Land Rover Repair: landrover discovery 2 td5 2001, water ingress, light fuse


Question
QUESTION: the dash board light fuse keeps blowing. the radio & rear wiper dont work but everything else is ok. can you help please.

ANSWER: Hi Mac,

I would suspect that you may have a problem with the fusebox itself. What are the conditions of fuses #16 to #18?  I have heard that water ingress can damage the fusebox (corrosion?) and the repair is to replace the fusebox.  You'll have to investigate to see if water is causing the problem before you elect to swap out the fusebox.

Have you notice a pattern:  radio turned on THEN fuses blow; rear wiper activated then fuses blow, that sort of pattern? Have you opened up the dashboard indicators panel to see if there is a wiring problem with the lights?

Check www.discoweb.org for more possible causes and fixes to this problem.

Best of luck,
JohnMc

---------- FOLLOW-UP ----------

QUESTION: the fuses are ok. the radio comes on but needs a code.the wiper i suspect is ceased.you can hear the relay click but the wiper does not move nor is there any sound from the motor.the drivers side door mat is damp but not excessively. the fuse that blows is an 8amp one in a separate in line fuse holder. any ideas? i will check the fuse box though just in case.

ANSWER: Hi Mac,

You have a water ingress problem.   As for the components at fault, it could a problem with how the components share a connection.  See RAVE Electrical Library (section 4) to help with understand how the components operate via these connections.  

You'll have to chase down these faults individually.  Start with the rear wiper relay - if the relay is clicking, it is indicating that the relay is trying doing something it can't do.  You may have to replace the rear wiper motor.  Perhaps (reaching) this is triggering the 8A fuse to blow.

Where does the 8A fuse line run?  I'm not familiar with that.

Regards,
JohnMc



---------- FOLLOW-UP ----------

QUESTION: Wotcha John,
         sorry i have not got back to you before now, been chasing wires you know.Just so you know the 8amp fuse runs from the top right hand corner of the the top right multi plug on the passenger fuse board.Like you i can find no reference to it at all.I have replaced the wiper motor as it was seized & it works fine but the dash ligts didn't.
I then noticed the brake lights had stopped working?DOH!!!
I then studded the wiring diagram in depth & noticed that all the lighting runs like a house circuit,meaning that if you have a broken link all else fails connected to any part of that circuit.So i replaced the brake light switct,all ok,replaced the 8amp fuse in the holder & EUREKA!!! EVERYTHING WORKS.
Thanks for your help.
Regards.
Mac

Answer
Hi Mac,

Excellent!  Bravo!  Yes, it's true that if a taillight bulb blows it can impact other electrics.  We did not know that the bulb was blown so it only complicated the matter.  Did you notice if the bulbholder was corroded?  Water has a sneaky way of trickling into the bulb holders in the rear and corroding the contacts.  Yet another common problem.

The 8A fuse is intriguing.  I wonder who installed this and why?  I took a look (with the help of your description) and sure enough, my old Disco I has a very weird fuse wired up under the dash.  Someone soldered a 10A car fuse between a wire. I clipped it and the radio no longer worked.  I shrink wrapped the cut and the radio came back.  Why its there, I have no idea.  It's ugly but it seems to work.  A mystery that LR will keep to its grave, no doubt.  

I'm glad your back up and working.

Regards from this side of the 'pond',
JohnMc