I recently purchased an 03 Excursion. There were no problems with the vehicle until I just had the tranmission and 4wd serviced and changed over to synthetic fluids. We also received our first snow the day I got it back from the shop.

After driving in the snow for a day the dash lights, fog lights, and tail lights all stopped working. I have checked the fuses and don't see a problem there. Can anyone advise where to look next. Thanks

 

Are you sure the fuses are ok ??

 

I have checked them all and see no problem with any. I pulled the two for instrument cluster, the one for fog lights, and the one for external lights. No issues with any of them. Could there be a grounding issue that is associated with only these things hooked into the trailer brake wiring?