Weird turn signal problem

[Breadstick]

I just bought my 64 C10 and I have a weird turn signal problem. Both rear turn signals work just the way they should. The left turn signal in the front works just fine, but when I turn on the right turn turn signal, both front turn signals blink. I did a pretty lengthy search but I can't find anything that looks like my problem. Does anyone have any ideas what might cause this?

[losthope]

check and see if you have the right bulbs in the socket on the right side! when i got my truck i had a similar thing going on but on the rear lights, previous owner stuck a single filament bulb in the dual filament socket so it was making contact to both contacts in the socket back feeding the power to the other light making it light up...........almost went nuts trying to find it, never wish i could go back in time to punch somebody in the face so bad...

[steverino66]

Originally Posted by losthope

check and see if you have the right bulbs in the socket on the right side!

exactly - you have a single contact bulb that's touching both prongs in the socket where you should have a double contact

[yelmer]

did you put in i new turn signal switch?

[tincan1966]

Are they both flashing bright? If they both flash, but dimly, make sure the right side is grounded good(after making sure correct bulb is instaled) The housings do not ground well to the hood only, and sometimes will backfeed thru the park light circuit,causing both sides to flash. pretty common for ground probs on these trucks.

[oldgoalie]

My 65 did this it was a bad ground at the light. Also had both fronts do this once. The hood wasn't grounded well enough. It is grounded through the hinges and they get dirty. Spayed them with a little WD40 raised it up and down a few times and everthing seems to be working well.