TH350C orange test connector use?

[Scaryfastatx]

Hi all

I'm trying to get my lockup working on my TH350C to squeeze every bit of mpg out of the old Scottsdale

I want to know what kind of behavior I should be seeing on the orange connector:

- 12v when the clutch should be engaging?
- 12v only when the clutch is engaged?

Thanks?

[bd]

For what year model truck are you seeking an answer?

For a 1983 C10 with MV4 (350C) transmission, the orange test connector is used to monitor and verify when 12-volt accessory power is supplied to the transmission TCC circuit through the service brake [applied] switch and low engine vacuum (i.e., high engine load) switch.  There is also a minimum road speed limit switch inside the transmission.  All of the described switches are connected in series with the TCC solenoid.  See diagram.

[Scaryfastatx]

For what year model truck are you seeking an answer?

For a 1983 C10 with MV4 (350C) transmission, the orange test connector is used to monitor and verify when 12-volt accessory power is supplied to the transmission TCC circuit through the service brake [applied] switch and low engine vacuum (i.e., high engine load) switch.  There is also a minimum road speed limit switch inside the transmission.  All of the described switches are connected in series with the TCC solenoid.  See diagram.

Thanks for the reply, it's an 81, I think I have everything hooked up correctly according to your diagram

Only difference I see is my 12v supply to the brake switch is pink

My truck had cruise control originally, if that changes anything

I didn't check the brake switch for continuity, will check that next

But was wanting to put a light on the test port to see when I should be engaging the lockup

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[bd]

Are you attempting to control TCC engagement manually or just monitor the OEM engagement protocol?

[Scaryfastatx]

Just monitor the OEM engagement

I'm hoping that I can get it working for the TH350 so when I go to a 700R4 it's working nicely