[tayto]

I'm on the final stage of rebuilding my 700-R4. My lockup wiring is very brittle, bending it about 90 degrees will cause the sheathing to break. I am wondering what type of wire is recommended for use inside the transmission. Is heatshrink OK to use in transmission oil?

Also I have a temp switch currently in my trans. From what I have read if the fluid gets above a certain temperature the switch will close and cause the torque converter to lockup in an attemp to cool the transmission down. Should I keep this in the circuit or is it OK to bypass? FWIW, TCC will be controlled via ECU.

 

[Crosley]

I would think a GXL or SXL wire would resist oil

Shrink tube needs to be polyolefin material. I use dual wall with adhesive inside it that flows out under heat.

Trans oil will soften up the budget shrink tube, been there.

or purchase a fresh replacement wire harness . Rostra is a quality brand harness

 

[tayto]

If I could get a new harness I would go that route as the plastic conduit is broken in many places. Any idea if they make a harness for a 1989 Caprice 5.7L? I have seen some delco ones but there is no information on what they are for and ythe pictures are crappy. I would need the one that has 4th gear switch going to the ecu with the temp switch. And then 2 wires for the lockup solenoid itself.

 

[SSedan64]

This one looks to have only the 4th gear & Temp connectors.
700R4 TCC Lockup Solenoid With Harness 700R4 Converter Lockup Solenoid

https://www.wittrans.com/Schematic.aspx?Transmission=700R4&Schematic=6

Local Trans Shop may also have the one you need.

 

[tayto]

Thanks SS, I found this one as well: AC Delco 24235642. According to the picture it looks like the correct harness.