Thread: Full beam coming on when I put parking lights on. Intermittent issue.

A rather vexing head scratcher...

2008 Puma 110 Wagon. I normally drive with the parking lights on, i.e. the short stubby switch to the left of the steering wheel pushed forward to it's first position only, not the second position which is farther forward and activates the low beam headlights.

The other day I got in as normal in the morning and when I put the parking lights switch to position 1, the full beams came on, with the blue light on the dash indicating that they were on. I checked the indicator/ full beam stalk and the switch positions but all seemed to be ok and in the correct position. Turned them off and on again, same problem. Drove without lights, no issues, it was daytime.

Turned ignition off and on again - behaviour was as normal but then within 10 seconds the full beams came on all by themselves. I've driven the car a dozen times since then and 75% of trips the lights acted perfectly as normal, the other times full beam only, no parkers, no low beam, all or nothing baby!

Anyone got any ideas what I should look for first? I haven't taken the wheel off before or got into the switches behind it so I'd appreciate any advice. I need to drive in the dark tomorrow evening so having full beam only would be horrible and likely get me in trouble.

Cheers

UPDATE:

Couldn't replicate the problem at the workshop (KLR Windsor). Everything worked as it should. Bloody annoying.

Spotted some discolouration on the indicator/ full beam/ horn stalk wiring but it was still working ok. As a precaution and for testing purposes we replaced that stalk and kept the original light switch (the stubby one) as we couldn't replicate the problem.

I got home and the next day, got in the car, turned engine on, turned parking lights on as I always do, all good. Drove to the top of the drive and bam! All by itself the blue light came on at the dash and the full beams were activated and could not be turned off without turning the light switch to position 0 (off).

Using a test light, I checked the points on the light switch (while still in first position) and it is not faulty i.e. the light switch only sends power to the full beam stalk when in position 2 (headlights on), not position 1 (parkers only), so the full beam stalk is getting power from somewhere else. Also, I noticed that it does this whether the engine is running or not i.e. keys in my pocket, turn light switch to position 1 (parkers only) and full beam comes on....so it's getting power from a permanently live wire somewhere.

Does this suggest that there's a bad earth somewhere or that maybe some wires have rubbed through and are connecting somewhere in the wiring harness?
Car is due for rego inspection and a service but I'd love to get a sense of where to look first to see if I can save myself a few bucks on having professions hunt down the culprit.