Hi all, thought I’d pass on some info that I’ve gleaned over the course of my own project that could be useful to a few people on here now or in the future.
A huge number of european cars and motorbikes (mainly French and Italian - seriously, it’s probably the majority of them) from probably the 70s or earlier right up to the early 2000s use a common cable driven speedo mechanism made by Veglia. We’re talking from scooters to Ferraris and everything in between. Sometimes the instrument cluster is badged Veglia, sometimes is badged Jaeger, sometimes it’s not badged at all. If you've got a Frenchie or Italian up to about 2000, odds on it has a Veglia speedo.
If you want to do a conversion on one of these cars with a gearbox from a later model or a different marque, that has no mechanical speedo drive or a different ratio or something, you’re stuffed unless you’re happy to change to a third party speedo or can get some clunky (but expensive) motor-in-a-box solution to drive the stock speedo. Well, it turns out there’s another (easier/better) way. A small subset of models/variants use one of a couple of different types of veglia electronic speedo which is basically the same mechanism (and therefore fits in your original instrument cluster and screws straight to the stock fascia) but can be run from a 12V square wave from e.g a gearbox mounted hall effect sensor or a suitably conditioned ABS sensor.
On the left is the basic cable driven speedo. These are EVERYWHERE.
In middle is a type that uses a built in brushed mabuchi motor and a little circuit board that goes with it (not pictured) to control the whole thing. I got this from a mk1 Fiat Punto but I have noticed on my ebay searches that the same type is used on things like various Ferraris and various Alfas.
On the right is the other type I’ve found, in my opinion this type is better, it’s silent and more accurate but possibly more difficult to fit, depending on how your instrument cluster is configured. I got this from a 1.1 mk1 Saxo but I’ve seen that they were also fitted to citroen XM, Berlingo, Fiat Coupe, Tempra, Vauxhall Corsa B amongst others.
Try to get one that matches the position of your existing trip reset stalk - bottom centre or bottom left. If you can’t find one then it’s potentially possible to swap the reset bit over from your original mechanism.
If you have a frequency generator to test the thing and determine the frequency required to make the needle go to e.g. 9, 12 and 3 o’clock before you pull the needle off then that may make your life easier later on
Then it’s basically just a case of attaching your original fascia to the new mechanism and carving chunks out of the back of your instrument cluster casing to allow your chosen type to drop in. Obviously this may well work for other makes of cluster but obviously veglia to veglia is closest to a straight fit.
A huge number of european cars and motorbikes (mainly French and Italian - seriously, it’s probably the majority of them) from probably the 70s or earlier right up to the early 2000s use a common cable driven speedo mechanism made by Veglia. We’re talking from scooters to Ferraris and everything in between. Sometimes the instrument cluster is badged Veglia, sometimes is badged Jaeger, sometimes it’s not badged at all. If you've got a Frenchie or Italian up to about 2000, odds on it has a Veglia speedo.
If you want to do a conversion on one of these cars with a gearbox from a later model or a different marque, that has no mechanical speedo drive or a different ratio or something, you’re stuffed unless you’re happy to change to a third party speedo or can get some clunky (but expensive) motor-in-a-box solution to drive the stock speedo. Well, it turns out there’s another (easier/better) way. A small subset of models/variants use one of a couple of different types of veglia electronic speedo which is basically the same mechanism (and therefore fits in your original instrument cluster and screws straight to the stock fascia) but can be run from a 12V square wave from e.g a gearbox mounted hall effect sensor or a suitably conditioned ABS sensor.
Here’s a couple of photos of the 3 different veglia types I’ve found:
On the left is the basic cable driven speedo. These are EVERYWHERE.
In middle is a type that uses a built in brushed mabuchi motor and a little circuit board that goes with it (not pictured) to control the whole thing. I got this from a mk1 Fiat Punto but I have noticed on my ebay searches that the same type is used on things like various Ferraris and various Alfas.
On the right is the other type I’ve found, in my opinion this type is better, it’s silent and more accurate but possibly more difficult to fit, depending on how your instrument cluster is configured. I got this from a 1.1 mk1 Saxo but I’ve seen that they were also fitted to citroen XM, Berlingo, Fiat Coupe, Tempra, Vauxhall Corsa B amongst others.
If you want one of these electronic types then you’re probably off to ebay. You really need to see the back of the cluster as not all variants of any particular model have an electronic speedo. Sometimes ones that do have an electronic speedo had a couple of different manufacturers. But basically if you see a round bit sticking out the back and the 3 equispaced screws like this Punto one, that’s the motor type veglia.
If there are 3 screws in a triangle (or in some cases 2 screws and a blanked off hole like this Saxo one) then it’s the solid state one.
If you have a frequency generator to test the thing and determine the frequency required to make the needle go to e.g. 9, 12 and 3 o’clock before you pull the needle off then that may make your life easier later on
Then it’s basically just a case of attaching your original fascia to the new mechanism and carving chunks out of the back of your instrument cluster casing to allow your chosen type to drop in. Obviously this may well work for other makes of cluster but obviously veglia to veglia is closest to a straight fit.
Each type fitted to a previously cable driven Renault 19 cluster:
OK, great, so how do you run one of these then? Well, if you’ve got a hall sensor in your gearbox then you’re partway there. But unless you’re seriously lucky, the velocity/pulse frequency relationship will probably be different. So you can just use a motorbike ‘speedo healer’ device to sort that right out.
Alternatively if you’ve got an unused ABS sensor then you can still use the speedo healer, but first you need to convert the signal the ABS sensor gives out (usually an AC sine wave) to a square wave. For that you can use a ‘VR conditioner’ which is a little circuit board most easily available as an add-on for speeduino. Pretty cheap on ebay.
Well, that’s about it, hope that helps someone - now, or months/years down the line.