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Wiper Motor Pulse board.

Acesneights1

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The one in my Burb crapped out. I bought another one but upon removal of the dead one I noticed the Diode looked like a bomb hit it? Look how the one lead is bent over the other way ?? Anybody have a schematic of a Pulse Board or know off hand the value of that diode ? I could not read the numers off the one in the new board and the one in the old baord is destroyed. I'd like to try fixing the old board for the heck of it.
 

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I took few pics when I resoldered the relay on mine last year. I'll check tonite to see if it I can read anything useful...
If the diode exploded, that usually means a dead short. Does the wiper motor still work?

Big diodes like that are used typically for power rectfication (such as alternator diodes) or used as a snubber. A snubber is used to "short circuit" and cancel the reverse-voltage spike when a energised coil of wire is de-energised. (This is what an ignition coil does in a gasser) In your case, it would be used to stop the wiper motor quickly so it doesn't spark across the contacts and continue to coast when power is turned off. Snubber diodes are also used across relays to prevent arching across the switch controlling the relay.

Mike
 
Unfortunately, I could not read any #'s from the diode in my pictures.
IMGP0917a.jpg

If you cannot get the diode #'s, I think a 5 amp 200 volt diode should be an adequate replacement.

Just my :2cents:
Mike
 
I found that when my board was actually failing even if I got it going the only thing that worked was the constant high speed setting. The board is to allow all the nice delay functions. When it was dirty I could get it to go by hitting the box and it would also work best with the constant settings because the motor contacts were always moving and slight points of dirty contact didnt stop it. But when I would put it on a delay it would go a couple times and then stop. So the symptoms were similar, but that getting it to work by smacking it was way more successful when it was dirty and the delay worked at some points.
 
Aces:
Ok, so the motor's good and no other visible cause for the diode to fail. Guess it's one of life's mysteries. Replace it and hope whatever caused it was a one-in-million occurance.

Buddy:
Check the board to see that the relay connections to the circuit board are still good. Over time, with the weight of the relay and vibrations, the solder connections fail and becomes intermittant. Thats what happened to mine.

Cheers.
Mike
 
Most times its the solder joints at the plug,clamp the plug in a vice and wiggle gently too check them. I've soldered quite a few.
 
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