intermittent rear wiper: how to?

[dlb]

i don't know about anyone else but i think our rear wiper controls suck. i never have a need for it to be anything more than intermittent and would like to make it so. is this as easy as pulling a relay from the wrecker and splicing it in to the wiring for the constant rear wiper button?

[4wdchico]

i don't know about anyone else but i think our rear wiper controls suck. i never have a need for it to be anything more than intermittent and would like to make it so. is this as easy as pulling a relay from the wrecker and splicing it in to the wiring for the constant rear wiper button?

Unless that relay has a timer unit built into it, no.

If you like to build electronic kits, this looks interesting: http://www.apogeekits.com/windshield_wiper_control.htm

[Neu]

I was wondering this too. I hate that it's on ALL the time. Once every 2 or 3 seconds would be more than good.

[kevbriga]

I also think the rear wiper controls suck! I live in the Pacific NW and drive in lots of rain. I noticed that even in heavy rain I only need the rear wiper to wipe periodically to maintain rear vision. I accomplish this with a troublesome push of the rear wiper mist button! sucks...and also keeps me less focused. I found a wiper motor timer circuit that is very analog and adjustable (no integrated circuits. Just transistors, resistors, a capacitor, and a potentiometer). I modified it to allow for intermittent wiping every 3 sec to about every 10 seconds. I will be able to adjust delay setting with a knob (potentiometer). I am going to wire it up today and share it assuming that it works. I'll post back with a link for you if it does.

[dlb]

very cool! i had given up on this project to focus on more pressing issues but it always bothered me. this is another one of the T4's quirks that toyota corrected on the corolla all-trac, which has both intermittent and constant settings for the rear wiper. i imagine the corolla's relay could be swapped into the T4 but i haven't looked at both to compare.

i'm very interested to see what you come up with, kevbriga.

[kevbriga]

Unfortunately every relay is just that, a relay. They need some sort of timer to control their switching. The T4's front wiper relay is mounted on a small printed circuit board behind the steering wheel and just in from the wiper control lever. I tried to find it in the factory service manual, but no go. It's not listed. I found it by listening for it with the intermittent wiper on and zeroing in on the relay clicking. This relay is soldered to the printed circuit board which also has the intermittent timer built into it. I bet the rear wiper for the corolla all-trac has a relay/ timer pcb board that you could swap and make work. Definitely not a pressing issue, but it's a challenge. Who doesn't want a good one every now and then.

[kevbriga]

Still haven't put the rear wiper circuit in yet. Lent the car out to a friend who needed a loaner for a minute. Should have the circuit in my tercel next week sometime. I shot a quick and crummy video while I tested my circuit and provided the link below. Always a good thing to make sure it works before making it permanent. I also provided a link to the modified circuit I made for the intermittent delay.

Circuit Schematic Link https://docs.google.com/open?id=0B2wrU_ ... HZwcTg4Vzg
Circuit Testing Video Link http://www.youtube.com/watch?v=7GbbZlc1 ... e=youtu.be

[kevbriga]

Tonight I finished installing the rear wiper delay circuit. Unfortunately this was not an easy install. I heavily modified the original wiring and added a few components. Being an electronics engineering technician I was able to bust this build out, but I probably won't post a wiring diagram because it would be daunting and complicated. Soon I will post a link to a video to show the new rear wiper motor operation.