Classic/Antique Car Repair: Mexican Beetle none start sometimes, mexican beetle, vw beetle

Question
Hi

Please help, I own a 1991 Mexican 1600cc VW Beetle, I have owned it for 2 years, the problem is occasionally I turn the key and nothing happens or turn the key and there is a slight delay on the engine turning over. I have had two new Batteries on, a new starter motor and bushes, a new regulator and a new key Barrel and the last thing I have done is installed a battery cut off switch as I was thinking something my be draining the battery. This has helped but it is still happening after the switch was installed.  When I turn the key and nothing happens I jump start the car with leads and it is fine.  

I have also noticed that whilst driving in the dark and I have the lights on and use the indicator the red battery light flashes alternatley with the green indicator light or use the brake the red battery light comes on.

Could this be a degraded wire somewhere?

Thank you
Rachel

Answer
In about 85% of the cars I have worked on with similar problems, it has turned out to be a bad ground cable or end. I would start there.

If all checks out, the bottom line is your are not returning enough voltage to battery, either through a fault in a cable or electrical output.