Older Cars - No Speed Sensor
TS on 3/17/2005, 6:00 am, in reply to "TP 4773 and MBZ 300D Speed Sensor":
The speed sensor line in that car was to run the cruise and ABS systems.
Neither activate at a slow enough speed to be useful to the Trafficpro.
The Harman/Becker Parts dept has a Speed Sensor Adapter that installs
in line on the speedometer cable at the trans or speedometer head. Wire
it to power and ground and it generates the proper HALL Pulse based
on the spinning of that cable.
"Traffic pro installation in 1990 C2 Porsche"
Posted by JPS on 3/6/2006, 9:13 pm
I am trying to install aa Traffic Pro into this car and I do not have
a GAL wire. Is there another wire or way to get this done? Will the
Traffic Pro work without it?
Posted by alpina22 on 3/8/2006, 9:36 am, in reply to "Traffic
pro installation in 1990 C2 Porsche"
Your car has a speed signal
Easiest method is to locate the wire (red/white IIRC) from the HVAC
control panel. Use a DIN radio removal tool to pull the HVAC panel and
disconnect the two large connectors. This makes it easier to tap the
speed signal wire. To confirm you have located the correct wire, pull
the speedometer and find the red/white wire. Set your multi-metre to
Ohms. It should register a 1 Ohm load. However, if you probe the red/white
wire at speedo and HVAC at the same time, it'll ground the wire giving
you a zero load.
Did this on a MY91 C4 and it worked 100%.
The 964 belonged to a friend. He was very pleased with the TP. I've
installed them in several 993s and BMW M Coupes over the last year.
As for your dilemma, get to the speed wire at the back of your HVAC
panel. It's just a 10 minute process. Just get some 18-22 gauge wire
taps (red) from Radio Shack and attach a [same gauge] wire from the
speed signal wire to your TP, pin 1, socket A.