TCC and cruise help
 

I was wondering how you guys verified that your TCC was hooked up and operating correctly? My truck is an 87 V10 with 5.3/4L60E. The brake switch on my vehicle has two side posts and two rear posts. When I apply the brake pedal it allows the plunger to come out on the front of the brake switch. The rear of my brake switch had two grey wires going to it. One had power with ignition on so i left that, the other post is where i hooked up the tcc wire. I thought about cutting the TCC wire and driving the truck, but figure Id ask here first.

My next question is regarding cruise. My truck had factory cruise. When i looked underneath the dash i found wires coming from my turn signal/cruise lever that had a pink wire going to ignition, a green wire, a blue wire, and a grey wire. The postings on here i found stated i was looking for a yellow, green, red, and blue. Can you guys confirm the wire colors, and tell me where you hooked into those wires at? Also, those are spliced into the pins on the bigger TAC connection correct (16 pins i believe)?

Hope this all makes sense, Thanks in advance.

Re: TCC and cruise help
 

What year is your engine/trans?

Re: TCC and cruise help
 

I'm going to assume its a GenIII since you have a TAC module. Any way, the way you can check to see if the TCC is working is to drive it, and when you're going above around 45mph at a steady cruise, just lightly step on the brake pedal. Only step on it enough to make the brake lights come on, but not so hard as to actually apply the brakes. You should feel the torque converter unlock, and the engine rpm's will jump up a bit, if you have a tach, you will see it.

As for the cruise, you need to find the wires that went to your original cruise module under the hood. In that plug you will find the same color wires you found under the dash. I would do a continuity test between the wires at the cruise switch plug inside, and the module plug under hood to verify you have the correct wires. The gray wire is "on/off" and goes to the TAC harness pin 14, the dark blue is "set/coast" and goes to pin 4, and the green wire goes to pin 5 "resume/accel". The last wire on the TAC is light blue and is in pin 6, you need to run this wire to the brake light switch, and hook it up to the brake light wiring side of the switch that is hot when the brakes are applied, I believe it will be a white wire. I "think" you will have to run that last wire because the older wasn't wired that way, but not totally sure since I've never had this new of a truck.

Re: TCC and cruise help
 

You are correct, Gen III. I do not have a tachometer but will try what you suggested. I am not sure what the cruise module on my truck looks like, I was just taking a stab that those were the wires, only other think it could be was wipers, correct?

Re: TCC and cruise help
 

Your cruise module will be the box under the hood with throttle cables going to and from it. Should be easy to find.

If for some reason its not there, thats fine, as the DBW trucks don't require a module, just the inputs from the stalk and the pedal. Technically, you can do DBW cruise with just a couple of momentary switches.

Re: TCC and cruise help
 

No cruise module, just looking for a way to verify the wires coming from my cruise stalk....read some stuff on here that said i was looking for red, green, yellow and blue...i found some red, blue, grey, wires coming from stalk. If those are not cruise i dunno what they could be. Thanks

Re: TCC and cruise help
 

Did you read this? Those 4 wires are the cruise wires. You can cut the wires under the dash and run new wires all the way to the TAC, but if you still have the wiring going to the original cruise module, they will be there. I don't know where you read that they were supposed to be red, green, yellow and blue, as they are not, unless you break open the cruise lever, inside they are those colors, but that's irrelevant

Re: TCC and cruise help
 

Thanks for clarifying. Thought I read about the red/green/blue/yellow under FAQ, cruise section, thats why the different colors threw me off. Ill get it wired up and test it out, Thanks again.

Re: TCC and cruise help
 

lsnova71,

I drove the truck this morning to test the TCC, and did not notice the torque converter unlocking or a change in rpms (no tach). Is there a chance I just wouldn't notice the torque converter unlocking? Is there a way to test the switch using a tester? Thanks!

Re: TCC and cruise help
 

On a stock converter and tune, the lockup is usually 45-47mph. Its possible that its so soft your not really noticing it, but there should be a 3-400rpm drop. IMO it usually feels like this on accel.
1,2,3,4...5 if that makes any sense

The way my truck is setup, o/d feels like a full fifth gear when it enganges.

Re: TCC and cruise help
 

A lot of times the lock up is so smooth you womt notice it, but unlocking you will. You could test the switch with a test light, the rear terminals should have power with the key on on both terminals, but loose power on one when the pedal is pushed. Did you get the cruise hooked up? That will tell you if the brake switch is working also, but I would assume it does.

Re: TCC and cruise help
 

To the OP the wires you hooked your TCC to are for cruise, the wires on the other side of the switch are for TCC. The grey wires are connected to the cruise harness. You need to verify operation before just hooking stuff up, be careful! Not a dangerous mistake, but not good practice. Good luck!