Intermittent Wiper Repair

[marlinh]

I have one of these adjustable intermittent wiper switches that SynthDesign has also scored. The wipers work on slow and fast, but not on intermittent. I took it apart and confirmed that the relay does work. Does anyone know what the timer looks like? Or how to repair it?

http://www.tercel4wd.com/download/file. ... &mode=view



At the top of this photo is the relay, which operates. Does anyone know if the timer is the blue cylindrical thing below it?

[marlinh]

I have another intermittent wiper switch, non-adjustable type, that I want to repair as well. It works only on slow and fast, not intermittent. Does anyone know where the relay is located on that style of switch? I have taken it apart and cannot find anything that looks like a relay. In the past I have installed intermittent wiper switch in a DLX and no extra wiring was required. So, I assume the relay is internal. Any one repair one of these before?

[toyomonkey611]

my intermittent is cutting out, i hear it crackling somewhere inside the dash, not the steering column.

[marlinh]

Anyone with ideas?

[The Professor]

Anyone ever figure this out? My wipers are of the non-adjustable flavor. They do not auto-park when turned off and the "INT" and "LOW" settings are the same speed.

[Mark]

I'm guessing that the timing device in the wiper circuit is a capacitor. The time it takes to charge up is the delay between "wipes". You can fine tune the amount of time the capacitor takes to charge up by putting a resistor in the circuit. I think this is also how the timer for the turn signal lights works. In that case the bulbs are the resistors. If one of the bulbs burns out, the resistance value drops and the remaining turn signal bulb blinks twice as fast. In the above picture, I think the black cylindrical thing is the capacitor. By selecting different speeds for the wipers, I think you are switching the current to run through different resistors, which makes the capacitor charge up faster or slower. If one of the speeds isn't working, I'd guess that one of the resistors is burned out or the circuitry to that resistor is burned out/loose/corroded/disconnected. If the wipers work fine at at least one speed, I'd guess that the capacitor itself still works.