Wiring Harness Decision
Thread Starter
Instructor
Joined: Nov 2016
Posts: 145
Likes: 16
From: Santa Maria California
Wiring Harness Decision
I have a 74 auto that I'm converting to a Tremec 5 speed manual so I need some help on deciding what engine harness to get. I'm getting conflicting information. Some say to get a manual harness but others are saying that I should just use an automatic because there's something on the manual harness that tells the distributor to set the timing different when it gets shifted into 4th gear. I don't know the details as to why, how, or what but I need some experienced guys opinion. What would you do?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Unless you live in a state where nothing can be changed on the emissions system (like Cal-eh-forn--ee-a), you really don't want to maintain the TCS system, anyway. The only benefit of having it is to create somewhat less emissions at idle. Generally, it is detrimental to fuel mileage, engine life, idle quality, and idle temperatures.
Since you won't have a 'pristine' example of that model anymore (since going to the Tremec), just dump it.
Since you won't have a 'pristine' example of that model anymore (since going to the Tremec), just dump it.
Burning Brakes
Joined: Nov 2005
Posts: 1,137
Likes: 51
From: Cartersville GA
I had purchased my wiring harnesses for my '69 with auto, then decided to upgrade to the 5 spd Tremec. Wasn't much difference, I had to make a harness for the reverse lights switch to go from the Tremec to where it connected on the auto harness, that was about it. Most of the main harness appeared to be used for both auto and manual, if auto they just taped the unused connector (like the one for the clutch pedal safety switch) to the harness. Look at the wiring diagram for the two harnesses and you'll probably find there's not much difference.
Thread Starter
Instructor
Joined: Nov 2016
Posts: 145
Likes: 16
From: Santa Maria California
I had purchased my wiring harnesses for my '69 with auto, then decided to upgrade to the 5 spd Tremec. Wasn't much difference, I had to make a harness for the reverse lights switch to go from the Tremec to where it connected on the auto harness, that was about it. Most of the main harness appeared to be used for both auto and manual, if auto they just taped the unused connector (like the one for the clutch pedal safety switch) to the harness. Look at the wiring diagram for the two harnesses and you'll probably find there's not much difference.
