86 K5 Blinker issues..help please

[CamSmoky]

Just purchased a half restored lifted 86 K5 blazer(Silverado package) with its fair share of quirks. I have worked many of them out but need some help with the blinker electrical situation. Here is what is going on.

The truck had no bulbs in the front marker lights in the grille, but everything else as far as lights work. I put bulbs in the front marker lights, and as soon as I did, when I turn on the either side blinker now with the bulbs in, all 4 flashers blink just as if the hazards are on. I take the bulbs back out of front markers, everything works fine with blinkers(side front markers flash fine as well as rear).
I am a novice at electrical and this one for some reason has me stumped. It probably is brutally easy, but I just am frustrated now after fixing a million other things and maybe not thinking clearly.

Any ideas?
Thanks in advance from Kansas

[tobiahr]

they may be sharing a ground that has come loose. if that happened the circuit would complete through the other side (drivers side would complete through passenger side) causing them to light as well. The same thing would happen if they are grounded to each other instead of the vehicle.

I think