Jim Mason Posted July 3, 2021 Share Posted July 3, 2021 Hi there, Strange problem recently occured. Not used Landy (Disco 1 - 300 Tdi) as frequently as before lockdown. Now second ignition is switched on wipers instantly start independant of switch position. Relay is functional, feel it switching positions, rain stopped play so not checked beleive i must have perminant supply now to relay. Speed settings are functional, has switch failed? Haynes manual not very clear, does anyone have a clear drawing or some pointers on where to look for the fault. Trying not to rip the dash etc to pieces. Quote Link to comment Share on other sites More sharing options...
teabag Posted July 5, 2021 Share Posted July 5, 2021 Its not impossible for the wiper switch position to be faulty with the contact stuck in a made position, so further investigation with a multi meter is required. Below is a diagram taking from LRs electrical workshop manual for the D1, which is available on-line. Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 6, 2021 Author Share Posted July 6, 2021 Oh wow, thank you... Where is this manual mate, ive got the the one workshop manual, but no electrocil hence using haynes manual. Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 7, 2021 Author Share Posted July 7, 2021 Found the manual, easy enough to find which is quote surprising. So puzzled now it appears the MFU is bringing in the relay as i can feel it switching. But why, unsure why as i see one side of the coil is 12v permenant supply other side is via a NPN & MFU. So whats putting this on initially? Lots to think about, weekend job to get head round it. Quote Link to comment Share on other sites More sharing options...
Maverik Posted July 7, 2021 Share Posted July 7, 2021 There is quite a bit documented regarding MFU failure, this could be a symptom of, if be tempted to get that pulled and have a look inside it. I repaired a couple of them amd swapped them quite a lot to cure a multitude of problems. Quote Link to comment Share on other sites More sharing options...
teabag Posted July 9, 2021 Share Posted July 9, 2021 On 7/7/2021 at 4:42 AM, Jim Mason said: Found the manual, easy enough to find which is quote surprising. So puzzled now it appears the MFU is bringing in the relay as i can feel it switching. But why, unsure why as i see one side of the coil is 12v permenant supply other side is via a NPN & MFU. So whats putting this on initially? Lots to think about, weekend job to get head round it. The part the MFU plays is the intermittent wiper delay timing but only when that function is switched on. Plus theres few other things like the headlamp washer operation sequence and interior lighting delay. Quote Link to comment Share on other sites More sharing options...
teabag Posted July 9, 2021 Share Posted July 9, 2021 There a diagnostic test that’s available to check the items that it’s associated with. Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 10, 2021 Author Share Posted July 10, 2021 Just checking a few things... 12.3V onto 85 1.2v on 86 12.3v on 87 11.8v on 30 when relay switches. So relay coil is always engergised Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 10, 2021 Author Share Posted July 10, 2021 Getting no response out of the MFU when i try & perform the diagnistic test. Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 10, 2021 Author Share Posted July 10, 2021 What is the normal faults with them? Is this the MFU, some say its on the back of the fuse box... Quote Link to comment Share on other sites More sharing options...
teabag Posted July 10, 2021 Share Posted July 10, 2021 Any faults will identify as the one or more of the items shown in the diagnostic list that isn’t functioning. Also maybe the red illumination around the ignition switch isn’t there. The mfu is at the rear of the fuse board, two fiddly screws, iirc, to remove the board then unplug a lead or two and turn the board to reveal the mfu, there’s enough slack in the loom to do that, then remove the lead from the mfu and pull it to unplug. It was way back in 2011 when I had to replace my faulty mfu. Quote Link to comment Share on other sites More sharing options...
teabag Posted July 10, 2021 Share Posted July 10, 2021 12 hours ago, Jim Mason said: Getting no response out of the MFU when i try & perform the diagnistic test. Following the procedure it should go straight into the diagnostic function, very strange when things start working on their own. Quote Link to comment Share on other sites More sharing options...
Maverik Posted July 11, 2021 Share Posted July 11, 2021 MFU's where prone to having "dry" soldered joints, as well as susceptible to moisture which corrodes the boards. I successfully repaired one MFU by going over the joints with a soldering iron, became a small past time picking them up at landy shows at one point before I found one that all the functions still worked! A bit hit or miss, but I didn't have time to spend going through the whole board trying to find the problems. Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 11, 2021 Author Share Posted July 11, 2021 (edited) Trying to find one at a suitable price is the challenge, most want between £60 & £70. Think i might have found one for £20, but will only know when it arrives. £60 for a second hand one in an unkown condition is toi much of a gamble for me. So the image i shared is the correct unit. Edited July 11, 2021 by Jim Mason Quote Link to comment Share on other sites More sharing options...
SPendrey Posted July 11, 2021 Share Posted July 11, 2021 That's not the part you're looking for (in my best Alec Guinness impression). The MFU is more of a "black box" (or beige), but what I mean is it is a closed unit with nothing visible but the connector for a cable. It is mounted on the back of the fuse tray, so you might get lucky! https://www.ebay.co.uk/itm/264993894023?epid=649406371&hash=item3db2ddee87:g:rKIAAOSwcJhf61k9 Quote Link to comment Share on other sites More sharing options...
teabag Posted July 11, 2021 Share Posted July 11, 2021 Some pictures of the MFU I posted in this thread a few years ago. https://www.landyzone.co.uk/land-rover/multi-function-unit.64509/ Quote Link to comment Share on other sites More sharing options...
Maverik Posted July 11, 2021 Share Posted July 11, 2021 Here's somthing I posted about mfu's a few years ago. Quote Link to comment Share on other sites More sharing options...
Maverik Posted July 11, 2021 Share Posted July 11, 2021 Mfu - https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fp%2F649406371 The off white box it unclips from the main fuse board. Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 12, 2021 Author Share Posted July 12, 2021 Ouch lot of money to take on a gamble it works fine, could be even worse than what i already have How can i find a suitable work round to this problem... Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 14, 2021 Author Share Posted July 14, 2021 Purchased the Ebay one, the item i ordered the other day arrived this morning minus the back section... So got a spare fuse box lol... Just hope this resolves my issues and not adds to them Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted July 16, 2021 Author Share Posted July 16, 2021 Interesting, relay pulled... Still have access to wipee & wash functions. Just no park function. Could not go away with wipers on all the time... Quote Link to comment Share on other sites More sharing options...
Jim Mason Posted September 18, 2021 Author Share Posted September 18, 2021 Found the issue... Finding the time was the issue... Terminals corroded away, replaced with good second hand unit after a good clean... 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.