I just bought my first SL500 last week and I love it! It is amazing. The only issue I need to fix is the windershield washer fluid. It doesn't work. When the "wash" feature is pushed in I can't even hear the motor run to squirt out the fluid. I'm good with diagnosing on older 123 chassis cars, but this is a little more technical and I was hoping someone has a "usual culprit" scenerio for this to make it easier for me.

 

Usually the pump itself..goes bad..but you could make sure the fuse is good. Or if you can check for voltage at the pump connector when operating the washers.

 

If your R129 still has the headlight washer, you can switch the pump to the windshield washer position. There are 2 pumps but are both the same (at least on my 96). There is a rubber grommet at the bottom that keeps the fluid in so I found the easiest way is to remove the reservoir, empty the contents (save or not) and switch the pumps. When you order a new one or 2 order new and extra grommets Perf.products is reasonable.

 

I checked the fuse and connected a test light to the connector that goes to the washer pump motor. It works. the pump motor does not. When I took it out I noticed to things. What is the orange connector that isn't connected to anything and the blue arrow is two wires connected together that come from the water hose itself. If either of these aren't apart of the solution then I would think that the motor itself is bad?

 

new motor $20 issues resolved