fitting a rev counter heeeelp

[james9999]

hi all hope a all is well.ok i've got a fiat scudo 2005 diesel van.and i want to fit an after market rev counter .ive looked everywhere but no one will give me any answers,do i wire up to the alternator or ecu or what any help from someone would be great and how to fit it etc

 

[varesecrazy]

Obd port?

 

[portland_bill]

Some alternators have an extra terminal to feed a rev counter, but the rev counter would need calibrating to it, as pulley size variations will change the output.

Finding one that plugs into the OBD port would be a better option.