Wiper wiring

Hi guys! I have Honda wiper, that is connected common-positive. So slow and fast are switched by ground.

Solution 1) Add two relays for switch slow and fast by ground switched on by PMU. NO, NO, NO :-)

Solution 2) Rewire wiper motor:

NOW:

A - Fast - ground

B - Slow - ground

D - 12V

C - Ground

E - park switch output

My idea is change grounds for 12V on inputs, so wiper will move in opposite direction. But im lost in C. There is motor grounded so cant put 12V there.

Do you have experince with common- positive wiring wipers?

Thank you!

I usually do this with one relay switching between low/high via ground path. 87a connects to wiper low, an aux output from something CAN enabled controls the relay and so on.

The only issue I see switching polarity is that the wiper may not park correctly. Most of them will run in reverse no problem, they are a very simple DC motor.

Best way to find out is to test on whatever your car is. What chassis is this for?

Thank you. Its from Honda Accord 90-93. I tested switched polarity and I think everythink work right but motor is hotter and louder.

Hmm, perhaps the gears in that one are directional... probably best to just switch ground like OEM

My next step will be try switching slow and fast with PDM and reverse polarity by relays. I will see.

Which PDM? A half bridge output will allow either a switch to positive or switch to ground.