Drache

On my '71 coupe, the passenger-side front parking/turn signal lamp is quite a bit brighter than the one on the driver's side. I have swapped lamps with new 1157NA ones from the same package, and the problem remains. The lamps seems to operate and flash normally, and the clear lenses look identical with the same numbers on them. This is odd, but it's not the biggest mystery...

The fiber indicators for the front parking/turn lamps both illuminate when the parking lights are turned on, and the driver's side fiber indicator flashes normally when left turn signal is on. But when the right turn signal is on, the passenger's side fiber indicator does not flash! The lamp itself is flashing. I know the fiber is connected, because it illuminates when the parking lights are on.

How the heck could that one fiber not flash when the bulb flashes? :confused: And why is that passenger's side lamp brighter than the driver's side one?

Smokehouse69

The dimness might be because of low voltage to the bulb caused by a partial ground or a poor connection, get a VOHM meter and check both sockets, if the voltage is lower on the dim one then you have found your problem.
Now for the fiber optics, if the lamp is lit and the Fiber shows a light, then the fiber HAS TO BE BLINKING when the lamp is blinking! The only thing that could be preventing it from blinking is that it is plugged into the wrong socket. It could be that your blinker fiber is plugged into the headlight and causing the steady light.

lbell101

Directly above the bulb in the parking lights is a lens that sticks through the top of the housing. Check to see if those are clean. The fiber plugs into the lens from the top side. Make sure that they are pushed in all the way.

One of mine is brighter than the other but it's because the hole for the lens is directly above the bulb on one side and off center about an inch on the other side. I do find that strange too.

As far as the flashing problem - you got me - no idea!

Drache

Both fiber connectors are plugged in, but I haven't checked to see the cleanliness or alignment of either. I just went out and did a fiber "continuity test" by mounting a spotlight in front of each turn signal in turn, and each fiber indicator lights correctly when the spotlight is shining on the bulb end. I haven't yet checked the voltage to each lamp socket, but I did find that the side marker lamps had 198A bulbs installed instead of 168 bulbs. I replaced both of those, with no change in the brightness of the parking/turn lamps.

I know it's impossible, if the fiber is installed correctly and the lamp is flashing, that the fiber isn't flashing. That's what is boggling my mind!
The spotlight test says the proper fiber is in the proper hole. There has to be an error in my observations somewhere.

Smokehouse69

That is really weird! :crazy: Maybe you have some kind of space-time-light bending-blackhole-warp, going on in your fiber harness. :jester I wish I could think of some logical reason for the strangeness. If you can't find it, call the X-Files. :D

Drache

Solved.... so easy, I don't know why I failed to think it through before posting. The parking lamp on the passenger's side was wired backwards, making both filaments light when just the parking lights were turned on, therefore making it appear brighter. As for the fiber... now it illuminates when the turn signal is on, but I can't see it when the parking light is on. It's just so weak on that side, because of dirt or misalignment, that when only filament is lit it can't be seen. Whew no X files.