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Hey guys. I can’t seem to get my instrument cluster illumination lights to work. My turn signals and high beam, etc all work. I have swapped out dimmer switches and gauge clusters and they still don’t work. Tested all pins in the dimmer switch and all have 12v. I’m at a loss here
First thing to check is parking lights / taillights (NOT the stop lights). There's an upstream fuse that energizes them all. There's also a fuse downstream of that that's specific to the dash lights. FInally, consider the dimmer in the headlight switch.
Alright fellas, I’m making some progress (hopefully). Tail lights work, brake lights work, the plunger on the pedal works, fuse 13 is good, BUT I don’t have a 3rd brake light (which is surprising as this usually causes the torque converter to not lock up). I’m not getting power to the socket, but I am at the cargo lights. I tore my truck apart following that wire and found out it runs along the floor board to the B pillar then starts heading towards the middle of the truck (WTF?) and gave up following it.
At this point, I’m STILL at a loss. Why would every other light on the truck work correctly, but not the 3rd brake light?
Nah it’s a common thing lol. If your third brake light bulb goes out, it affects the trans. I was pulling a trailer once and the trailer LEDs shorted out and wouldn’t let the TC lock up. The computer thinks your tapping the brakes and unlocks the converter.
I checked the socket and it looks fine. Put a volt meter on it and it’s not getting much voltage. Like .05 volts (could have been I didn’t have a good ground with my volt meter though). I swapped the bulb from the cargo lights just to be sure and it still didn’t work. It appears someone rewired a socket on at some point and did an ok job soldering it but they just wrapped it in black tape… I cut the soldered parts out, used an uninsulated butt connector and heat shrink to rule it out
I got called into work mid-diagnosis and it’s gonna be crummy weather the next few days. I’m going to triple check the socket itself when the weather breaks to make sure it’s not the culprit
Nah it’s a common thing lol. If your third brake light bulb goes out, it affects the trans. I was pulling a trailer once and the trailer LEDs shorted out and wouldn’t let the TC lock up. The computer thinks your tapping the brakes and unlocks the converter.
Wow that’s wild, I guess it makes sense tho you would think Ford would have come up with a better way to determine if you’re tapping the brakes!
Good luck to you, that’s all the info I’ve ever found on it! Sure like to know how you get it done!