TH400 wiring
Thread Starter
Intermediate
Joined: Nov 2006
Posts: 44
Likes: 0
From: Redding California
TH400 wiring
On a 71, 350 converted to automatic,(bought that way) No wiring is attached to the transmission. I installed a new engine harness that has connectors to the transmission. Is there a wiring harness for the transmission that connects to the engine harness and if so where can it be purchased. I have installed a new dash harness and rear harness as well, both from Letric Limited. Thank you
Racer
Joined: Jan 2006
Posts: 313
Likes: 3
From: North of Boston Ma
Not sure but look into this lectric limited # VIG7100A ENGINE HARNESS, all automatic transmission Note: Requires use of VIG7074TCS to complete wiring to T.C.S. switch located in passenger side cylinder head.
Drifting
Joined: Apr 2008
Posts: 1,565
Likes: 2
From: Sparta Mo.
A Th400 is a NON-lock up transmission. The solenoid in the valve body is for passing gear. As long as the kick down cable is hooked up, you don't need to hook up the wire on the trans. (should be just a single wire connector) I've built 100's of Th400's and never once hooked up that wire.
If you have more than one wire, you probably have a Th400C or a Th375C. If that's the case, throw it out and get a real Th400.
If you have more than one wire, you probably have a Th400C or a Th375C. If that's the case, throw it out and get a real Th400.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
A TH 400 has no kickdown "cable" it's an elecrtic solenoid inside the trans with a switch on either the carb or mounted inside on the upper end of the accelerator pedal arm.
A TH 350 has a cable, (no electrics) that does the kickdown/detent downshift thing.
If it's a 350C (lockup TC) then there will be an electric connector on the side of the case for the TCC, but all detent downshift is handled by the cable connected to the carb.
The TH 375 or TH 375C is a TH 400 in a 350 case.
There's a connector not too far from the firewall connector that has a tan and an orange wire- that's one that goes to the tranny. The orange wire is the one that goes to the trans connector from the switch under the dash.
A TH 350 has a cable, (no electrics) that does the kickdown/detent downshift thing.
If it's a 350C (lockup TC) then there will be an electric connector on the side of the case for the TCC, but all detent downshift is handled by the cable connected to the carb.
The TH 375 or TH 375C is a TH 400 in a 350 case.
There's a connector not too far from the firewall connector that has a tan and an orange wire- that's one that goes to the tranny. The orange wire is the one that goes to the trans connector from the switch under the dash.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
TH400 wiring is simple. Ignition switched power to the switch on the accelerator. Switch on accelerator at full throttle closes and applies 12v to the terminal on the side of the transmission.
Drifting
Joined: Apr 2008
Posts: 1,565
Likes: 2
From: Sparta Mo.
But a Th375 looks just like a 400, (same shape pan and all) it just has the Th350 tail shaft.
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