(Almost) OEM Intermittent Wipers for the FJ40 (1 Viewer)

myquestoyota

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Mar 1, 2010
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I am using the one that coolerman wired up for me and very glad that I have it. That being said it is not without it's petty annoyance of cycling the wipers every time I start the engine. A couple of passes and then they park, most of the time close to the right spot. I had to adjust the park tabs to the very end of the stroke so sometimes they don't park perfectly. In this climate intermittent wipers are keeping me from over using a 40 year old wiper switch. Anxiously awaiting the next generation of wipers from @unixman.
 
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May 11, 2013
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MD
Sorry for the long absence. Life gets in the way of what I want to do way too often lately. I finished the revision to the intermittent wiper unit. I added a metal-foil resistor and polyester capacitor to each relay. This RC snubber prevents arcing that could occur whenever the relay opens. The uC side has a resettable fuse, reverse-polarity protection, and a TVS diode for transient voltage protection. The voltage regulator is designed for much larger loads and uses the ground plane as a heatsink so it produces virtually no heat. The 12V side has an 8A fuse and the wiper motor traces were increased to handle a sustained 8A with very little (10ºC) heat rise. According to Coolerman, the wiper motor can pull up to 3.5A under heavy load with a stall current maybe twice that. If you see over 8A, you have a real problem somewhere. I need to take time to modify some of the uC firmware. It works fine, but it takes more of the memory space than I want it to.

There is a two-pin header that I use for testing. With a USB to TTL cable you can see what the uC is doing. The screenshot below shows the ignition switched on, and the wiper switch pulled to slow and quickly back to off twice ~3 seconds apart. This put the wipers in intermittent mode sweeping with a ~3-second interval.

I just assembled one, tested it, and will mail it to Coolerman next week. When I get his feedback, I’ll press ahead with any necessary changes and a final version. I'll try not to disappear again...

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myquestoyota

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Western WA
I will take one as well. I'm still using the one that coolerman worked up for me but would like one that does not cycle the wipers when I start it.
 

Coolerman

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I have received the unit, and preliminary testing on a 1976 harness (using my 1971 wiper motor and wiper switch and a lot of jumpers :D), proves it does indeed work! I will test it out on my 1978 and 1972 harnesses next.
 

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