I have a 1988 Pontiac Fiero GT 2.8L 5spd, I am not getting any continuity into the car from the VSS sensor. I am checking this on the purple and yellow wires is this correct? Also, the wires come off of the VSS sensor, go through a plug connection, and go back into the trans housing, does anyone know where these wires come back out and into the harness at, so that I could check there, because I think it is either there or in the main harness, but I would rather prove continuity coming into the harness before I start pulling heat tape and chasing the harness. I have a Hanes manual, but it isn't showing my model connector, and the VSS sensor is brand new with the red gear and is set in place good. Any help would be greatly appreciated, because I don't want to drive the car without the speedo working.

From the connector at the VSS there is a continuous wire that runs to C203 located in the armrest below the ECM.

Here is the pinout for C203. - http://www.chalnet.net/Fier...0pinout/c203c500.pdf

From there a continuous wire runs to the dash connector.

Here is the pin out of the dash connectors.



Wires inside of the harness don't fail unless they are physically damaged or extremely overheated. 80% of damage occurs right at the connector. 10% is physical damage to the harness somewhere. 10% occurs when a wire is overheated to the point that it gets hot enough to cut into the insulation of a the other wires.

[This message has been edited by phonedawgz (edited 09-29-2013).]

Thank you very much, this will be very helpful, sorry so late to re-post, have been extremely busy with work and my lil one, do you know by any chance though where the wires come back into the harness from the transmission, because I don't see any wires coming out of the trans, which leads me to believe that they must go into the engine and come out on the engine somewhere, i'm getting continuity in the front harness but none at all coming into the car, I don't quite understand why the wires go back into the trans housing, and I would hate to pull the entire harness and then the problem be somewhere internal. Any help would be greatly appreciated.

The wires don't go back into the transmission or engine. The yellow and the purple wire start at the VSS directly via a 2 pin connector, then those wires run from the VSS into the large wire loom that goes through the firewall and into the clear plastic C203 connector under the armrest like Phonedawgz said. You are probably confusing the extra set of wires leading to the back-up light switch on the transmission with VSS wires. The back up light switch has a light green and a dark blue wire.

I'm a little curious how you are testing continuity on the yellow and purple wires. You must unplug the VSS and the speedo and then test each wire end to end (purple to purple, and yellow to yellow) to see if there are any breaks in either one. You'll need a jumper wire to help reach with your multimeter.