Speed sensor - Q4

[Alfan]

I have another speed sensor from a Thema 8.32 (should be the same part). However, the wires have been cut and I can't really see how to get to the connection in the unit itself, see photos. Any good ideas? Also I would like to measure if it is ok, does anyone have any info on this unit?

Hmm, I still get this message

Sorry, the board attachment quota has been reached.

Anyone who can help???

[wilco]

didn't i post a picture of it a while ago ? lemme see if i can find some

[wilco]

what i can find now

[Alfan]

Thanks. I wanted to post a photo of the one I got, as the wires are cut almost at the sensor. But the one photo shows that the top can actually be taken off (the plastic inside the metal casing)? And what should I measure if it is working?

[wilco]

Thanks. I wanted to post a photo of the one I got, as the wires are cut almost at the sensor. But the one photo shows that the top can actually be taken off (the plastic inside the metal casing)? And what should I measure if it is working?

not shure what breaks. i just replaced it..

[Alfan]

Ok, I will have to give it a try, as it is useless as is. Thanks for all the photos!

By the way, why did you replace it? Did the speedo all of a sudden just stop working?

[wilco]

mine worked randomly. so all or nothing.
if it's dancing, then it might be the little plastic gearwheel (or whatever its called lol)

[Alfan]

It just died and didn't come back in mine, that was why I was curious. I hope it's not the gearwheel...

[wilco]

did you measure the wires?
take the old one of and hook it to a drill.. if its that gearwheel, with a drill you should see something on the speedometer.
Also fast shortcut the 2 connections in the connector will move the speedometer.
Then you are sure that the error is not in the car itself.

[Alfan]

I tried another instrument pod with no change, so I'm assuming it's the sender - or the gearwheel.

But it will be worth testing the sender before doing more. Replacing the gearwheel does not sound like a simple thing...

[wilco]

replacing is actualy not really worse then the sensor itself. i was lucky i had the sensor replaced with a used one the first time so it was not stuck.
I had to shorten a wrench to get to it.
use a lot of wd40 before you start

[wilco]

Made this when i was searching..
might help you
http://www.cashhit.eu/alfa/Q4/Speedsignal164Q4.pdf

[Alfan]

Great info, thanks!

[Alfan]

I replaced the speed sensor, but that didn't help. I have bought the plastic/nylon wheel and metal part for holding it in place and when looking at my extra transmission, I can see that there is a screw on the side of the sensor hole and by loosening that it should be possible to pull out both the sensor and wheel as one assembly. I haven't done that yet on the transmission in the car, but that will be the next step. Hopefully, that will bring speed and distance back...

I have put some pictures of this in my photobook.

[wilco]

pull off the connector to the sensor. on the car side, fast shortcut the 2 wires.
The speedometer should popup a little. if not, it's a car sided problem.

[Alfan]

Now I got the speedo running again, so time for an update

I replaced the sensor, but that didn't help, so today I replaced the nylon wheel that the sensor goes into. Some of the teeth had broken off.But with the mileage, I guess that's ok. You can see a photo of it here

http://www.alfabb.com/bb/forums/164-168 ... or-q4.html" onclick="window.open(this.href);return false;

So now the mileage is being added again

By the way, there is a screw on the side of the gearbox, if that is loosened, it is possible to lift the sensor and wheel out of the gearbox, instead of having to get a wrench in where there is no space.

[wilco]

nice.
i know about the screw, bad part is, the wheel can fall into the gearcase and then you're kinda screwed
But in your case, you had to take it of

[wilco]

Now I got the speedo running again, so time for an update

I replaced the sensor, but that didn't help, so today I replaced the nylon wheel that the sensor goes into. Some of the teeth had broken off.But with the mileage, I guess that's ok. You can see a photo of it here

http://www.alfabb.com/bb/forums/164-168 ... or-q4.html" onclick="window.open(this.href);return false;

So now the mileage is being added again

By the way, there is a screw on the side of the gearbox, if that is loosened, it is possible to lift the sensor and wheel out of the gearbox, instead of having to get a wrench in where there is no space.

[Alfan]

nice.
i know about the screw, bad part is, the wheel can fall into the gearcase and then you're kinda screwed
But in your case, you had to take it of

I tried on the extra gearbox first and it couldn't fall into the gearbox unless it was broken. I put a photo in the alfabb thread.