So I took my truck in for a full detail today, including the engine bay, and now I have no turn signals or brake lights, though the 3rd brake light still works. Took my multimeter to both fuse boxes and all fuses are good, tested the bulbs and they are good, the running lights all work so no bad wires, even replaced relay #1 in the fuse box under the dash kick panel. Really at a loss here as to what else it could be. I've only had this truck for 5 days, so not at all familiar with it, or Fords in general so any help will be greatly appreciated!

 

My guess is they removed your tail lights to detail it and didnt connect them back up when they reinstalled them.

 

nah, I pulled the tails off to check the connections and bulbs, everything was fine. Plus my running lights all come on when the parking lights are on.

 

Something came undone somewhere, where, I couldn't tell yaa. If they detailed under the hood did they use high pressure water??

 

Do your front turn signals work ???

 

yes I think they did, but I checked the fuse box and all the fuses where fine.

no, I didn't even get the indicator in the cluster blinking, or coming on at all.

 

I have learned never pressure wash in your engine bay #1!

I would go back to them and see EXACTLY what they did and tell them.

 

I plan to go talk to them tomorrow, but I still need to find the fault. I was hoping someone would know if there are any links in the system that would be affected by the bay being power washed. I can't figure out what else to check that would cause brake lights and turn signals to stop functioning completely.

 

If I remember right you only have one fuse box and it is under your dash so I would look real hard for a partly unplug plug or one that is socked in water under your hood. Either way double cheak fuse #27 & #18 see if they have power to the line side of the fuse.
BTW is this a7.3 or a6.0

 

It's a 7.3, and I have a fuse box under the hood next to the master and one under the dash. I tested each fuse with a continuity tester, and all checked out fine. I'll double check 27 and 18 now.

 

You wanna check 13 under dash. 20 22 under hood.

 

If you have NO rear lights in the back Check for a ground failure.

 

It is really hard to help when im not there seeing whats going on. I dont really wanna go outside and tear mine apart to see if i can brake it! But im trying to help man. More info is needed really like out of all 4 lights what works and what dosent. illumination for head lights, turn signals front and back, rear tail lights, brake lights in rear, license plate lights, side markers and bottom of head lamp markers...

 

4 ways as well. do they light up at all, do hey blink all llike suppsed to? If 4 ways blink all its a switch problem. if tail lights work its a brake like switch problem. if its switch problems then you gotta see how they connect. IF they dont work at all its a power/ground error.

 

If turn signals or 4 ways dont work check this:
Turn signal hazard flasher- relay # 1 behind glovebox on 2002 models. Before that to the right of the steering column. To test it put on your 4 ways and listen for clicking noises.