Turn signals and flashers stopped working

Hello, 2003 Green, V8, AC, 4WD, Step side bed Tundra. Joined this forum (my 1st) in January because my turn signals and flashers stopped working. The flasher relay would click but bulbs and dashboard indicators wouldn't come on. I replaced the flasher relay, no change. Replaced all 4 bulbs no change. Downloaded the FSM and wiring diagram from the forum. I'm getting the voltage readings according to the FSM. Tracked down the frame grounds and all appear good. Saw shifty's posts on "so you wanna buy a 1st Gen Tundra " and "Definitive 2000-2006 cab area leaks". Lots of good stuff. Led me to the Integration relay/fuse box under the driver's side dash. Pulled it out and I did have some minor corrosion. I cleaned that up and cleaned the connectors with a dental pick. No change. I ordered a new Integration relay/fuse box and another flasher relay. Replaced both today and still no change. The flasher relay stopped clicking a couple months ago. The turn signals and flashers are the only thing not working. My state inspection is due next month and I'm not sure what to try next. Appreciate any help.

 

Front only, rear only, or both front and rear?

 

Both front and rear

 

And you're 100% sure you checked the status of all fuses, both in the dash, and under the hood?

 

I checked the fuse for the flasher in the fuse box under the hood. The integration relay/fuse box came with all new fuses including the one for the turn signals.

 

Have you used a voltmeter to check voltages at fuse and relay terminals?

 

Yes using a digital multimeter. The wiring diagram service hints for Turn Signal Flasher circuit showed pin 4 (on the flasher relay) to ground always approximately 12vdc and pin 1 approximately 12vdc when ign switch on. Back in April when I checked they both read good. Today I decided to double check and now pin 1 reads 11 vdc but pin 4 is only reading about 4 vdc. Not sure if that's a technician induced error since I've been pulling the Integration relay/fuse box in and out or what?? I pulled the hazard fuse and I am getting 12vdc at the hazard fuse.

 

Maybe check the connections at the relay and try re-seating it. Also check the turn signal fuse.