Help me transmission guru’s

[TURBOPOWERED68]

Help me transmission guru’s
How do I wire a non BRF tranny to a turbo Buick?
My Trans wire harness has 4 wires
And my Trans only has 3 wires.
What goes where?
Thanks
David.

 

[chris718]

the extra wire is the 3rd gear signal to the ecm.it looses ground after a 2/3 upshift is completed and tells the computer the trans is operating in third gear.the case connectors for the 3 and 4 wire systems are different and must be used with the proper harness.the trans will run without this but will not lock in 3rd and can affect engine performance if the ecm relies on 3rd gear signal for "tuning".if you need either the case connector or wiring we can assist you.

 

[bison]

You may need to drill and tap the vb for the 3rd switch also. Not a big deal to do.