random running engine cut-out

April 1994 golf1 cabrio
Good and standard condition, all wiring is standard
Last spring had water ingress LHS (fuse box side) due to leaves in engine-bay blocking drainage holes

For the last 2months have a new problem: random engine cut-out ie engine stops running 

• can happen on motorway; engine briefly cuts out for less than 1 second then continues (all ignition display lights briefly go out)
• can happen while in town; engine cuts out then have to restart with ignition key (all ignition display lights go out until engine is restarted)
• frequency on a journey of 100km can happen between 1 to 2 times at most or even not at all ie random

Am not able to find a way to reproduce the effect (eg wiggle ignition key).
I have had a quick check in  the fuse box and there is no corrosion to any of the relay connectors

My golf1 garage is also not too sure what is wrong, though he suggests it could be the starter-key mechanism

Any ideas of how i could isolate the problem before work starts as i believe it is an expensive/difficult job to replace the ignition switch

Otherwise car runs well and is great fun!

I would agree with the garage, it sounds like the ignition switch is going faulty. to test for this on the back of the ignition switch jump the red wire to the black, this will bypass the ignition switch. if your car no longer cuts out when you do this then replace the switch.

The dash lights are fed straight from the ignition switch as well so the fact they go out when it dies pretty much confirms its the switch rather than the wiring or fusebox anyway.

to replace it you can do it with the ignition lock still on the car, using a small screwdriver bent so it will reach the screw holding the switch in place. the alternative is to remove the spline adaptor with a good set of gear pullers, then the ignition housing comes right off. any decent garage will be able to do this in under an hour if you really dont fancy it!

Many thanks for the fast reply!

What is the best way to get to the back of the ignition switch, in order to jump the 2 wires?

just take the lower column trim off, 2 screws

already tried that but there is so little room to work, will try again

I have managed to the plug at the back of the igintion switch and jump the two wires: red and balck

it seems to have cleared the problem, many thanks!


Though now I am trying to locate the screw to that holds the switch in place:

>>>to replace it you can do it with the ignition lock still on the car, using a small screwdriver bent so it will reach the screw holding the switch in place. <<<

can u please help

its jammed right in between the column and switch, very tight to get a tool in here so this is why getting a thin screwdriver and bending the end can help

Had a new part fitted in the garage, all runs well now!