Crazy turn signal!

[Raider]

Dangit!  FR signal was bad.  Tab cracked off the housing; wouldn't hold the lens and I'd guess it corroded inside.  Power was getting to the assembly, but no light.  No sweat, changed the whole thing.

Well, a little sweat, because I had to remove the dang fairing on the IS.  Ugh!  Only good news was that I got through the whole thing without swearing (but I did have to use JB Weld to put the brass fittings back in). 

All back together.  Running light is on; turn on signal and it works.  Turn it back off, and THE RUNNING LIGHT GOES OUT, TOO!  Try the same thing on the left side and same thing occurs.  I fiddle with the switch a bit and can get both running lights back on, but as soon as I use signal and cancel, same thing.   

Bad switch?

[vanagon40]

FYI,

I do not know about an Interstate, but on a Standard, when the turn signal is ON, the running light for that side only is OFF. Not sure how it works (or if Interstate is the same), but might help in figuring out the problem.

[Valker]

Did you change bulbs? If so, are you sure they are 1157 instead of 1156?

[The emperor has no clothes]

Did you change bulbs? If so, are you sure they are 1157 instead of 1156?

+1

[sandy]

Check for pinched wiring around the reassembly clamps. Also clean the turn signal switch internals.

[Raider]

Thanks all. I'll dig into it again this afternoon.

[Patrick]

I would it pretty hard to mix up 1157 and 1156, but, stranger things have happened.

But, if there is power to the contact I would think the issue would be some corrosion at the ground contact or a bad bulb. 

[indybobm]

Might be time to clean the TS switch in the left control. Not that hard to do. Gunked up with hard dried grease inside, contact cannot move as it should.