DIY Intermittent Wiper Delay for local Terrano

[Chef Noob]

Good Day mga brothers,
I just would like to share another DIY project for our rigs...

Since before, all of my cars had an intermittent wiper delay system installed...except for the Terrano. Honestly, I never really thought I would require one, not until I had this rig. You see, local Terranos were designed to be rugged...straight to the point...and no complicated electronics. This works for most people but since we live in a country that drizzles half the time, I had to say that this feature is not only meant for ease, but could be considered as required.

I called up the casa and inquired about it. They informed me that they have to order a module box in Japan plus I had to replace my existing wiper control switch. EXPENSIVE!

So I went to google & found a decent schematic which I could use to build my own one.
http://www.techlib.com/files/wiperkik.pdf

After a quick run to the electronic store & 3 hours of tinkering, I was able to make one.
Below is a picture and a video of my first prototype.
‪DIY wiper delay‬‏ - YouTube


Now, this one can already be integrated to the wipers...you just need to install a switch so that you can turn it on everytime you want the delay...However, since I am a bit of a purist and does not like the idea of a box mounted on my cockpit(plus the hassle of flicking the switch to turn it on)... I decided to integrate it to my existing wiper control... Easy right? NOT A CHANCE.

You see, this is where all things got really complicated. During this time, I could not help myself but develop a love-hate relationship with Nissan Engineering. You love them for creating a very unique automobile...but at the same time hate them for not just adapting an existing system used by other car makers...thus making it harder to modify! (A few examples? Nissan Lugnut, Some relays...maybe thats why Nissan is charging a lot when it comes to accessories).

First and foremost, they adapted a ground-switching design. Traditionally, wiper systems are designed this way:
When you switch the control to first position, they send current to the motor with the corresponding lead(depending on the speed you want) to make it run.
So that means when the switch is off, no power is sent to the motor. This means that you only have to control the timing sequence then your good to go.Simple!

But NISSAN...all wires coming in and out of the wiper motor are live! Every time you flick the switch, it just grounds certain combination of wires to make your motor move. That means the module I should design SHOULD BE ground triggered also...which is completely opposite from the one I had! :firefirefire:

Another problem with their design is, if you integrate the module to the live wire...when the motor runs, it drops the voltage to as low as 3 volts...thus disabling power to your module. One option is attaching it to a stable power source but this wont work since this will make the module "ON" all the time, even if the wiper switch is off.

After a week of routing, rerouting, theorizing,etc... I was able to find a good combination of capacitors, resistors, potentiometers, transistors, etc.

Below are photos of how I installed it.






Also, a video of my now working intermittent delay. (just don't mind the Ice cream vendor)
‪DIY Wiper Delay for NissanPathfinder/Terrano‬‏ - YouTube

Originally, we have 3 settings for our wiper...Off, 1 & 2.
Now, my #1 can be controlled intermittently...with a frequency ranging between 1sec - 18 seconds per swipe.
My #2 and OFF still remains the same. Also, the windshield washer is still intact.

GLITCH:
One glitch I noticed is that the countdown comes before the activation of the wipers...Meaning, if you set the knob to about 10 secs delay then flick the switch...it will count up to 10 FIRST then activate the motor. What I do to counter this is to set the knob all the way to the right (max) so that when you switch it on, it will swipe within 1 sec upon activation. Unfortunately, this can not be remedied.

To those who wish to create one, you can use any means to route it. You can even use a breadboard if you dont know how to make your own PCB.

Hope nakatulong to sa inyo!

[oj88]

Nice DIY. But wouldn't a 555 timer IC wired in astable mode be a better approach? I'm pretty sure it doesn't have the glitch you described.

[cocoy]

great job sir.. just want to know though.. wala kaya surplus module from banawe?

[Chef Noob]

*OJ88
Actually, the design I used works similarly with a 555 timer IC. The problem i was facing was the Nissan control system works by ground switching...so reversing the function of the timer IC would mean installing more transistors to bias the whole thing...plus, you need a consistent power source when using the IC since it will just reset the timer if it fluctuates - thus making integration to my existing switch not possible.
But if your system does not work like mine, then I will suggest that the 555 timer is your best bet.

*Cocoy
There are surplus modules found in banawe... if you're willing to settle for an upside-down switch. (If I'm not mistaken, wiper controls from right-hand vehicles are on the left.