Crazy fuel gauge & dash board bulb replacement help plea

Need technical Q/A then you're in the right place

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Staty
My cat is called Dave
Posts: 568
Joined: Sat Mar 12, 2005 11:00 pm

Post Thu Feb 09, 2012 12:32 pm

Afternoon all, got a couple of bits on my car that have been winding me up recently, the fuel gauge is one of them, it's mental, never shows the correct reading, just flickers about here and there, is there any way of resetting it? Also i have a few bulbs out in my speedo, where the flipp can i get replacement bulbs from? Any help would be great as always, cheers guys :D
Grrrmachine
E30 Zone Wiki / Team Member
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Post Thu Feb 09, 2012 12:43 pm

Pretty much everything you need is in the Wiki. Click around this page:

http://www.e30zone.net/e30zonewiki/inde ... nstruments
Staty
My cat is called Dave
Posts: 568
Joined: Sat Mar 12, 2005 11:00 pm

Post Thu Feb 09, 2012 12:46 pm

Cheers bud :D
Staty
My cat is called Dave
Posts: 568
Joined: Sat Mar 12, 2005 11:00 pm

Post Thu Feb 09, 2012 1:02 pm

Not really got the information i need here, so any help would be appreciated, like where you can purchase speedo bulbs from and also how to access the fuel sender to see if it's that causing the problem, cheers
Grrrmachine
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Post Thu Feb 09, 2012 1:29 pm

Without the model of your car, I can't give specific info. But the sender(s) are in the fuel tank, which is under your back seat. You'll have one in the pump, and possibly a second one on the other side; both are under inspection hatches that you unscrew.

The wire inside them breaks, and grounds out all over the place, giving dodgy readings.

As for the bulbs:

http://www.e30zone.net/e30zonewiki/inde ... nstruments

available at any motor factors, for pennies.
Staty
My cat is called Dave
Posts: 568
Joined: Sat Mar 12, 2005 11:00 pm

Post Thu Feb 09, 2012 1:38 pm

Sweet as a nut bud, thanks for your help, i'll get on the case with them wires, is it a case of a bit of soldering? As i'll have the back seats out soon as i've got a replacement being re cleaned as we speak, cheers bud :D
Grrrmachine
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Post Thu Feb 09, 2012 1:41 pm

Unfortunately for the senders, you can't repair them; they use resistive wire of a special grade, so you need proper knowledge and equipment to fix them. If the internal wire is broken, you'll need a new sender.
Speedtouch
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Post Thu Feb 09, 2012 1:44 pm

You can remove the sender and use a multimeter to check that its resistance varies linearly as you move the float up and down.

If not, a new sender will most likely be required.
///M aurice
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
viewtopic.php?f=6&t=279421
Staty
My cat is called Dave
Posts: 568
Joined: Sat Mar 12, 2005 11:00 pm

Post Thu Feb 09, 2012 2:22 pm

Is it easy for any old mug "huuuut hmmm, me" just to take the sender out and replace it with a new one?
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Brianmoooore
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Post Thu Feb 09, 2012 2:25 pm

You check for a faulty level sender by pulling the plugs off of them, one at a time, and shorting together the relevant pins in the plug, with less than half a tank of fuel on board.
When you short the faulty one, the gauge will give an inaccurate but steady reading. Conversely, when you short the good one you will get an inaccurate and still jumpy reading.
If the gauge is still jumping around with both senders shorted out, then the gauge (nut on the back?) or wiring (unlikely) is at fault.
Staty
My cat is called Dave
Posts: 568
Joined: Sat Mar 12, 2005 11:00 pm

Post Thu Feb 09, 2012 3:01 pm

Right ok, i'm on it! Cheers bud