Alright long story short, someone broke into my truck while I was doing work training at a college, ended up getting an alarm installed later and slowly started having issues with the rear lights. I'm pretty confident the alarm has nothing to do with why my turn signals aren't working (they're solid in the front, and it looks like the rear lights are unsuccessfully trying to flash, you can see they're trying to do something but it's more of a flickering light) when I traced the shops wiring they hooked them up to the switch rather than just the lights itself but all this started within a week of the alarm install.
Anyhow so as it sits now if I use my turn signals the front bumper lights turn on solid like I have a bad bulb. I swear when I got this truck a year ago the side marker next to the headlights turned on as well but I can't verify it as apparently there is wiring issues with all the older Blazers out here (i live in the PNW, lots of rain) and I can't for the life of me figure out what each individual light is called (courtesy lights, marker lights etc can't figure out which is which) speaking of rain, when it was raining heavily out BEFORE the rear lights started this my left turn signal would flash as normal and sort of trail off and become solid after 10-12 flashes. Right signal normal. So now I have to assume a short somewhere, maybe a bad ground. I go to look in the repair manual I have and it has the most minimal information I have ever seen in a repair manual. I do have a test light but no multimeter since that's MIA. My truck also has a trailer harness wrapped up on the tow ball, kinda wondering if this could be part of my issue (my brain tells me open harness = water in wiring = shorts in wiring right?) if anyone has any other ideas for me let me know, I'm about to see if I can do something with that harness first

 

Forgot to add the hazards do work- as long as engine is off. Otherwise they are solid. Got called into work so haven't had a chance to trace the trailer harness as of yet.

 

Start with the trailer wiring. Might just take some looking around to see if you spot anything not right.

 

I had a chance to look at the trailer wiring, not horribly happy. Whoever installed them piggybacked each socket so I have a total of 5 random wires hanging out around my tailgate(and as I have dogs that gets opened regularly) so I'm gonna end up removing all of it since they didn't use the right colors - anything visible above the tailgate is either white or green, the ground is white as well and the wiring below is what I'm pretty sure are the correct colors going to the plug (red, white, black and yellow I believe) and I just don't see myself hauling a trailer any time soon. The wires also just come out of the tail lights at the sides of the tailgate, no one bothered to unscrew a couple things and protect these now hard and prob brittle wires. Hopefully I won't have to spend my only day off rewiring my rear lights. I'll update once that's all said and done.

 

Sounds like you could have found your problem.
I hate when you get a vehicle and later down the road realize that the PO botched wiring something up. At the time they were like "this will work" but did not think about anything down the road.

I hope removing those wires fixes your issue. Sounds like it was shorting out to me.

 

Alrighty so been a bit and finally had time to look to this (not my only rig but damnit I'd rather drive this one) found the pass rear turn bulb blown, replaced that now it lights up when I turn the alarm on/off however still solid when trying to turn. Starting to think the multifunction switch is to blame. I do have the phantom wipers but we're talking once or twice in six months not daily. Not hearing the clicking when using the turn signals either If that matters. I have one last bulb that's blown but I dont think it's part of the turn signal system (it's the corner light next to the headlamp on the drivers side) either way if it were it wouldn't affect both sides just the one it's on (or at least that's how my old 88 camaro was) any way to test the multifunction switch without a multimeter or buying a new one? I'm prepping to move next month and the only things I have readily avail are standard hand tools and a test light. The switch is the next thing to replace on my list once I get moved but it hasn't been bugging me unless that thing is why I dont have turn signals.

 

I would try replacing the flasher module first. A lot easier to change than the switch at this point.

 

My hazards work, if the flasher itself was bad wouldn't that not work as well?

 

I believe there are 2 flashers. The one on the fuse panel should be the one for the signals.