So where do i find all these 'bad earths' ?
  • Register
  • Help
Results 1 to 11 of 11
  1. #1
    Tadpole Naything's Avatar
    Join Date
    Oct 2005
    Location
    Gympie, QLD
    Posts
    22

    Icon5 So where do i find all these 'bad earths' ?

    Hi all,
    I've been having electrical issues with my 90 MI16 and while trawling the past threads hasn't provided any answers as yet, I have noticed that a lot of other faults have been put down to 'Bad Earths'. So i was just wondering where are the most common places that fault that i should look for? Where has worked for you and did it fix any unrelated problems?

    Advertisement

  2. #2
    1000+ Posts Gamma's Avatar
    Join Date
    Oct 2004
    Location
    Picton NSW
    Posts
    1,412

    Default Start at the battery

    Start at the battery.

    Check all the major junctions, (motor to body and body to battery). Anywhere there is a green wire with a yellow stripe - clean the terminal, (I assume that the wiring codes are the same or similar to the 505).

    Remember it is a 16yo car and there will be a certian ammount of corrosion in the works, (engine bay is a good start). The services of a good Autoelectrican might be in order.


    What are the major problems????
    /// 1986 SII 505 GTI
    2003 T5 307 HDI
    2013 LandRover90
    Sacred cows make the best hamburger mince.
    If you run, you only die tired

  3. #3
    Fellow Frogger! Meggsy's Avatar
    Join Date
    Aug 2004
    Location
    Brisbane
    Posts
    351

    Default

    As a good tip and to prevent further corrosion after you clean the eart points cover them in a couple of heavy coaus of nitrocellous lacqer... nail polish.

    It really works and seals the joint to moisture.

    cheers
    Meggsy
    Current - 4007HDi
    Had - 407 HDI 406 SV 404, 504, 505 GR and STI. 405 GR ( carbie version) STI, MI16
    And an Austin 1800
    Learnt to drive in 203 Convertible and a 403 SW

  4. #4
    Tadpole IBLOWN's Avatar
    Join Date
    Feb 2006
    Location
    Penrith, Sydney
    Posts
    25

    Default

    dunno if it helps, but my 405 has a bad earth. its one of the connections on the back of the fuse panel. its burnt. and its sent the whole of the electrics crazy!
    Peugeot 405 sri 94' everyday. Commodore once a month.

    http://www.cardomain.com/ride/2213367

  5. #5
    Tadpole Naything's Avatar
    Join Date
    Oct 2005
    Location
    Gympie, QLD
    Posts
    22

    Default

    Thanks i'll look at those tomorrow (today!). At the moment i have no internal fans, no a/c and no horn. I get power to the klaxon relay above the glovebox which i assume is for the horn but there is no power anywhere to be seen around the heater blower, air con switch or fan speed dial. So i'm assuming there is a relay somewhere that has gone open circuit, possibly because of a bad earth.

  6. #6
    Fellow Frogger! Pate's Avatar
    Join Date
    Dec 2004
    Location
    Finland
    Posts
    178

    Default

    Bad earths:

    Front lights, horns, fans (yellow connectors on bottom corners of fans)


    Under the battery rack, motor, battery etc. (yellow connector, again)


    Between rearlights, under plastic cover. Earth for rear lights

  7. #7
    Tadpole Naything's Avatar
    Join Date
    Oct 2005
    Location
    Gympie, QLD
    Posts
    22

    Default

    Pictures! Thats great thanks, now your speaking my language!

  8. #8
    Tadpole Naything's Avatar
    Join Date
    Oct 2005
    Location
    Gympie, QLD
    Posts
    22

    Default

    Quote Originally Posted by IBLOWN
    dunno if it helps, but my 405 has a bad earth. its one of the connections on the back of the fuse panel. its burnt. and its sent the whole of the electrics crazy!
    Thanks IBLOWN, after systematicaly checking all the other suggested locations, well except for the earths in front of the cooling fans ( I can see 'em, but i can't reach 'em), i checked behind the fuse board. The top corner is covered in a green residue and the back panel is starting to corrode! Is this the same problem you had? Anyone know how to get the fuse board apart to check it out?

  9. #9
    Fellow Frogger! Decca's Avatar
    Join Date
    Jul 2004
    Location
    Canberra
    Posts
    896

    Default

    the green residue is vertigris (spelling?) usually indicates a high resistance joint, and in phone lines will introduce noise.

    clean all surfaces with a file and/or wire brush, rejoin all connectors and sealing wouldnt hurt if its likely to cop a bit of moisture

    According to the Haynes manual, the earth that is part of the fan speed control and the blower is also used for the wiper motor and the heated rear window.
    If they are also affected then it could be the same earthing problem.

    The horn could be a different fault as the horn is usually earthed near the horn itself



    Decca
    Present --2016 2008 Outdoor / 2014 RAV4 Diesel (My utilitarian beast)

    Past -- 19?? 403 / 1974 504GL / 1972 R12TL / 1995 405SRi / 1997 406ST / 1998 306XT / 2004 406HD1 / 2008 308XSE HDi / 2008 307XSE

  10. #10
    Tadpole Naything's Avatar
    Join Date
    Oct 2005
    Location
    Gympie, QLD
    Posts
    22

    Default

    The green residue is from the back of the fuse board, the connectors on the front aren't showing any sign of it that i can see, it seems to be comming from one paticular spot, i could resolder that spot but thats about he extent of my skills when it comes to circuitboards. It's made up of 3 layers so i can't even see what is going on inside without taking it apart and it seems much to fragile for my clumsy fingers to try.

    The wipers are working i know that for sure, i haven't checked to see if power is getting to the rear window but it is definitely getting to the rear window heater switch. So maybe the earth is not my problem. I pulled out the blower motor and hooked it up to the battery and it goes fine. There is still no power to any of the connectors that plug into it nor to the actual a/c switch on the dash or the a/c ecu that lives under the dash. I've just printed out a copy of the haynes wiring diagrams for the 405 and will endevour to hunt down where the power goes missing tomorrow.

    The central locking is also no longer working and i am certain it was still going after the fans had stopped so i might have a few rabbit holes to fall down by the looks.

    I'll let you know what i find.

  11. #11
    Moderator Alan S's Avatar
    Join Date
    Mar 2001
    Location
    Queensland, Australia
    Posts
    8,923

    Default

    I'd suggest you start looking at multi plugs for internal corrosion. Grab a can of "Contact cleaner" from Dick Smith and give them a spray and wipe and then mechanically clean if necessary (sand, file etc). When you reconnect them, use a smear of silicone grease (vaseline at a pinch) around the plastic edges where they slide together to be sure they seat fully in and to assist in keeping moisture or dust out in the future. Look in stoopid places for these multi plugs, like under the battery or even under the battery carrier, under carpets and seats. To me it sounds like one is either covered in shyte, been accidentally pulled apart due to not being clipped together correctly or the wires to it have been broken or accidentally cut.
    In the BX, there are also earths connected to the steering column as well as one that can be seen from the drivers seat that sits alongside the passsengers front seat near the centre console.
    A clue on the green corrosion stuff is to dip the end into a cup with a bit of warm water and bi-carb of soda will wash the verdigrease off but be warned that often this stuff will grow up inside the insulation and cause problems where they can't be seen. If you grab a service sheet that shows the wiring diagram, look for an approximate location of where a bunch of wires meet and go looking there for the multi plug. It's my guess that this is where you'll find the problem.


    Alan S
    If it ain't broke, use a 12" shifter.....that usually does the trick!!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •