Drivers turn signal doesn't blink with the lights on

[shift5]

'94 Blazer full size (2 door, 350, manual).

With the lights off, blinkers work great. No problems.

If I turn the lights on (headlights or even just parking lights), the amber fronts come on great. If i turn on the passenger signal, it works great. But if i turn the DRIVERS turn signal, it blinks fine in the dash, it works fine on the rear, but the front amber does nothing, just on solid. But i can hear the relay clicking normally.

Any ideas? I'm guessing it's a ground, but where would I look?

 

[delta_p]

Is the driver side marker lamp working well? A short there might cause what you describe. with the parks off, it should blink with the front lamps. With the parks or lights on, it should alternate blink with the front turns.

 

[shift5]

Just checked. Neither side marker works. Should I start by replacing those bulbs?

 

[delta_p]

I am just assuming the blazer wiring is the same as a C/K as that is what i have a schematic for. that is uses two dual filament bulbs each side for park/turn bulbs and a side marker powered via when the parks or headlight switch is on.
pull out the driver marker first and see if does the same issue as you were having?

 

[shift5]

So I've replaced both sidemarker bulbs.

Passenger side once again working perfectly. Turns on with lights and alternates with blinker.

Drivers side comes on with lights and actually blinks with blinker. But main signal still does nothing, just on solid.

 

[delta_p]

Check the driver side park/turn bulbs. There should be two filaments inside each bulb, the bulb should have two contact on the bottom. One filament lights up constantly with the parks/headlights on which i hope is what you refer to when says "stays on steady". The other filament burns very brightly and only during blinker on. make sure the correct bulbs and make sure filaments are not blown. make sure they are not in backwards somehow, there are two side prongs supposed to prevent that. Now i am confused too why the flasher relay wouldn't indicate it.

 

[shift5]

All 4 (2 on each side) bulbs are brand new as well. I'll try reversing them and seeing if they're possibly backwards I guess.

 

[shift5]

Well, that was it. the outside bulb on the drivers side was in backwards. All good now.