i am working on a 200 mbz ml320 suv. both power seats will not work. I checked the fuses and they are good. I checked the grounds, and they are good. I even took the seat out of the car and tested itand its good. Just wanted to know if it could be a relay and something else i am not thinking of.thanks everyone.
Since you say it applies to both seats, the fault is most probably in a component common for both seat circuits. That would be the relay k1 (looking in the direction of travel it will be on the left side, top, close to row of fuses above it) in the right front footwell relay/fuse box. I presume you also have checked already the fuses f30 and f31 - they supply the power to both seat modules, there are orange (quite thick) wires coming from the fuse box to each seat. Please check if the seat modules are getting power. The other possibility is lack of seat activation signal (it comes from the AAM (All Activity Module) in the front left fuse box, via grey wire and it simply enables the seat by activating the relay k1. might want to try if applying battery power there (gray wire, connector 1, pin L) of the front footwell fusebox will make the seats work. Funny thing i was working on similar problem on W164 ML couple of days ago.The thing cooked down to faulty front module that did not supply the seat activation signal anymore.
yea if the seats work and the fuses are good its the relay or wiring.
same thing with my ml320 take the connectors apart and clean them with a little sand paper 100 grit
