1999 4x4 Blazer

My right turn signal has issues every now and then. It blinks fast as if a bulb was out, and sometimes it works normally like it should. Both front and rear bulbs are good and illuminating.

Also, I have wiper issues, and my right signal in dash light illuminates when I blow the horn.

I'm thinking a bad turn signal switch? However, my left signal is fine.

The horn and the signal light has thrown me for a loop.

 

For the signals I'd check/replace the flasher unit of you've checked all the lights & made sure they're all ok. Sometimes a halogen/filament bulb will work ok but then fail causing the fast flasher. That's because the filament has broken & is bouncing around, making & breaking contact.

For the signal lighting when the horn is blown I'd look for a ground issue. Something is causing the light to ground out & light up when the horn is hit IMO.
Wire insulation broken, cracked etc perhaps.
Have you or someone mucked around under the dash or in the steering column in the recent past?

 

I haven't yet, but the truck has 245k on it, so I'm sure someone has before. Where is the flasher unit located?

I'll get in the steering column and take a look around for something cracked cause I bet your right. I didn't think if a short/ground problem.

 

The flasher should be behind the glove box. On my '02 I pull a plastic flap inside the glove box upper left side & drop it open, the flasher is in there. Just turn the signals on & follow the clicking. A new one cost me $22 I think.

 

Don't overlook the small corner bulbs up front. Compare side to side looking at every filament that illuminates and when they illuminate. Compare the hazard operation and the turn operation as there is a difference between the operations. You may just have a corroded socket somewhere with an intermittent fault.