Torque Convertor Lock-Up Switch

[BadBowtie]

I have a 1984 Chevrolet Silverado with an all stock 5.0L and TH350C transmission. With 2.73 gears right now I want to add a manual over-ride switch for the TCC lock-up.

Which wires are safe to tap into for this manual switch? Blue or green??
Or does it matter??

-Jon in TX.

 

[Ricko1966]

I have a 1984 Chevrolet Silverado with an all stock 5.0L and TH350C transmission. With 2.73 gears right now I want to add a manual over-ride switch for the TCC lock-up.

Which wires are safe to tap into for this manual switch? Blue or green??
Or does it matter??

-Jon in TX.

Do you still need to do this? Are you just trying to keep the converter from locking?

 

[BadBowtie]

I still need it. Trying to delay lock-up, until highway speeds.

 

[Ricko1966]

One wire at the transmission plug will be constant hot. Cut it splice in a toggle switch. I'm pretty sure that truck will have a vacuum switch on the firewall that completes ground to the tcc solenoid. Unplug that see if that keeps it from locking up. Not that familiar with the th350c. Anyway if that does stop lockup you could just intercept that wire,might make for a cleaner job.

 

[89GMCJimmy]

One of these would work
I had mine installed by trans shop when they rebuilt it

 

[BadBowtie]

One wire at the transmission plug will be constant hot. Cut it splice in a toggle switch. I'm pretty sure that truck will have a vacuum switch on the firewall that completes ground to the tcc solenoid. Unplug that see if that keeps it from locking up. Not that familiar with the th350c. Anyway if that does stop lockup you could just intercept that wire,might make for a cleaner job.

Yes, we have that vacuum switch on the drivers side firewall. I have that connector unplugged now (way I bought the truck too) and the lock-up is inactive today.
The 2.73 rear axle ratio is terrible for drivability on an all stock 305cid. With the harness plugged in on the firewall, lock-up occurs 95% of the time as soon as she goes into 3rd gear. Leaning towards 3.42 down the road.

So I can just cut the green or blue wire there and install a manual switch??

 

[Ricko1966]

Yes