Touring Speedo Wires

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KDS
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Post Sat Oct 29, 2005 5:39 pm

Hey all,

So my speedo is still dead. I had my mechanic look into it and the speed sensor and connector are testing fine. Also, the (brown and red/brown) wires from the connector and up into the body are testing fine. By the time they reach the speedo, one of them is dead. So the problem must be a wiring failure somewhere as it passes through the passenger compartment.

Before we rip up the whole interior, can anyone tell me the route these wires take in a Touring? Under the rear seat? Along the side of the transmission tunnel? Along the sills?

Any help appreciated!



Posted: Thu Sep 22, 2005 10:59 pmԚ Ã”šÃ‚  Ԛ Post subject:
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First check the connector to the speed sensor on the rear diff, these corrode.

Also check the wiring from this connector, these also tend to break internally over time.
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-KDS in Vancouver ('88 325i Touring)
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Brianmoooore
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Post Sat Oct 29, 2005 11:32 pm

The speedo wire goes to a plug and socket under the right rear seat base, across the car, down the left cill, and aross behind the dash, BUT I still say the break is within two inches of the diff plug.
The break is internal to the wire, and can't be seen by looking at the individual wires. Can be found by pulling the wire and it will stretch.
Replace the section of wire completely with a piece of wire and yellow plug from a headlamp connector off a scrapper.
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KDS
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Post Sun Oct 30, 2005 4:38 am

Thanks, Brian. Will check it out.
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-KDS in Vancouver ('88 325i Touring)
oze30
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Post Sun Oct 30, 2005 10:59 am

if mine is intermitent, could it be the sensor not contacting the drive plate in the diff? if so, how can i fix it?
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Brianmoooore
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Post Sun Oct 30, 2005 1:58 pm

oze30 wrote:if mine is intermitent, could it be the sensor not contacting the drive plate in the diff? if so, how can i fix it?
Sensor doesn't contact anything inside the diff. It's a magnetic pickup.
It's possible for the internal winding in the sensor to fail, but that's rare.
Check the wire as above.