Help With Spedo please

[Anthony Pllu 262]

OK so hoped in the FD the other day and got half way down the road and noticed my spedo had stoped working.

 

Iv played around alot and cant get anywere with it.

 

Not sure were im supposed to check the signal from.

 

Tried different clusters etc with no luck. 

 

i have not touched anything around the gear box so no idea

 

 

[VDO 124]

You need to test the speedo transducer (sender) that attaches to the speedo drive on the gearbox.

 

Sounds like that might be the problem.

 

Can you have a look at the three wires that run off the transducer and tell me whay colours they are and I can tell you how to test it.

 

But you'll have to remove the transducer from the box to (bench) test it.

 

Where are you located..?

[Anthony Pllu 262]

im just out of adelaide. 

 

ill have to jack the car up more to get to the back of the box and look. 

 

What do you make of the voltage moving when its going from N to D

[deankxf 20,288]

im just out of adelaide. 

 

ill have to jack the car up more to get to the back of the box and look. 

 

What do you make of the voltage moving when its going from N to D

possible linkage touching the wires on the transducer..

[Anthony Pllu 262]

so is the transducer the little thing on the back of the gearbox? 3 wires comming from it?

[hendrixhc 10,920]

On the transducer plug there are three pins . If you look at there arrangement like a T the 1 on the bottom is the earth. Top right is power in and top left is signal output. 

 

The power to the speedo transducer should be 8.2vdc which comes from the instrument cluster loom plug pin 2.

 

The transducer output signal comes back to the cluster via the same loom plug and goes in on pin 8.

 

Id be checking the output voltage at the gear box end first and then checking continuity of the wiring.

[hendrixhc 10,920]

so is the transducer the little thing on the back of the gearbox? 3 wires comming from it?

 

Yes

 

The transducer is held in with 1 bolt.

[Anthony Pllu 262]

so i should be able to just the mutli meter on the spedo thingy on the box and get 8ish volts with acc on? then follow the loom up check joins make sure the volt stays the same all the way to the cluster

[hendrixhc 10,920]

yeah that will tell you that the supply to the transducer is present.

 

It wont tell if the transducer is outputting a signal though.

 

You could assume that if the earth is intact and the supply voltage is present and the transducer drive gear is not broken and the transducer rotates freely the the electronic part of the transducer is shot.

 

The only other option is the cluster is rooted but i think you said you tested that already with another cluster.

 

If that all makes sense

[Anthony Pllu 262]

yeah tried 2 clusters and 1 board. all of them have that werid voltage that goes from .3 to 12v when in gear on the brakes

[tpak addict 1,909]

Thing is you are not looking for a voltage as such you are looking for an input signal. From memory this comes from the white wire... I would say the transducer has died or the cog itself has worn.

[VDO 124]

As I said previously, you need to remove the transducer to test it.

 

Otherwise you're just carrying out "tests" which are not actually relevant or definitive.

 

Remove it, tell me the wire colours and I'll tell you how to test it.

[Anthony Pllu 262]

ok spedo gear is out. think i may already know the issue as i did not have to unplug it. just fell out of the socket. but might aswell test it before she goes back in

 

here she is

 

 

[gerg 10,871]

Looks a bit crusty there mate, also I've had the little clip that holds the plugs together break off, meaning the plug can come apart very easily.

[Anthony Pllu 262]

yeah the plugs themself are very dry and could crack if i squezed them. also while waiting for a reply i got under just to check something

 

i have heard that this casting on the block might mean something

 

[Anthony Pllu 262]

god dam over sized photos 

[Anthony Pllu 262]

i poped the spedo thingy back in and plugged it in nice and tight just to see if that was the issue. but still no spedo so have taken it back out again to wait and see how to bench test it

[VDO 124]

Black - Ground

Purple - Positive feed

White - Pulse signal

 

Connect 12v positive to the purple.

Connect ground to the black.

 

Now connect a multimeter, red to the purple and the black together with the ground.

Set multimeter to DC Volts.

 

Very slowly turn the gear and note where you started as you will need to make ONE full rotation and count the pulses as they appear as short pulses of voltage on the multimeter.

 

Turn the gear VERY SLOWLY or you won't see the pulses.  It should pulse 8 times in one rotation.

 

Any less than 8 pulses or no pulses means the transducer is definitely faulty.

 

The transducer usually requires around 8 volts but it won't hurt to use 12v just for this test.

 

If you are getting the correct pulses during test, then your transducer is good and you will need to trace and check the wiring and ensure there's a current supply to the transducer.

[hendrixhc 10,920]

Some good info there VDO. Your a champion!

[Anthony Pllu 262]

thanks VDO, iv packed up for the night so ill get into it again tomorrow. 

[tpak addict 1,909]

If you have to get a replacement XD-E are different to XF onwards

[Anthony Pllu 262]

so tested the transducer and not happy with the results. it was giving 0.018 then 0.009 then 0.006 and then nothing for almost a full rotation i was doing it as slow and steady as i could but never have 8 pings over a full rotation. will find a new one

[Anthony Pllu 262]

not even sure were to look for one

[hendrixhc 10,920]

Ebay

 

http://www.ebay.com.au/itm/FORD-XD-XE-XF-SPEED-SENSOR-TRANSDUCER-WITH-RARE-PURPLE-18-TEETH-DRIVE-GEAR-/131381126854?pt=AU_Car_Parts_Accessories&hash=item1e96ece6c6

[VDO 124]

So how did you get on..?