I think my B and H relays in the fuse box of the driver side engine compartment were mixed up (2007 S550 W221). I was told B is for Airmatic compressor but don't know what H is for. They are both green and 5 legged.

The car ride is little rough, feels like suspensions are overpresurized. At first I thought the relay B was faulty so, I took that relay to the dealer and they gave me a replacement for $10 (part#A002 542 76 19).

Questions:
1. Does anyone know what relay H is for?
2. What is the correct part# for B relay?
3. Are B and H relay interchangable?

Please assist.

Thanks

 

B = compressor relay correct part #0025422319, H is circuit 50/starter.

 

Thank you much.

What is the Correct part # for H?

Thanks

 

same part # therefore they are interchangeable.

 

Thanks for your knowledge. It's very helpful.