Taillights went out, it's not the bulbs!!

[MJRemi]

So my dash and tail lights worked when I dropped off my truck (oh shaddap ) for a serious coolant leak which turned out to be the water pump. While replacing the pump, the shop also replaced my serpentine belt and thermostat. Upon picking up the truck (dark out) I watched my dash lights quickly dim and go dark which I confirmed at home that my taillights were out. Next day testing showed my brake lights, back ups, and hazard/turn lights all work. Still no parking lights. I checked the bulbs. Replaced two. I checked the parking lamp fuse (amongst others) and replaced it. No taillights still. During this round, my L. turn signal stays solid but the R. flashes.

Coincidence? I think not! But you know the shop will deny any connection to the lights. What should I check next and what ,if anything, might the shop have done to trigger this perfect electrical storm? Any input is welcome.

[Pete M]

I would check the the front indicator sockets for corrosion. also, there's a harness connector right behind that rear drivers tire that likes to corrode and cut power to the rear. got a trailer harness spliced in?

[MJRemi]

Yeah, I'm gonna double check all connectors/sockets and probably just replace them all since they are fairly cheap. It baffles me how the other lamp functions work off the same bulbs but the parking light mode is kaput. I'll keep checking and hopefully can avoid a visit to an auto electric shop.

[Pete M]

because they use different wires coming from the cab.

[MJRemi]

Got it!! The ground wire from the battery had been yanked off the connector during the water pump replacement. I reconnected it and replaced the 3rd blown parking lamp fuse and voila. I will still replace all the bulb connectors due to them looking quite crappy. Thanks for the input.

[Pete M]

:clapping: