Slow Rotor

As the question states. My S4 is going in for a safety check. The wipers were having the usual issue these things have of only working on low, so I went to the effort of swapping in the switch out of my S5 which worked last time I drove it (although it was a couple of months now) and the wipers are still only working on speed 1. Anything else it could be? It seems very unlikely my working switch crapped out whilst the car was sitting there

Odd the rear wipers not working now either but the washer pump is. Also the horn has died, originally I could hear the relay clicking but now I can't, is it possible the CPU is the problem?

clokker

iTrader: (2)

I don't think S4 and S5 switchgear is interchangeable.
Yes, the connectors are the same but the wiring is not (a repin would fix that though).

Other than that yes, the wiper motor itself can fail.
I'd imagine that it's rare (Hailers says "Never") but our FD wiper motor died, so...

satch

iTrader: (1)

The horn relay is found in the CPU but the wipers are not related to the CPU. The largest of the three plugs connected to the CPU houses the wires related to the horn. If you jumper a ground wire to the Green/Orange wire and the horn sounds off then the problem is likely associated with the G/O wire not receiving the proper ground signal from the horn switch in the steering wheel.

If there is a problematic wire in the harness then that could explain why the newer wiper switch is now acting up.

Scrims

iTrader: (2)

Don't forget the infamous cold solder joints. My horn didn't work when I first got the car, so I cracked open the CPU and re-soldered the pin joints and all is wonderful now. Mind you this means removing the old solder and applying new, not simply melting the old and letting it re-form.
As for the wiper, replacing the relay isn't that big of a deal as long as you have a little soldering experience (which IMO you should have anyways owning one of these cars), or you could have it replaced for you by one of the forum members who do such work.

Slow Rotor

I'm just going to bump this old thread here. My horn is fixed and it was some dry solder joints in the CPU. I was unable to get a relay over here for the wiper switch in a hurry as I have sold the car this weekend and need it to pass roadworthy. I just installed the new switch and the wipers still only work on one speed. And the rear still doesn't work. I thought I may have a dud switch so I swapped in one out of a vert which has had the relay replaced. Wipers still only work on one speed. Does this mean the only thing left that it could be is the motor?

Slow Rotor

I feel like punching the previous owner in the face. Pulled the motor from my s5 to plug it in and see if it was faulty or a wiring issue with the s4 and I notice a wire not plugged into the plug on the wiper motor, a blue/red one with tape over the end. Could someone really be that stupid to do that? I plugged it back in and boom wipers work on all speeds. **** whoever did that to me.

HAILERS2

Key to ON.

Go to the front wiper motor. Leave it's electrical plug ON the motor.

Put the wiper blades up in the air, not on the windshield.

Get a piece of elect wire bare at each end.

One end of that wire to a ground........like the engine manifold or bare chassis area or intake dynamic chamber etc.

Touch the other end or that wire in the back of the wiper motor electrical plug where there is a Blue/Red wire.

When you ground that Blue/Red wire using your piece of elctrical wire.........the wiper motor should spin and make the wipers move.

Do the same thing but at the Blue/White wire in the electrical plug. Wiper should move when you do that.

L/R is for high speed............L/W is for low speed.

All the motor is looking for is a ground from the switch to either the L/R or the L/W wire at the motor to make them run. The voltage is already there on the pure Blue wire if the key is ON or better.

Pele

iTrader: (28)

They are. I test S5 switches in my car.