Flashing turn signal oddity

[Tyril]

Late last night I was cruising down the turnpike doing 80-90mph average. Every now and then I would notice a dull flash coming from my instument cluster. Driving at that speed, watching the road, and staring at cluster wasnt easy, but I managed. I finally discovered that the left turn signal indicator was flashing erratically. At first I thought it might just be catching some light off of someones headlights, but quickly ruled that out. I tried playing with the turn signal arm, thinking that maybe it shorting out. Nope, tried right and left signal, both worked fine. Now, when I say flashing, I mean strobe like, far from the normal "blinking" interval. Occasionally, it would also just stay on steady for up to 3 seconds at a time. I also noticed that when it was "flashing" I did not hear the normal relay clicking noise.

My girlfriend was driving behind me during all this, she said the actual left turn signal light was flashing erratically, so It was more than just the indicator light.

I can think of two explanations - A relay might be going bad, or....

This theory is a bit out there -

It seemed to act up more frequently when I was near / passing tractor trailers. I know a lot of truckers boost their cb radios to insane power, and also overmodulate. If any of you have ever used CB radios before, Im sure youve noticed that you can sometimes interfere with other electronics, ie, you can hear your voice on nearby TV's and stereos.

I wonder if somehow a wire was the same length as the wavelength (or a mutltiple of) they were transmitting at. I believe that it is possible that their conversations were causing a voltage to be induced in my car wiring, thus causing the relay to fire. I might have been experiencing a visual representation of their conversations.. hrmm


Or maybe it was just another VW electrical gremlin

 

[OilBurnerBob]

Sounds to me like you have a loose wire or bad relay putting a voltage on the tail light wire under vibration - that would explain why it was more 'active' passing trucks - wind buffeting the car.

 

[Kyanoti]

The turn signal indicator will turn on any time the turn signal itself turns on... likely, some errant wire is connecting to the actual turn signal, and your cluster is telling you that the light is on. Does it happen only when your headlights are on? I would take out the suspect rear tail light and make sure all the connections are clean and dry, and then inspect the harness. (To take out the tail light holder, access the rear of the fixture by taking out that hard cloth cover with the twisting clip on the appropriate side of the trunk, unplug the wire harness, and unlatch the two clips that hold it in--easy as shifting an automatic. It may take some wiggling to pull it out, though.) This happened to me when I doubled up my rear brake lights.

 

[Tyril]

I just noticed it last night for the first time. Yes, the headlights were on, as this was around 4:30am.

Another thing I can think of is that I took the car through a ubercarwash earlier that evening. Perhaps excess moisture got up somewhere it doesnt belong...

Different subject -
I recently had my oil changed my a nonVW mechanic. They used an oil filter they got from NAPA. I have no idea if it is the same filter VW uses, or if its even compatible.

To make matters even better, they seem to have overfilled it, the dipstick reads about 1" above the MAX mark. Such a waste of my sacred Delvac 1. My CCV bypass is emitting some nasty diesel oil smells.

 

[SoTxBill]

this can happen when there is a bad ground at the either the front or rear bulb...

the parking light is on and if the ground is loose or bad, the voltage will actually feed back through the turn circuit, and across to the other turn signal bulbs to find a ground... look for this first...