BX electrical system - advice please

JohnW · Post by **JohnW** » 25 Jul 2004, 09:46

I'll try and keep this short! Newly purchased 1990 BX Tzi wagon in Australia is the subject. Car tidy and well maintained but some electrical "issues":
1. Central locking driven by remote "plip" device works only on left (passenger) side and tailgate, but there might be noises of relays from right (driver's) side too. Central locking spontaneously activates when driving sometimes, or when slamming driver's door.
None of lights work on "door open" panel. Interior lights work perfectly.
I plan to check for broken wires/mechanical linkages in driver's door as the first approach for this one, then the rear door on driver's (right) side. Other ideas welcome!
2. Oil pressure gauge and oil temperature gauge do not work. Some instrument panel backlight bulbs are dead and I'm also not sure which warning lights should be expected to be connected for this model. Fuel gauge only reaches 3/4 when car absolutely full of fuel.
Plan to remove instrument cluster, replace all bulbs and clean all plug and terminals. Other ideas welcome! For example, can someone tell me where the sending units (sensors) are for the malfunctioning oil gauges?
3. As a related matter, is the dashboard panel that includes the demisting vents a realistic item to replace, as mine is cracked in several places?
Many thanks if anyone can provide advice. I'm away for a couple of weeks tomorrow so may not acknowledge for a little while. But I will greatly appreciate any comments.
I've now discovered what a great car a 1.9 litre BX is too. Just a slow learner.....
JohnW

tomsheppard · Post by **tomsheppard** » 25 Jul 2004, 14:03

1. Door open panel. If none work then The common wire to earth or live, (Can't remember which)
2. Senders? oil temp in sump by drain plug.
3. Yes, allow yourself a day.

NiSk · Post by **NiSk** » 25 Jul 2004, 14:10

1) I'm afraid its a case of opening up each door in turn and checking out the wiring
2) you're already on it - and, this is a typical BX fuel guage problem - the float gets "waterlogged" with petrol and won't raise to it's highest position - either change it or learn to live with it!
3) if you can find one thats in better shape!
//NiSk

jeremy · Post by **jeremy** » 25 Jul 2004, 17:08

I had the fuel gauge problem, - the connector plug had came partially disconnected. I had to pull some more wire through to relieve the tension and everything has been fine for several years.
As you probably have the 2 tank arrangement don't expect it to read very accurately, especially when the suspension is down at the back and the tank is about 1/3 full.
Mine (TD) reads full for anything up to 150 miles!
The central locking and the door open lights use the same switches which are in the door locks rather than the interior light switches which are in the pillars. I found a generic door lock motor dropped straight in using the existing bolts and linkages without modification. The wires passing through the tubes into the doors can break.
Loads of information including the drivers handbook on Bob Smith's site.
http://www.rwbsmith.plus.com/citroen2/
jeremy

JohnW · Post by **JohnW** » 26 Jul 2004, 02:21

Many thanks for those replies.
I'll tackle it in a few weeks....
Cheers
JohnW

DLM · Post by **DLM** » 26 Jul 2004, 04:57

>2. Oil pressure gauge and oil temperature gauge do not work. Some >instrument panel backlight bulbs are dead and I'm also not sure >which warning lights should be expected to be connected for this >model.
I THINK the oil pressure gauge sender, viewed from the front of the car, is on the l/h side of the block near the oil filter and has a white centre section to it.
When replacing instrument panel bulbs, don't forget to remove the plastic cover over the back of the oil level/pressure gauge module. This gives you acccess to several more bulbs.
Warning lights? All of the centre display between speedo and rev counter, ABS to lower right of this strip. You MAY have a knock sensor warning light (the "K" light for some petrol-injection variants of the BX), dependent on the fuel injection system fitted.

JohnW · Post by **JohnW** » 31 Jul 2004, 12:14

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by DLM

>2. Oil pressure gauge and oil temperature gauge do not work. Some >instrument panel backlight bulbs are dead and I'm also not sure >which warning lights should be expected to be connected for this >model.
I THINK the oil pressure gauge sender, viewed from the front of the car, is on the l/h side of the block near the oil filter and has a white centre section to it.
When replacing instrument panel bulbs, don't forget to remove the plastic cover over the back of the oil level/pressure gauge module. This gives you acccess to several more bulbs.
Warning lights? All of the centre display between speedo and rev counter, ABS to lower right of this strip. You MAY have a knock sensor warning light (the "K" light for some petrol-injection variants of the BX), dependent on the fuel injection system fitted.
Many thanks for that extra advice. All welcome, believe me!
I'll get to it in a few weeks - a lot of away work this month or so.
Cheers
JohnW
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JohnW · Post by **JohnW** » 23 Dec 2004, 15:26

Quick message - still thanks to those who responded. I've been away so much haven't touched the BX yet. But I may get a chance over Xmas!
Best wishes to all for the festive season and the New Year.
JohnW

JohnW · Post by **JohnW** » 13 Feb 2005, 10:33

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JohnW

Quick message - still thanks to those who responded. I've been away so much haven't touched the BX yet. But I may get a chance over Xmas!
Best wishes to all for the festive season and the New Year.
JohnW
<hr height="1" noshade id="quote"></blockquote id="quote">
Finally into this. In the meantime the fuel gauge has been working properly - maybe a previous "lack of exercise" matter!
Door open indicator - some working now but have to check all bulbs before moving on. Plugged and unplugged multiplug to central locking controller behind handbrake and this happened.
Replaced oil temp sensor as the one in the sump was damaged. Made no difference!! Still to get further!
Fixed drivers side door central locking easily - broken plastic clip as far as I can tell. Rear right door C/L solenoid seems dead so that might be it now I've broken into the door. Most plastic clips went splat of course....
So we are making progress. Air ventilator fans fixed - resoldering the power transistor was all that was needed once I'd found my way into it.
Thanks again to advisors!!
Cheers
JohnW

JohnW · Post by **JohnW** » 15 Feb 2005, 18:17

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JohnW

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JohnW

Quick message - still thanks to those who responded. I've been away so much haven't touched the BX yet. But I may get a chance over Xmas!
Best wishes to all for the festive season and the New Year.
JohnW
<hr height="1" noshade id="quote"></blockquote id="quote">
Finally into this. In the meantime the fuel gauge has been working properly - maybe a previous "lack of exercise" matter!
Door open indicator - some working now but have to check all bulbs before moving on. Plugged and unplugged multiplug to central locking controller behind handbrake and this happened.
Replaced oil temp sensor as the one in the sump was damaged. Made no difference!! Still to get further!
Fixed drivers side door central locking easily - broken plastic clip as far as I can tell. Rear right door C/L solenoid seems dead so that might be it now I've broken into the door. Most plastic clips went splat of course....
So we are making progress. Air ventilator fans fixed - resoldering the power transistor was all that was needed once I'd found my way into it.
Thanks again to advisors!!
Cheers
JohnW
<hr height="1" noshade id="quote"></blockquote id="quote">
Well, we're down to only two issues - two gauges not working on the BX TZi - oil pressure and oil temperature. Replaced temp. sensor as it was obvious damaged and this made no difference.
I see no alternative to pulling out the instrument panel and checking earths and continuity to sensors from wires at back of gauges.
Any other ideas - that is, am I missing something?
Thanks
JohnW

AndersDK · Post by **AndersDK** » 15 Feb 2005, 20:01

Hi John -
Oil pressure switch & gauge sender unit is located on front of engine - near the starter motor.
If it's the red oil pressure lamp - the lamp should lit with sender cable earthed.
Both of the 2 gauges should read high if the sender cable is earthed.

JohnW · Post by **JohnW** » 17 Feb 2005, 14:36

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by AndersDK

Hi John -
Oil pressure switch & gauge sender unit is located on front of engine - near the starter motor.
If it's the red oil pressure lamp - the lamp should lit with sender cable earthed.
Both of the 2 gauges should read high if the sender cable is earthed.
<hr height="1" noshade id="quote"></blockquote id="quote">
Many thanks Anders - I watch your many pieces of advice with admiration! Sender cable is the one that is earthed through the "sender" is it not? I haven't been brave enough to do a direct earth in case I burned out the gauge but I presume you are saying this is OK?
Kind regards
JohnW

JohnW · Post by **JohnW** » 17 Feb 2005, 14:38

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by NiSk

1) I'm afraid its a case of opening up each door in turn and checking out the wiring
2) you're already on it - and, this is a typical BX fuel guage problem - the float gets "waterlogged" with petrol and won't raise to it's highest position - either change it or learn to live with it!
3) if you can find one thats in better shape!
//NiSk
<hr height="1" noshade id="quote"></blockquote id="quote">
Re fuel gauge - what it really needed was several tanksful of fuel to run it through its range. Now it works well!! Of course it stays "full" for nearly 150 km.... but at least it is working through the full range.
JohnW

AndersDK · Post by **AndersDK** » 17 Feb 2005, 19:36

The sender units are designed to actuate gauges and lamps when the sender is earthed or gets less ohmic resistance (narrows a shortcircuit) to earth.
If you're concerned by the gauges - you can short the wire through a car DIY testlamp - the needle tipped type with a crocodile clamp.

JohnW · Post by **JohnW** » 18 Feb 2005, 00:16

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by AndersDK

The sender units are designed to actuate gauges and lamps when the sender is earthed or gets less ohmic resistance (narrows a shortcircuit) to earth.
If you're concerned by the gauges - you can short the wire through a car DIY testlamp - the needle tipped type with a crocodile clamp.
<hr height="1" noshade id="quote"></blockquote id="quote">
Thanks Anders, that's exactly what I'll do. Pity about the difficult access to the oil pressure sender!!
Cheers
JohnW