Anyone know where the speed sensor on the 3 speed automatic is?

I also need a diagram or info on the part/neutral switch. I can't find it on the wiring diagram.

 

speedometer sender is mounted on the rear differential cover. Park neutral switch is on the trans where the shift cable attaches driverside .

 

Thanks Jim

I found it on the transmission, but I can't find anything in the wiring diagrams, ie. the wire colors, power source, which connector they use on the main board.

 

Rob,

On part I of the current flow diagrams for a 1980 it show three wires going to the "automatic gearbox". The first terminates at K1 and is gr/br, the second terminates at U6 and is also gr/br. These two points are tied together and have no other feeds. The final wire is the brown ground wire. I'm not sure this is too useful, in fact it is a bit strange. Look at page 97-53.

 

Marc,

Thanks. Yes I found that & you're right it is a bit strange.
What I'm trying to do is simply pick up a signal of the park/neutral circuit to tie into the ECM so the LT1 will know if its in neutral or not.
I'll probe K1 and U6 & see what it I get.

The signal from the 928 speed sensor I may be able to use for the ECM and scan tool I'm using. I mounted a speed sensor on the axel which works OK, but if the signal from the stock sensor works with the LT1 ECM it would make that unnecessary.