Speed Sensor for Aftermarket NAV system?

[97d90#773]

howdy folks-

wondering if anyone can help me with and install of a becker cascade audio system - - it has sat nav, however, it requires connection to the vehicle's speed sensor to function - - wish this wasnt the case and i could just disable on headunit, but this isnt an option - - soooooo, for this thing to work ive gotta tap into the speed sensor....

anyone have any ideas? the install manual can be found on www.becker.de go to service and you can view the pdf install manual for the becker cascade system

id be greatful if anyone can offer any help - - this kinda stuff is a little over my head - - thanks all - -

97d90#773

[Pat]

a) if you don't care about the NAV feature just ground the terminal 1 (GAL signal, --see page 13--) and that is going to simulate an always stopped car.
b) if you do care about the NAV feature then it's more complicated:
b.1) if you have a mechanical odometer forget about it.
b.2) if you have a digital odometer:
b.2.1) If the speed sensor has 2 terminals (inductive), forget about it.
b.2.2) if the speed sensor has 3 terminals then just replace the original circuit with the modified. Note 1: the diodes are low direct Voltage junction. Note 2: the new terminal "might" need a pull-up resistor.

Original
http://img60.imageshack.us/img60/952/speedowiring7ef.gif


Modified
http://img110.imageshack.us/img110/9281/speedowiringtappingspeedsignal.gif



...to the best of my knowledge...

Pat

[souza]

I think if you search under 'vdo' speedometer on this site you might find the info for which wires on the 97 D90 have the speed pulse signal. sounds like you simply have to tap into that wire and run to your NAV system? should be relatively straight forward I'd think. The wire should also be found behind your speedometer, as aren't the 97's electronic?