Mercedes heating elements..

[s p a c e m a n]

I've recently grabbed myself a '99 ML 4x4 thing to use over the winter, it has the standard occasional dashboard disco lights and various things don't work as you would expect, but I know why all of those separate things don't work. One thing has got me stumped though, none of the cabin heating elements work, the rear screen, both heated seats and the wing mirrors. All of the buttons light up and turn off with the timer, all of the fuses are good and every relay clicks (The rear screen and the seats are on seperate relays and the relays under the seats both click).

My next step would normally be checking the voltage on the relays, but they're all an absolute pig to get access to and as none of them work I'm guessing it would be something more centralised and before them in the circuit. Any ideas as I really can't be bothered to take a winter beater apart, but it's really bugging me and I want a toasty bum

[one eyed mick]

Common earths possible ?

[Jimmyarm]

Search the internet for a wiring diagram if you can find one, it will make the task much easier.

As a general rule of thumb, things like that are usually all 'seperate' circuits so one would expect the rear screen not working to have anything to do with the heated seats not working etc.

It is fairly easy to test if you have power to the heating elements once you locate the correct wiring plugs. On the rear screen and mirrors this should be easy (pop the trims around the rear screen off, pop the mirror glasses out).

FWIW I would expect all the actual elements to be goosed rather than a relay or fuse to be out, 9 times out of 10 it will be the most expensive bit that has failed !

Edited by Jimmyarm on Friday 30th October 11:00