My mechanical speedo has finally broken, and it was reading around 15-20% high anyhow, so I have just got hold of an electronic speedo sender to fit
to my type 9 box.
There are 3 wires on it:
Black
Brown
Blue/Red
So I am guessing +Ve, -Ve and signal?
My question is, does that sound right and what type of speedo can I use? At present I have a 50mm mechanical type and would like to keep the same
size/style if possible. Also, money IS an object so nothing bling guys please 
The markings on the unit are: 'GM 30 or 90 (not sure) 185 189 12V 16IMP AK'
I am assuming the 16 means 16-pulse?
Any help much appreciated guys 
My speedo - Smiths 80mm, not locost - has 3 separate inputs wires that can be used which satisfy most
sorts of trigger signals.
Defined as :- Speed Signal input (Hall ECU), Low Voltage and a pull up/ pull down (if Required)
What you need to do is check yours out.
Power it up and spin it slowly. With a voltmeter, see if you get a 12v pulse between the
signal wire and ground / 12v or a resistance change to ground / 12v.
If you manage to get a signal, you can then count how many pulses you get per revolution
and that will help calibrate your speedo.
I use a Sierra, electronic pickup which is used for the ECU control and not normally a speedo
and that give 5 pulses per 2 output shaft revolutions. (ie, 2.5 pulses per rotation).
Hope this helps.
I am sure more info will turn up to assist.
An pictures of your sender?
Here is a picture of my Ford unit which fits in the gearbox at the rear of the normal cable drive.
Speedo_sensor_1
Speedo_sensor_2
Homemade retainer bracket.
The unit is one of these:
Description
where from???
Guess! - the Bay of course
Bump!
Hi folks,
I do not want to open a new case so i would like to use this one, i hope the author do not mind.
I have a problem connecting the sender with the speedo. I have this sender
Speedometer sender sending unit, magnetic pickup | eBay
and i have this speedo
New Speedometer, 3-3/8"'/86mm, LED light, Chrome bezel | eBay
The current setup of the sender is as follows:
I made the speedo connection as in the manual, and it is working, but it seems that i do not get any signal from the sender. I am doing the wires as
in the instructions for the sender, but i do not get any signal. I made a small mistake and connect the speedo signal cable to the tacho wire and it
works. So where is the mistake with the sender installation - 2 wires, brown - ground, blue - signal. the magnet is very strong, tried with another
one to decrease the gap - same sh-t.
Help please.
Thanks.
Yavor
If it helps that a Vauxhall/GM transducer (speedo sender) from an Astra GTE digital dash.
I used a sensor off aFWD escort box mated to one of them threaded adapters from Burtons..
quote:
Originally posted by Daddylonglegs
The unit is one of these:
Description