speedometer: the petrol gauge and temp gauge not working

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Manni198
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Fri May 23, 2014 5:42 pm

hi guys as it says in the title my petrol gauge and temp gauge are not working!! my econometer occasionally works. does anyone know what could be causing this???
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Brianmoooore
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Fri May 23, 2014 6:47 pm

Are the SI lights working as they should?
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Manni198
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Sat May 24, 2014 1:17 pm

will check if si lights light up but one thing i can say is that when ignition is turned on i do not get oil lights or any other lights turning on with exception to the battery light. also i have noticed that my in car heater fan is not working. now if the fan switch is turned on and i start the car the fan works while engine is turning over as soon as i let go of the key once car has started the fan turns off again!!
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Brianmoooore
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Sat May 24, 2014 1:22 pm

Anyone been playing with the starter motor wiring?
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Manni198
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Sat May 24, 2014 5:03 pm

nope
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Manni198
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Sat May 24, 2014 5:04 pm

a friend has suggested it could be a regulator on the back of the clocks? the car is an everyday driver. and no si lights lighting up they used too!!!
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Brianmoooore
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Sat May 24, 2014 8:58 pm

Manni198 wrote:a friend has suggested it could be a regulator on the back of the clocks?
Your friend is mistaking an E30 for a bit of '80s BL or Ford scrap! Nothing as unsophisticated as that on an E30.
Your gauge problems probably revolve around failed SI board batteries. Take the board out of the cluster and measure the voltage across them.
Thye starter motor question was referring to your fan problem. How about the door mirrors? Do they work?
You haven't told us what model and age of E30 you have, and is the engine the one it left the factory with?
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Manni198
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Sat May 24, 2014 9:27 pm

ahh okay the shell is 320 and the lump is 325i its j reg which makes it a 92 i think. nope the mirrors have also stopped working i am beginning to think its the ignition switch behind the barrel?? also which board are we exactly talking about in regards to si lights? iv'e had a quick shuffle to try and get clocks out but am i right in saying the steering wheel and steering column cowling must come off to get clocks out?
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Brianmoooore
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Sat May 24, 2014 9:51 pm

Steering wheel and column shroud do not need to be removed to get the clocks out. The little panel under the clocks is removed first by reaching up from underneath, then the shroud is removed, the screws holding the cluster removed, the cluster pulled forwards and lain face down on the column shroud, the plugs removed, and the whole cluster slid out to the left.
Several screws hold the front and back halves of the cluster together, and the SI board lives in the front half. Pull out the coding plug on the front of the cluster, remove the single screw, and slide out the SI board. The bracket that holds the SI board in place also holds the 'check' symbol in, so don't lose that. I'm sure it's all in the wiki.
The mirror/heater problem is related to your starter motor wiring. Is the engine and loom pre facelift?
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Manni198
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Sun May 25, 2014 8:04 am

ill check si today also how do i tell if its pre facelift wiring?
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Brianmoooore
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Sun May 25, 2014 10:12 am

Manni198 wrote:ill check si today also how do i tell if its pre facelift wiring?
What colour wire, if any, is connected to pin 15 of each half of the C101 20 pin engine loom plug and socket.
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Manni198
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Sun May 25, 2014 12:31 pm

im getting 3v via the two battery's and are we talking about the ecu plug? also Brian can u possibly phone me as im using work computers today and not supposed to if u one ring me i can ring back wen i get to the phone in the car only because i have clocks out atm and need them back in by end of shift to get home your help so far is well appreciated
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Manni198
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Sun May 25, 2014 12:32 pm

ill check engine bay i think i know what your talking about is it the round connector?
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Sun May 25, 2014 2:52 pm

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Manni198
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Sun May 25, 2014 8:18 pm

yep the wire to pin 15 is green and black i have another set of clusters which also have the same problem so its not the clocks however i have not checked the batteries in the spare set.
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Brianmoooore
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Sun May 25, 2014 8:27 pm

Manni198 wrote:yep the wire to pin 15 is green and black
On both the plug and socket?
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Manni198
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Sun May 25, 2014 8:28 pm

could this possibly be an ignition switch fault???
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Brianmoooore
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Sun May 25, 2014 8:30 pm

Manni198 wrote:could this possibly be an ignition switch fault???
No.
Have you seen my last post?
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Manni198
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Mon May 26, 2014 8:03 am

shit will check today. as your a team member can you tell me why i cant get access via my phone to e30zone it keeps saying my login details are incorrect
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Manni198
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Mon May 26, 2014 2:36 pm

The wires in plug and socket is green and black
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Manni198
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Wed May 28, 2014 10:58 am

Mr moore u ther mate?
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Manni198
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Sun Jun 01, 2014 12:33 pm

does anyone else know what could possibly wrong with my car
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Brianmoooore
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Sun Jun 01, 2014 9:28 pm

What remaining faults do you have?
Are the batteries in your instrument cluster NiCd or Lithium? (NiCd batteries are exactly the same size as an ordinary AA battery, Lithium ones are much shorter.)
The green/black wire on the engine loom side of the C101 goes to the starter motor, and appears to be connected wrongly, or you have the wrong starter motor.
There is the black/green wire, a black/yellow wire, a large black wire from the battery, and a medium sized wire all going to the starter motor solenoid. Where are they all connected? The black/green and black/yellow are hidden under an outer sleeve, so you may have to push the sleeve back slightly at the end to see the colour.
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Manni198
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Mon Jun 02, 2014 8:09 pm

ok will check wires to starter tomorrow. the batteries are the shorter lithium type and are measuring 3v at terminals, is this the correct voltage? i assume it is as these batteries are normally 1.5v each. i didn't want to take them out unless needed as they have some epoxy like stuff to keep them held in place. should i be getting a 12v signal at the c101 plug engine side when starter has kicked done its job of turning the engine over?
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Brianmoooore
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Tue Jun 03, 2014 9:35 am

If you have a SI board with Lithium batteries, that changes everything, especially if they read 3 volts each. The Lithium battery boards have their own problems, but killing some of the gauges isn't usually one of them.
Open up the C101 again, identify the brown/white on pin 4, and connect this pin on the car body side to earth with a piece of wire. Turn the ignition on. The temp. gauge should go to full hot.
The green/black wire should be effectively earthed all of the time, except when the starter motor is operating, when it should be 12 volts+.
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Manni198
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Tue Jun 03, 2014 10:10 am

Will check this out
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Brianmoooore
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Tue Jun 03, 2014 1:37 pm

Do your reverse lights work? These are supplied by fuse 10, but this fuse also has an effect on several other things in the car, including the correct operation of the heater fan and the mirrors.
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Manni198
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Tue Jun 03, 2014 3:50 pm

no thats another thing thats all of a sudden stopped working ill be checking all this when i get home 5
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Brianmoooore
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Tue Jun 03, 2014 6:19 pm

If you don't give me the full picture, then I might not get the diagnostics right!
Fuse 10 is almost certainly blown then. A byproduct of this fuse blowing is that the the coil of relay K7 becomes backfed, with the end that should be at 12 volts+ being dragged down near to zero by other circuits from F10.
F10 also provides one of the feeds to the instrument cluster as well, so might even be related to your instrument problems as well.
The usual cause of fuse 10 blowing is the wiring to the switch on the gearbox. It goes down through the grommet at the base of the gearlever, and is clipped to the fixed part of the gear linkage. Either the insulation is rotted (usually by oil leaks) or it has come adrift from its clips and has been savaged by the rotating propshaft.
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Manni198
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Tue Jun 03, 2014 7:44 pm

thanks Brian for all help it was the No. 10 fuse!!! i may have overlooked it when checking the fuses. my bad
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Brianmoooore
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Tue Jun 03, 2014 9:45 pm

Has that cured all the issues?
If fuse 10 blows again, there is a plug and socket under your gear lever gaiter that can be pulled apart to disconnect the wiring to the reverse light switch under the car until you can attend to it. Wire colours are blue/white and green/white.
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Manni198
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Wed Jun 04, 2014 1:52 pm

i personally think its the heater blower inside the car that tripped blew the fuse as speed tree dont work and the fan needs replacing as it churping
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Brianmoooore
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Wed Jun 04, 2014 2:02 pm

A faulty heater fan will not blow fuse 10 under any circumstances! It will be the reverse light switch wiring.
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Manni198
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Thu Jun 05, 2014 4:51 pm

what normally or were does it go wrong? bad connection at a common point? i only say this because my fan seems to be squealing and not working at speed 3 out of the 4 fan speeds? I presume this is the switch
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Brianmoooore
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Thu Jun 05, 2014 10:38 pm

Never seen a faulty fan switch yet, but that doesn't mean it's impossible.
Fan is squealing because its motor is over twenty years old and has probably never been lubricated since it was made. It needs to be removed from the car (easy job - it comes out from the back of the engine bay) and oiled properly. Fairly sure the details are in the wiki.
If the fan still doesn't work on position three, it's more likely to be a problem with the resistor pack than the switch.
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