boaterboy Posted July 24, 2018 Share Posted July 24, 2018 I am trying to identify why the headlight washers on my Discovery 2 will not work. What I do know is that having removed the outlet pipe on the pump and operated the system no water is pumped out - although every third cycle the headlights dim very slightly (when operating on the battery only) indicating some current draw? Screen (front & rear) washers operate correctly. My electrical knowledge is extremely limited but I do see that the circuit incorporates - BCU - pump relay - pump Whilst I have neither the knowledge nor the equipment to do the tests would anyone know if it would be possible for someone with the know-how and test gear to identify which of the above components has failed? I would hate to buy a new pump only to find that something else in the circuit had failed. Thank you for your advice which will be gratefully received. Quote Link to comment Share on other sites More sharing options...
dave88sw Posted July 24, 2018 Share Posted July 24, 2018 Anyone with a multimeter should be able to test that there is 12v at the pump when the washers are operated, that should be the first test. If there is you can confidently say that the pump is seized, if not, your problem is elsewhere. If you haven't got a multimeter, your best bet is to find a test light (or make one, i just use an old sidelight bulb holder with some tails of wire) and put it across the 2 contacts of the connector on the headlight washer pump. Quote Link to comment Share on other sites More sharing options...
boaterboy Posted July 25, 2018 Author Share Posted July 25, 2018 Thank you for your speedy reply, dave88sw. I'll certainly set up a test as you outline. I do know that the headlight washers should work every third time that the windscreen washers operate. So I guess that, if power is available at the pump, then the bulb will only light once in every three occasions? Would you know if it is the BCU which controls the one in three action? Also, where is the relay located should I need to find it, later? Thank you for your help, it's very much appreciated. Quote Link to comment Share on other sites More sharing options...
sierrafery Posted July 26, 2018 Share Posted July 26, 2018 Hi, relay R3 in the engine bay fusebox is for the headlamp powerwash and it is managed by the BCU, the power comes from fuse F4, to check the pump you can remove the relay and bridge the perpendicular cavities in the fusebox, then if the pump is good and the ciurcuit to it not interrupted it should turn over Quote Link to comment Share on other sites More sharing options...
BogMonster Posted July 27, 2018 Share Posted July 27, 2018 Best thing you can do is leave them broken. They are completely useless at everything except emptying the tank twice as fast! I disconnected mine when the vehicle was new - just took the fuse out. Quote Link to comment Share on other sites More sharing options...
boaterboy Posted July 28, 2018 Author Share Posted July 28, 2018 sierrafery - very many thanks for explaining the circuit and the test tip. I appreciated it. BogMaster - I liked your approach to the problem! However, having an aversion to something fitted which is not working plus having the vehicle from new and my trying to keep is 'as original' as possible (a odd trait of mine!) I think I will try to fix and should I fail then I will adopt you approach. Very many thanks, anyway. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted July 28, 2018 Share Posted July 28, 2018 (edited) . Edited July 28, 2018 by Ally V8 Quote Link to comment Share on other sites More sharing options...
boaterboy Posted July 30, 2018 Author Share Posted July 30, 2018 Ally V8 - Which part(s) of the above conversation was edited, please? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 30, 2018 Share Posted July 30, 2018 Just his post, he decided to remove it. Quote Link to comment Share on other sites More sharing options...
boaterboy Posted July 31, 2018 Author Share Posted July 31, 2018 Thank you for that, Bowie69. Hadn't come across that before, something I've learned today. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted July 31, 2018 Share Posted July 31, 2018 Sorry about the confusion, I wrote a post which was incorrect. Caused by a well known garage/tyre type chain failing a Disco on non working headlamp washers. They shouldn't have done,I checked on the Mot testers manual and they are only required to work after 2009 apparently. Job to keep up with Mot rules,even number plate lamps have had their rules changed... Quote Link to comment Share on other sites More sharing options...
boaterboy Posted July 31, 2018 Author Share Posted July 31, 2018 No probs. Out of interest, I wonder if is it permitted to remove a headlamp washer assembly on a post-2009 vehicle and hence not have anything to fail on the Mot? Quote Link to comment Share on other sites More sharing options...
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