Resistor in washer pump wiring?

[brrian]

See below. There's a resistor poked into the wiring of my washer pump. I'm sure that's not factory? The pump isn't working so I'm going to take it all out and fix it but before I do, any idea why that would be there?

 

[John Canon]

That is a diode, not a resistor. A diode is used to allow current in one direction but not the other. Also a diode can be wired across an inductive load such as a motor or a relay coil. Make a wiring diagram of the wires, the pump, and the diode. That will show the answer. Normal current flows from the end with the silver band, through the diode, and out the other lead.

 

[ELCAM]

Thats a 1N1004 rectifier diode connected to the white +12V wire and the purple "hi" wire from the switch. I don't believe it is doing anything of value.

On the other connector that same white wire is also +12V and the pink wire is the wire to the switch for the washer pump.

Edited to add wiring diagram with diode, still don't think it does anything of value. Other cars have the same circuit and motor and did not use it.

The diode is not needed for the basic function of the circuit it is there to protect some part of that circuit or another circuit from voltage spikes when the circuit turns on and off.

https://www.arrow.com/en/research-and-events/articles/what-is-a-snubber

 

[John Canon]

As drawn, the diode is correctly wired across the wiper relay. That would reduce inductive kickback when the wiper switch is opened. It is used to reduce arcing across the switch contacts when the switch opens, much like a condensed wired across the points to absorb the kickback from the coil. My guess is it was added, depending on the particular relay and the particular switch. Not essential, but it may preserve the switch contacts.

 

[brrian]

I went to your snubber link and read and I basically understand it's purpose. I didn't expect it to be factory. Thank you!