W220 airmatic fault

[Robiduff]

I took out the compressor and tested it, it ran ok. so i put i back. i saw the cable to the motor was a little burned in the connection. so i celaned it. then when measured the cable to the motor there was no power supplied. the fuses are ok, the relay is new, and the motor for the pump works, but there is no power in the connection to the pump, so maybe the cable is damaged?

 

[ItalianTuneUp]

Sounds like cable may have over heated when the relay died. Sounds like the cable is the problem now, like you say.

I changed my relay when I had the valve block replaced, as people said it's a cheap component to replace, and can save other potentially expensive compressor problems.

Edit: there's definitely power coming from the relay end?

 

[Robiduff]

I don't know since im only measuring at the motor. but there is power coming to the relay

 

[ItalianTuneUp]

What's the power flow: battery to relay to compressor fuse to compressor?

Edit: Or battery to compressor fuse to compressor relay to compressor?

Maybe removing the compressor fuse would answer this: if no juice at relay then fuse is first after the battery.

I expect the fuse is placed just before the compressor gets the power though.

 

[Robiduff]

I don't know, i think it's relay to fuse to compressor... but i don't see how it matters anyways since the fuse and relay are ok?

 

[ItalianTuneUp]

Ok then, so sounds like it must just be damaged wires to the compressor. New wires all round. Good luck.

 

[V12]

Fuse will be battery side of the relay normally.

 

[ItalianTuneUp]

I found this documentation for the W220 airmatic system, which provides lots of information:

http://www.benzworld.org/forums/att...ut-epoxy-fix-_w220-airmatic-documentation.pdf

Edit:

And this W220 encyclopedia is very useful too:

http://www.benzworld.org/forums/w220-s-class/1508080-w220-s-class-encyclopedia-start-here.html

 

[Robiduff]

Hi guys, last update, figured out the problem now. a previous owner had probably ahd som problems with it so he cut the wire in half on the middle and fixed it him self in a very bad way... some cheap connections and just some tape around it. so I replaced this with a propper concection and now it's working perfect thank you for helping

 

[ItalianTuneUp]

Great news! Luckily it didn't cost you an arm and a leg.