Does the OBC affect the operation of the Odometer?

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dffrntwn
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Does the OBC affect the operation of the Odometer?

Post by dffrntwn »

Doing some repairs on my '84 633csi and I temporarily unplugged my OBC, would this cause the Odometer to stop working in my gauge cluster? Speedometer works as normal too.
1984 633csi 5-speed, (1982 Honda CR250, 1982 Toyota Pickup, 1981 Lancia Zagato Spider, 1964 MG MGB Roadster).
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Brucey
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Re: Does the OBC affect the operation of the Odometer?

Post by Brucey »

I don't think so; the one signal goes into a single board and thence is used to drive the speedo and the odo.

The #1 thing that stops the odometer from working is that the gears fail.

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Da_Hose
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Re: Does the OBC affect the operation of the Odometer?

Post by Da_Hose »

I had some weirdness with my odometer not running after disconnecting the OBC. Checked all connections and it came back, so maybe there is a relationship in function there.

Jose
1987 M6 - My dream car
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dffrntwn
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Re: Does the OBC affect the operation of the Odometer?

Post by dffrntwn »

Da_Hose wrote: Sun Feb 18, 2018 5:45 pm I had some weirdness with my odometer not running after disconnecting the OBC. Checked all connections and it came back, so maybe there is a relationship in function there.

Jose
Hello Jose, so when you said checked all connections did you find something that wasn't connected properly?
1984 633csi 5-speed, (1982 Honda CR250, 1982 Toyota Pickup, 1981 Lancia Zagato Spider, 1964 MG MGB Roadster).
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dffrntwn
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Re: Does the OBC affect the operation of the Odometer?

Post by dffrntwn »

Brucey wrote: Sun Feb 18, 2018 8:57 am I don't think so; the one signal goes into a single board and thence is used to drive the speedo and the odo.

The #1 thing that stops the odometer from working is that the gears fail.

cheers
Seems my gears have failed, so good call. I've found two vendors selling reproduction gears. Who does the e24 community recommend?
1984 633csi 5-speed, (1982 Honda CR250, 1982 Toyota Pickup, 1981 Lancia Zagato Spider, 1964 MG MGB Roadster).
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Da_Hose
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Re: Does the OBC affect the operation of the Odometer?

Post by Da_Hose »

I am not sure what connector it was. I assumed it was gears, fiddled with connectors, ordered gears, and then it came back. Been working fine for years since.

Jose
1987 M6 - My dream car
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smtguy
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Re: Does the OBC affect the operation of the Odometer?

Post by smtguy »

One thing I have noticed - If your odometer is working on a BMW this old, don't push the trip reset button. I did and the odometer stopped working. I somehow got it to work again by pressing the trip reset while driving, and I have not touched it since. Why tempt fate!
1983 Bronzit 633CSi 5 speed
2004 Audi TT Quattro 6 speed

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Re: Does the OBC affect the operation of the Odometer?

Post by Hakeem43020 »

There's a connector behind the cluster that has something to do with the obc. I left mine disconnected by accident and the MPG and a few other things on the OBC didn't work. Not quite sure about the odometer since mine doesn't work but I guess it's possible.
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dffrntwn
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Re: Does the OBC affect the operation of the Odometer?

Post by dffrntwn »

Just a follow-up, I had a few teeth missing on my speedometer gears, replaced them and it's working again. So, in this case, the OBC wasn't the issue.
1984 633csi 5-speed, (1982 Honda CR250, 1982 Toyota Pickup, 1981 Lancia Zagato Spider, 1964 MG MGB Roadster).
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