Top Parking Light off, But Still Blinks

[Slabsides45]

Hi guys, first post after lurking for a while now, and it's a real head scratcher for me.

 

Happened to park in front of a glass window the other day, and noticed the passenger side top parking light was out.  Went and got a new bulb to replace it, and (after snaking my oversize hand through that cutout and a minor cuss fit) thought it was a done deal, but noticed again yesterday that it isn't working all the time.  Specifically, it:

1) comes on when I click the remote to lock or unlock, but after it blinks twice like all the others do, it goes off and the other 3 stay on;

2) when I crank the truck, it stays off while the other 3 are still on;

3) will blink normally if the right turn signal is on.

 

I called myself checking the fuses, and either didn't check the correct one or it isn't associated with a fuse issue.  Tried searching for an answer, and was unable to find anything quite like this.  Anyone got an easy answer?   Or even a hard answer?

[wforrest08]

First dbl check you got the right bulb # then try pulling the bulb out and turn it 180 reinstall, then try another bulb to make sure you didn’t get a dud (or the one from the other side) , and if it still don’t work you’ll need to check the socket with a test light for constant power with the lights on. 

 

The bulb has 2 filaments one for the blinker and one for the running light that’s why the blinker works.

[Slabsides45]

Thanks for your reply, I will get back in there and check on it.  

 

After going through all of this hassle, makes me wonder if I'd be better off to just put some LEDs in and call it good.  The engineer who came up with this access point needs a firm kick in the taint....

[Slabsides45]

Update, went back and reversed the bulb as suggested, swapped out bulb to another new one, neither helped.  

[Slabsides45]

Got fed up and went back out tonight.  Removed the grill and lower valance (terminology?), then the right headlight.  Cleaned everything off on the wiring harness, lots of grime but nothing obvious.  Did note that there was an extra twist in the wiring between upper and lower running lights, hence the reason I had so much trouble exteriorizing it at the outset of this debacle.  

 

After disassembly of everything I plugged the main harness back in and went thru every bulb, every direction possible.  When I finally got back to the OEM bulb (the one originally not working), it worked just right.  Unplugged it and tried the new bulbs, no go.  Old bulb again, yes.  New bulb(s), no.  Reassembled it all, tried it every possible way, worked fine.  

 

So, no idea what was wrong with the original bulb initially, but I suspect a short or either debris at some point that I shook loose with relentless anal retentive repetition of bulb rotation.  If it's a short, I'll soon see it and report back.  Thanks for all input and assistance.

[Slabsides45]

BTW, it was the Sylvania 7443 bulb 2 pack from Autozone that won't work with mine.  No idea if that's a one-off or what.