Hi, to test this you will need to test your inputs to the N10 combination relay from the wiper switch.
I'll give you some tests.
OK, I have multimeter, OK with probing for voltages etc.
Click here for the terminal readings at the N10 relay.
You will be testing pins 2, 11, 13, 14, 15 and 16 at the relay.
If you check for voltage at pin 14 with the wiper switch on high it will tell you if the switch is bad.
Actually that is the output from the relay. You want to test pin 15.
OK car is in garage, I'm just getting educated! Is N10 relay the one under the 2nd fuse panel? (the first one pops off, then you remove a couple of screws to expose the relays under the second one) Are the pins numbered, or is there a diagram to identify them?
The pins are numbered. I'll get you a picture of the relay.
Thanks, XXXXX XXXXX one I thought. I've never used these services before....do I work on the problem & get back to you as I diagnose, ie kep the chat open, or come back to it later?
You can reply back at any time if you need more help with this. Please don't forget to click Accept so I can get credit for my help today.
Looking closer at the schematic I think you might find that the wiper switch is the problem.
Click here for the complete schematic.
S4 is the wiper switch, M6/1 is the wiper motor.
pin #13 & #16 have 12V Pin #14 & #15 show no V
wow, wipers still work,(slow position only) even with relay removed...didn't think that could happen
that's why I was thinking the switch was bad.
It's a direct shot from the switch to the motor on low and high.
But you might also have a bad relay for the intermittent.
what do you suggest, replace the wiper selector/washer/turn signal arm? Can I do that without dissasemble of steering column & danger of airbags?
PS the windshield washer works fine, would just like to get both wipe speeds & intermiitant working. About a year ago, I noticed the selector, from slow to hi was VERY stiff, almost felt like I was going to break somethng by forcing it into another position.
It looks like a bad wiper switch. I'd test the voltage from the switch to the motor to be sure.
With the added symptom of the switch being hard to turn I'd say the switch is probably bad now.
Air bag must come off to replace the switch.
OK, if it is switch replace, & airbag...I'm not comfortable doing that, I've never dealt with airbags, but know they can be dangerous.
How can i test voltage from the switch to the motor
I see a square connector from motor wiring to vehicle harness, has 5 pins
You would just go to the connector under the dash coming from the switch and measure the voltage on the blue and the black wire coming from the switch. If you look at the schematic you will see that they change colors where they plug in under the dash at the bottom of the steering column. They change to a black/yellow/gray and a black/yellow/white wire.
You can test it there also.
Pin 3 and pin 5 are your low and high wires.
They should be a black/yellow/gray and a black/yellow/white wire.
pin #5 has power in slow position, no volts in high position except pin #4
I'd go ahead and replace the switch.
OK, the chat cost was less than the relay, which I was going to replace as the easiest, & a Hail Mary. Thanks, XXXXX XXXXX have an MB service manual, & am not great with electrical diagrams. I'll accept, that was worth $29.
Any idea of how many hours the MB shop bills for changing that switch?
It's a 2 hour labor operation to replace the switch.