C3 side marker lamp flashing

[Kenneth T.]

I checked the archives and could not find info specific to my problem. I have a '71 and decided to do a lamp check as I am do for annual DMV inspection.

My signals are fine. All lights work. The hazzard flasher will cause the front and rear lamps to blink and the front side marker lamps. The rear side lamps will illuminate with the head light switch but not blink with the hazzard flasher.

I am pretty certain that they have only one filament, so if the lamp works in the headlight / parking light mode, it should flash as does the front. Right now I am confused Anyone had this problem before I have to go crawling down under? Thanks...

Ken

[Dick W.]

Re: C3 side marker lamp flashing

Front only side marker flashes. I do not have a copy of the wiring schemetic handy, but the front and rear are wired different.

[Terry M.]

Re: C3 side marker lamp flashing

The flashing front side marker lamps are a DOT requirement. There is no DOT requirement for the rear side marker lamps to flash -- and they don't. It doesn't matter if you are talking about a 1971 or 2001.

Lamp requirements for other than North America are different.

[Clark K.]

Re: C3 side marker lamp flashing

Kenneth, if my memory serves me on '70s Chevrolets, the front side-marker lights should flash when the turn signals are activated for that side of the car. My memory tells me that when the front signal is "on", the side marker for that side is "off" and vice versa. The intent was to signal other motorists at night that you are turning towards them. Sounds like the lights are working as designed, unless I misunderstood your problem. -Clark

[Kenneth T.]

Re: C3 side marker lamp flashing

Thanks guys for the replys. I have not had to use the emergency flashers in so many years, and my memory of what works is distant.

Terry, I pulled out my service manual and looked at the diagrams but stopped short of getting under the car when I saw you reply...whew, no advil tonight.

[Terry M.]

Re: C3 side marker lamp flashing

Clark raises a good point -- in that the side marker/front turn signal lamps flash differently depending if the parking/headlamps are on or not on 1971 and newer Corvettes.

If the parking/headlamps are illuminated (as if for night-time travel) the front turn signal and the side marker lamp blink alternately.

If the parking/headlamps are off (as if for day driving) the front turn signal and the side marked lamp blink in unison.

Check your American made driver car. It should work the same way -- it is the law.

This is a routine check for the operations teams during judging, and of course it is also done during the PV (Performance Verification) check.

I spent some time trying to describe this function in the NCRS 1968-1972 Operations and PV Manual. Now there is a book I would bet gets fewer sales than the Judging Reference Manual. Want to know how your early C3 should work? It is all in there -- of course I would be lying to you if I said there was no mistakes in the book, but there aren't too many.

[Kenneth T.]

Re: C3 side marker lamp flashing

Thanks Terry, they flash in unison without any lights on. They alternate if the headlights or parking lights are on. I am good to go for my DMV inspection. Ken

[Terry M.]

Re: C3 side marker lamp flashing

Good luck to you