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Old Apr 18th, 2014, 11:53   #1
stephend
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Last Online: Dec 23rd, 2023 21:20
Join Date: Dec 2007
Location: S. Wales
Default intermittent front wipers not working

As per thread title, the front wipers on my 740 don't work on the intermittent setting. The intermittent wipe used to work, sometimes, by wiggling the wiper control stalk. I fitted a "new" (used) stalk, after which the intermittent setting stopped working altogether. However, I also fitted a new relay (genuine Volvo), and I can clearly hear that clicking at regular intervals with the stalk in the intermittent position, which seems to indicate that both stalk and relay are fine. I'm therefore guessing that the problem is the wiper motor, or possibly the cabling to it.

I've done a search on here, and came up with a number of references to a missing permanent live feed - but that seems to knock out the self-park function as well, where as mine self-park correctly.

My next step, I think, is to check voltages at the connector. I'm assuming that when the relay clicks on, one of the pins will step from 0 to 12 V, and then probably drop straight back down again, the self-park system controlling the rest of the sweep. If such a signal is present, then I guess it's definitely the motor at fault, otherwise the problem is probably a broken connection somewhere between the relay and the connector.

Does that sound vaguely sensible...? And can anyone suggest anything else I should be looking at, please?

All other wash/wipe functions, front and rear, are working correctly, by the way.
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1989 740 GL 2.0 estate
2000 V40 2.0 (gone)
2005 Toyota Avensis 2.0 estate (gone)
2012 Ford Mondeo 2.2 TDCi estate
1999 Land Rover Discovery 2 TD5
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