Speedo/Odometer/Tripometer Stopped Working

[mti88m3]

I just got my new cables and short shift installed from AB Motorsports and got a few great days of driving in. Then just yesterday afternoon, I was going down the road and the speedometer fell to zero, and the odometer and tripometer stopped turning over.

I saw that this could be related to the speedometer cable being unplugged from the transmission, but I haven't seen a decent pic or diagram of where that's located. Could that also be causing my lack of odometer/tripometer?

[Dave Eds]

text from Wikilec if it helps


The Speedo gear, which must be removed, is located at the rear of the differential housing and is accessed from above. Tracing the speedo cable down from the bulkhead helps locate it.

[mti88m3]

Thanks Dave, I'll trace it and see what I find. Does that one cable handle everything? (the speed, mileage, etc.)

[Specky]

Here's a pic fella,

This is the end that wears, it normally causes low speed bouncing of the needle not total failure though.

Check the back of the speedo it may have poped out.

Does that one cable handle everything? (the speed, mileage, etc.)

Yep.



TTFN

[rip]

Are you sure you've posted the right pic there, Dave? I can't see the speedo cable at all. I can see the selector box but that is around the other side of the gearbox.

To find the speedo cable, remove the pipe which channels air from the wing to the plenum, then release the coolant header tank so it is free to move (no need to disconnect it), then push this forward to give yourself some room.
With those out of the way, you can get to the back of the gearbox. You should see a large, stiff vertical cable which attaches quite low right around the back. Once you reach in to touch it, your hand will obstruct your view. This is the speedo cable. It should be held in place by a small plate which itself is held in place by a small screw.

[Specky]

Correct picture, you're using a naff browser....

Basically you're seeing only half the picture, most people are seeing the full gearbox, saying that I can only see half a gearbox with an iPhone.

Monty highlighted this issue a while back. IE8 and firefox work fine on my home PC.


You should reconise the foam and metal connector that's jammed next to the selector, that's the speedo end of the cable.



TTFN

[rip]

Correct picture, you're using a naff browser....

Basically you're seeing only half the picture, most people are seeing the full gearbox, saying that I can only see half a gearbox with an iPhone.

Hmmm, I'm using Firefox & it is not giving me the option to scroll to the RHS of the pic. I've tried zooming out & that works fine though.

You should recognise the foam and metal connector that's jammed next to the selector, that's the speedo end of the cable.

TTFN

Looks similar to, but larger than my old Vauxhall ones.
I've not taken my Elan panel out yet.

[Specky]

Sadly what you see is what you've got,

in your case there is no need to scroll right because that's the picture your browser thinks is embeded.

Someone more geeky could explain better me thinks...

TTFN

[mti88m3]

Thanks Specky! Just to clarify, we're talking about the red circled area, correct?

speedo-cable.jpg

[Specky]

Yep

TTFN

[maz_r]

Just to add more confusion; did the engine start to run rough when the speedo stopped working?

One of the signals which feeds into the ECM is a VSS which comes off the speedo in the binnacle. If the speedo has stopped working, this signal will no longer be present and the ECM will think the car is stationary, thus affecting the engine behaviour.

Just wondering....

[mti88m3]

Well the speedo cable isn't loose at either end. I guess next step is unhook it from the diff and see if it's broken. Is there a source in the US for speedo cables? (I saw someone mention http://www.davebean.com/)

Just to add more confusion; did the engine start to run rough when the speedo stopped working?

One of the signals which feeds into the ECM is a VSS which comes off the speedo in the binnacle. If the speedo has stopped working, this signal will no longer be present and the ECM will think the car is stationary, thus affecting the engine behaviour.

Just wondering....

Not that I noticed, I wasn't driving hard when it stopped, just cruising at 45mph and I was almost home. I saw that some experience fuel cut past 4,000 rpms, but I haven't revved that high since it stopped.

[Specky]

If the cable looks OK, then it most probably is.

Saying that, check the speedo drive gear in the gearbox, they are known to give up the ghost.

Undo the bolt and pull out the cable and drive and give them the once over.

Hope that helps.

TTFN

[mti88m3]

How do I get the cable unbolted? I've removed the small plate that secures it, and I start getting it backed out, however, when I have it backed out a couple turns, the cable binds, and all my work unscrewing it is undone. Is there any trick or a better way to get the speedo cable unbolted?

[mti88m3]

No helpful tips? I have two blistered fingertips from the cable working against me while trying to unscrew it from the diff.

[steve matthews]

Honestly, I don't remember unscrewing it.
See if it just pulls out.
Steve

[Specky]

The easiest way to remove the speedo cable from the gearbox is to remove it as an assembly this will include the drive.

Undo the 10mm nut, remove the locking plate.

use a dumpy flat blde screwdriver and wiggle the lower end of the speedo and drive out, you can do a spin check and give the gear a once over.

when it's out, check the o-ring for pinching.

you'll have to have "eyes on" the other end when you spin check.

Hope that helps fella

TTFN

[mti88m3]

I had to fiddle with it for a little while, but I finally got it out today! By the way it looked, I assumed it had to be unscrewed, but it just pulls out. And yep, the cable's broken.



Where can I get a replacement cable in the US? And what's the best way to get the other end out of the speedometer?

[Specky]

Don't know the answer to the first question, may be obtaining a new or used one from the UK could be an option.

To access the other end of the speedo cable remove the instrument panel top cover (binacle), locate the drive cable and squeaze the white platic lugs together and it'''ll just pull back and out.

TTFN

[GeoffSmith]

Wiki updated so Rip can see the pictures!