i have been over and under my 99 c280 and can not figure out why the power seats work when they want to, so here's what i've done so far after using the search option........replaced the aux relay in the trunk next to the battery, checked all fuses, and examined all wiring and harnesses under the seats. here's where i am baffled because i was thinking after all the troubleshooting that i had an intermittent open somewhere (broke/bad wire), but that would only affect the seat with the problem, whereas when mine won't work it affects both seats. Now i'm thinking that there may be another relay coming from the power source, but i can't find one. Can anyone enlighten me?