that should reduce the incidence of shocks, I would check the resistance of your leads, they might be stuffed and getting shocked easier as a result.:lol:

I remembered I was fixing a car for my uncles neighbour long time ago, its leads were stuffed and the sparks were jumping from the coil to the block which were about 60mm sparks !! leads read like 15K resistance, new ones were 1.5-3k it was safe to touch after that.

Aussie Dubbin - May 18th, 2014 at 10:18 PM

Cheers the leads aren't that old I will check brand tomorrow but in pretty good nick I thought. And I'll measure resistance too. Thanks fellas

ACE76 - May 18th, 2014 at 10:23 PM

You can get a shock from the outside of the lead, from induced voltage: no direct contact needed -- anything above 2 or 3000V could do this, depending on distance etc. If you are holding the centre lead to check for spark strength, hold it in the middle with insulated pliers.

vlad01 - May 18th, 2014 at 10:29 PM

2-3000v?

add another 0 there for conventional coil, double that again for DIS type coil packs.

mgiles - May 19th, 2014 at 10:26 AM

Quote:
Originally posted by ACE76
If you are holding the centre lead to check for spark strength, hold it in the middle with insulated pliers.


x2 - if checking for spark I use a pair of insultated needle nose vise grips lightly gripping the wire so it wont get damaged.

Cant say I have ever been zapped being in the vicinity of wires though.

AA003 - May 19th, 2014 at 07:39 PM

I always put my tongue on it to check for voltage.