F41eatsFords

OK, this is kind of long, but I want to be specific. I have an 84 sport coupe, 305 vin H (NOT HO engine). It's shifting into OD, but no TC lock up. I have noticed that It will work in the rain, but it hasn't rained much lately while i've been driving, so no way of telling if that's still the case. I disconnected the tcc harness on the drivers side and sqeezed some dielectric grease in it and reconnected it. My theory being that the moisture from the rain closed the circuit. The only thing i've noticed is that the transmission isn't running as hot. still no lockup. here's a list of things i've elimintated, but correct my if i'm wrong.

1. the cruise control works as it should, so i figure it's safe to assume the brake switch is good. (purple wire leads to both CC and TC harness, right?)

2. I checked for voltage out of the harness, but I may have done this wrong, so please tell me.

F41eatsFords

sorry, i hit the wrong keys.

anyways, here's how I tested the harness. all I have is a test light, but I'm guessing it should still light up (it did when i bridged the batt terminals with it). I turned the key to the "run" positionin the ignition (didn't start the car, though, was i supposed to?), plugged one end of the tester into the ground on the harness (black/tan wire) and the other to the power (purple wire) and it didn't light. I also tried with the ground end to the frame, and the test light didn't light up. can someone tell me if This should have worked?

I also tried jumping the a and f terminals with a couple pieces of wire and a toggle switch to manually lock it up when up to speed, and it didn't work. when stopped at a light, i turned it on to see if it would even bog the car down, and nothing happened.

Here's some things i want to verify as well:

a) there should be continuous power from the purple wire with ingition in "run" position, with foot off the brake
b) green wire goes to ECM and ECM grounds it to lock up converter
c) tan/black wire is a ground (but for what?, since green grounds the TC control)

if the purple wire should be continuousm can I run a wire with a fuse and switch from the battery to the harness and drive it and test it that way, or would this be unwise?

I think i might take it to a trans shop sometime this week and have them figure it out, but if I can figure it out myself and save my time and money, i'd rather do that. It's been bugging me non-stop, and I have a long trip coming up at the end of june, so i want my gas mileage at its best (i can get 18 CITY when the TC lock up). it's only been giving me trouble for the past couple of months.

BTW, the car is stock, except for no air pump or catalytic converter, and it has an open air cleaner, and an external trans cooler before the factory one. yes, TC still locked even with the ext trans cooler.Thanks for any help you can give me!

80schild

iTrader: (5)

I'm interested in hearing answers to your questions as well. I've been trying to figure out why mine won't lock for a whole year now.

F41eatsFords

OK, so I found a wiring diagram on the mitchel website (thanks to my old HS shop teacher, and i think I figured out what my problem is; bad brake-pedal switch (the one with the vacuum line).

Here's how I tested it.

took my test light and grounded one end. the connector has 2 wires; pink w/ black stripe (power supply) and purple, which goes to TCC connector. with ignition in the "run" position, I tested for current from the pink wire; power there. then, I checed the purple, after power goes through switch, and no power. jiggled the switch and I got power (this would explain why it worked intermitently). to verify, I jumped the switch connector with a paperclip to guaruntee a connection. then, I used my wire and toggle switch in the ECM connector between the a and f terminals. took it for a test run and had TCC lockup.

I'll hopefully replace the switch tomorrow, and hope that will be it.

80schild, I don't know if it's that simple for you, but it's a way to eliminate a possibility if you haven't tested it yet.

80schild

iTrader: (5)

Theres two switches down there, one controls the brake lights, and the other controls the cruise and tcc. I replaced the one for my cruise/tcc and it still didn't fix it. I guess it wouldn't hurt to test it anyways though, I could have bought a bad one.

I have also replaced my tcc solenoid and soldered on a new connector. It's aggravating for sure.

Fast355

iTrader: (2)

Is this a CCC Q-Jet setup or an Export car with a Vacuum TCC Setup?

If it is a CCC Q-Jet setup, I am thinking you can ground the TCC through the ALDL connector which should eliminate the ECM control and lock the TCC if the rest of the system is working as designed.

F41eatsFords

I didn't replace my tcc brake switch (55+ bucks), but if you look at the bottom of the switch, there's a cover that can snap open. inside, there are 2 "plates" or "tabs" which touch each other. when the brake pedal is applied, it pushes a "wedge" between them and disconnects the circuit. really quite simple for that kind of change. I took a pair of pliers and bent the tabs so they make a better contact. haven't had any problems since. 80schild, you may even have to do this with your new switch; it looks pretty flimsy for the price you pay. if you're getting continuous power from the purple wire on the harness, though, it's not in that circuit. also, have your pressure switches or temperature switch been replaced? idk much about how everything works, so that's as far as I can tell you for the possible problem.