Hi,

Have a new to me CLK 350 with dead windshield wipers. I understand the process to diagnose is

1: Check fuse + power @ fuse box
2: check power @ Wiper Motor
3: Check Wiper relays
4: Check column switch

Question - How do I check the relays? There are two.

And how do I test the column switch?

Thanks!

A way to see if you have a bad relay is to buy a new one and see if it fixes the problem. Not strictly a test, but ruling out by process of elimination.

Another suggestion is to use a multimeter on the relay contacts in the fuse box/SAM. However I don’t know if some relay contacts need to be in place to test the circuit so this may not be 100% successful.

Can you pull the power connector off the motor and access the contacts with a multimeter?

Checking other items requires the wiring diagram to see where cables are terminated. Or pull the harness off the switch, if accessible, and use a multimeter.

Common theme here is a multimeter. I like my old Fluke, purchased about 10 years ago but it is the decades-old design.

Thanks Chassis, I'm going to check for voltage @ the motor and will report back.