Speedometer Troubleshooting

[bball1137]

Here is what I got.

 

I have a 1990 C1500 that had a TBI 4.3 v6 and a th400 stock.

I swap the motor and tranny for a 5.7 motor and 700r4 transmisson out of a 1990 g10 van. The tbi 5.7 has been converted the 4bbl carb I vave removed the tbi and ecm. My problem is the speedometer no longer works. I have a few questions. First is should the vss in the 700r4 out of the van be compatible with the drac in the truck? If so does someone have a good troubleshooting guide for these electronic speedometers?

 

 

thank you,

[bball1137]

update found a ground wire that ran out through the firewall wall on the passenger side.For future reference when swapping to a carb and cutting out the ecm. There are three wires going through the passenger side firewall that you need to keep. 1- grey wire to the winshield wiper motor, 2, black with white strip to ground for speedometer, 3- heavy red wire to + side of bat or to power distrubution under cover on passenger side firewall.