Does TCC switch work without computer?

[urbex]

Much of the factory original "unneeded" parts in my '86 was stripped by the clueless prior owner. When I say "unneeded", I mean the things like emissions bits that many people consider to be dead weight that hamper performance...yeah, thanks for sending the MPGs even further into the toilet by ditching the EGR, dipsh...

Anyways.. he also ditched the converter lockup vacuum switch, which I have procured another one. Is this a plug and play thing, or will I also need the original carb ECU to properly command lockup? I know I can make it work with just a toggle switch if I so chose, but I figure if I'm going to run an auto, I'd rather have it all auto, lol.

 

[b454rat]

Switched via vacuum, so could be either way. I'd guess it went thru ECM since everything is eventually computer controlled.....

 

[Blue85]

1986 was carb and would have had the vacuum switch. The ECM had nothing to do with lockup until TBI came in '87 (you know, until there WAS an ECM). California trucks did see the ECM/carb combo for a couple of years (the infamous CCC), but the transmission was the same as the 49-state truck and thus lockup was controlled by vacuum. I'm assuming this is not a CCC truck or the alterations would likely have it barely or not running.

There were many variations of 700R-4 wiring, but in general you need 2 wires to it. One is straight through the brake pedal switch and the other is through the brake pedal switch and the vacuum switch (your main lockup control). There is also a hydraulic component of deciding to lock/unlock, but that valvetrain likely remains in the transmission like it came from the factory. This vintage transmission also has an OUTPUT wire that was used to control a vacuum solenoid (mounted in the engine bay). The only thing I know it was used for was making EGR only work in higher gears/cruising. If you have no EGR, that wire won't matter.

Was the harness cut up or were things just unplugged? If you have the original harness, carb and intake manifold it should be plug and play to put all the pieces back.

 

[urbex]

I know some of the stuff back in the 80's came with a rudimentary computer hooked to the feedback carbs, my '87 Samurai did, all of my Fieros did, etc, just didn't know if the K5s got them. I also can't remember having had any other 80's vehicle with an automatic trans since the '85 S10 Blazer I had in high school.

There's been both parts removal AND wire/connector removal with what I can only assume was a pair of hedge clippers...or maybe his GF...I don't know. Some of it was reassembled with wire nuts...it's an overall nightmare. I have a whole new Painless harness sitting on the shelf that's going to end up in this truck eventually.

Factory motor bits were pulled, and replaced with a hacked up Edelbrock intake to fit the TBI heads...poorly, and Edelbrock carb. Thankfully, he left that as it came out of the box. I'd be a whole lot more concerned about that if I didn't have a 454 on the stand getting built. Yes, there's a 4L80 core on the floor behind it that will be getting built to handle the motor as well. The factory wiring for the TCC lockup switch is still on the firewall, though I'll have to splice in a new connector (which I got from the junkyard donor).

I just wanted to make sure that it will work as is, so that I'm not chasing my tail trying to chase down wiring gremlins that don't exist later, lol.