turn signal antics

My little red 1999 s10 has done a wierd deal ever since we got it a year ago...hadn't done anything about it since it seems harmless, but curious non the less!

During daytime driving when the headlights are off, signals all function normally. Checked all the bulbs...all are in working order. Fuses good.

When the headlights are on (either manually or auto) The right turn signal fast flashes...alternating with the running lights and only on the right side. Does this front and back. Also tends to dim the license plate light with the wink. Its like a 'wink-wink' light that emergency vehicles use.

I think sometimes this truck has developed a strange sense of humor.
I noticed when I replaced a headlamp bulb that the socket had one of the two terminal holes slightly darkened. Could this be affecting the flash sequence?

Thanks to all for any ideas!

Sounds kinda cute, I'd want to find out what's causing that and do it on the other side.

It still flashes, so it's legal

Wish that I could help you.

Check your grounding wires .. there may be one loose. Or the turn signal switch or circuit is broken or loose.

I think s10 people have the same sense of humor as their vehicles!!
I must admit, it turns heads, but I really don't want to turn the wrong heads...like those with ticket books!
I need to replace the sidelights...previous owner put red bulbs in and I understand that they're illegal...but it makes me wonder if it was used as some kind of first responce vehicle...maybe for a volunteer or something...and possibly they altered the signals, but didn't get that one put back right.
Thanks for the smile, OverBoardProject!!

Check your grounding wires .. there may be one loose. Or the turn signal switch or circuit is broken or loose.

Thanks for the advice! 80 deg. day today here in the midwest...I'll get out there and try to locate the grounds. Have a great day!

Also, check all your bulbs to see if there are working and working correctly. Sometimes one broken or wrong bulb can affect the whole circuit.

Thanks again dugie6551: I pulled out the headlamp assembly in the front and also the turn signal assembly. Checked those bulbs...they look good. Popped out the red bulb next to the headlamp...still does the same winky pattern. Wires in harnass all look good...I wasn't sure where to look for the ground wire to all this...I get nervous pulling out wires!
Haven't pulled out the rear light assembly yet...it does the same thing when the headlights are on. I'll check it in the morning.

When I turn the signal on, I hear the rapid click-click sound somewhere at the back of the engine (I'm an amateur) and I assume this is the signal switch?

At least it works well enough for me to go on a search mission in my spare time! I appreciate your time to respond...thanks again.

Just a thought litlred.

Your truck isn't wired for a trailer or camper is it?

If it is start looking there, and even remove those wires if you can

I wish I knew more about the truck's history...we bought it a year ago december. I don't believe it's ever pulled a trailer...and only because the rear bumper has never had the knock out hole punched for a ball hitch. Personally, I like the effect, but common sense tells me its just not normal...unless, of course, I could get the other side to do it!!
Thanks!