Some more BX help please!
  • Register
  • Help
Results 1 to 4 of 4
Like Tree1Likes
  • 1 Post By petermelb

Thread: Some more BX help please!

  1. #1
    Member Motorgnome's Avatar
    Join Date
    Dec 2015
    Location
    Gosford, NSW, Australia
    Posts
    64

    Default Some more BX help please!

    Hey guys.

    I'm needing some help regarding the dash/instruments on my BX19 TRI. When I got the car 18 months ago, it was only driven once, as many things were wrong with it. well after all this time fixing stuff, I am up to the dash & instruments. After working out why the dash illumination was out (all the globes were blown, including heater controls & cig lighter illumination) & also working out the illumination comes on with the ignition, not the parking lights, I am trying to fathom the various gauges & warning lights. Now, I have never owned a Citroen before, this BX being my first, but reading through the workshop manual & following various wiring diagrams I have worked a few things out regarding the warnings the dash provides, but I am still stuck on a couple of things.

    Firstly, the cylinder head has 3 temperature switches/senders in it. The lower one is for the temperature gauge & the upper two are for a warning light at the end of the red sector on the temperature gauge. The trouble is, I only have one wire to go to two switches on the head. I know it's not a big deal, as the temp gauge works accurately & either switch should illuminate the warning light, but I like things to be right..

    Secondly, the oil pressure & fuel gauges are all over the shop. The theory should be if I ground the oil pressure gauge sensor wire, it should read full (high) & if I take it off, it should read zero.. well it's a lucky dip..sometimes it reads high when its not connected & sometimes zero when it is connected. The same goes for the fuel gauge. The vehicle is stationary (on a hoist). Now both of these gauges have an electronic gizmo behind them that the instrument printed circuit board plugs into and I have no idea what it's for..Could this affect the operation of the gauges? the manual says nothing about it.

    Thirdly..I see that the oil pressure gauge also doubles up as an oil level gauge??? This is like some sort of witchery...Should I bother trying to fix it, or is this also affecting my oil pressure readings...Oh, I've got a headache ....

    Thanks for reading..I hope someone might enlighten me.

    Advertisement


    Cheers! Jason

  2. #2
    1000+ Posts Ken W's Avatar
    Join Date
    Sep 2002
    Location
    North Brisbane
    Posts
    1,465

    Default

    Hi Jason,

    This is reasonably well explained in the owners manual.

    Firstly the coolant temp gauge. The manual says if the warning light flashes on and off, slow down. If it remains on, stop immediately but let the engine idle for a few minutes. It also has a description for the coolant temperature light: Early warning: If it lights up check the coolant level. Warning: This also lights up the "STOP" warning. Stop immediately but let the engine idle for a few minutes. If the lamp remains on, stop the engine and check the coolant level taking precautions detailed on pages 38-40-42 and contact the nearest Citroen dealer.

    So it has a two stage lamp warning system. I can check the settings printed on the sensors if you want me to as I have one floating around in the shed. The oil temp gauge is a nice backup.

    Secondly, the fuel gauge should be pretty standard. The user manual says tank capacity 66 litres. Low fuel warning: 5 litres approximately. We have had problems with senders where cars have been left for years and fuel has gone off and varnished. Also if the tank has had a bang on the bottom, the pickup can be broken off and will not access the full tank of fuel.

    The oil level/pressure gauge has this story: Oil level gauge: The oil level will operate for approx 2 seconds after the ignition is switched on. The level is correct provided the needle is between the two red marks. The reading will be cancelled when the engine is running.
    Engine oil pressure: If it lights up while driving, stop the engine. Check the oil level. If the warning light remains on with correct oil level, go to the nearest Citroen dealer.

    In practice, I have always ignored the level gauge capability. Also on most older cars, the oil pressure sender has worn out so you get intermittant oil pressure readings. The low oil pressure light seems the most reliable bit so long as it is not leaking.

    Hope this helps.

    Cheers, Ken

  3. #3
    Member Motorgnome's Avatar
    Join Date
    Dec 2015
    Location
    Gosford, NSW, Australia
    Posts
    64

    Default

    [QUOTE=Ken W;1536049]Hi Jason,

    This is reasonably well explained in the owners manual.

    Firstly the coolant temp gauge. The manual says if the warning light flashes on and off, slow down. If it remains on, stop immediately but let the engine idle for a few minutes. It also has a description for the coolant temperature light: Early warning: If it lights up check the coolant level. Warning: This also lights up the "STOP" warning. Stop immediately but let the engine idle for a few minutes. If the lamp remains on, stop the engine and check the coolant level taking precautions detailed on pages 38-40-42 and contact the nearest Citroen dealer.

    So it has a two stage lamp warning system. I can check the settings printed on the sensors if you want me to as I have one floating around in the shed. The oil temp gauge is a nice backup.

    Secondly, the fuel gauge should be pretty standard. The user manual says tank capacity 66 litres. Low fuel warning: 5 litres approximately. We have had problems with senders where cars have been left for years and fuel has gone off and varnished. Also if the tank has had a bang on the bottom, the pickup can be broken off and will not access the full tank of fuel.

    The oil level/pressure gauge has this story: Oil level gauge: The oil level will operate for approx 2 seconds after the ignition is switched on. The level is correct provided the needle is between the two red marks. The reading will be cancelled when the engine is running.
    Engine oil pressure: If it lights up while driving, stop the engine. Check the oil level. If the warning light remains on with correct oil level, go to the nearest Citroen dealer.

    In practice, I have always ignored the level gauge capability. Also on most older cars, the oil pressure sender has worn out so you get intermittant oil pressure readings. The low oil pressure light seems the most reliable bit so long as it is not leaking.

    Hope this helps.

    Cheers, Ken[/QUOTE





    Thanks Ken.

    I don't have an owners manual...Yet..I just bought one on ebay (coming from the UK).
    From looking at the wiring diagram, It seems that any of the warning lights will also turn the STOP light on as well.. Clever system.

    In regards to the temp warning light, I only have two wires & three sensors/switches.. I have confirmed that one wire does the gauge, the other one does light, but I am unsure what to do in regards to the third sensor & no wire..Maybe it's broken further up in the harness. Not a big deal really.

    My main annoyance is this oil pressure/level gauge. I am wondering if the oil level part of the system is influencing the oil pressure part, as the the gauge can do anything at anytime, regardless if it connected to the sensor or not. At least the light works correctly (after a new oil light switch), so that is the main importance,

    The fuel gauge..It might be a dud tank sender like you say..The fuel system is clean , but these cars are old & the sender might simply be worn out. I will pluck it from the tank & have a look & play with it, whilst watching the gauge operation. Is this accessed from under the back seat?

    Thanks again for your help.. I now have a clear indication of how it all works..quite clever really..That is if it is reliable.

    Jason

  4. #4
    Fellow Frogger!
    Join Date
    Sep 2001
    Location
    melbourne
    Posts
    579

    Default

    If the oil gauge fluctuates when not connected it suggests a contact with an earth somewhere maybe in the loom or a bare wire rubbing against the body somewhere ?


    Sent from my iPhone using aussiefrogs
    Motorgnome likes this.

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
  •