i have a1985 1ton chevy pickup. i put a 700r in. it works great but no overdrive. my question is Is there a certain rpm that it needs to shift into o/d? i did not hookup the wires that go to trannydoes it need 12v to lockup? the truck didnot have the wire to plug into the tranny.
It needs a outside source for 12 volts to lock up converter. The ECM normally supplies it. It is the only function on tranny that is computer controlled. The for gear themselves do not need external power source but converter lockup does. The best fix would be a computer for a LD truck to handle this but then you would need engine control that it monitors too.
----------------- TheSnoMan.com
I think you mean this
Nope. The ECM doesn't supply 12 volts to the TCC.
Or, a vacuum switch from an early 80s LD truck that came with a
700R4
Oh yes it does, it controlls a sold state relay (SCR) that switches power to converter lockup circuit via a 20 amp fuse.
----------------- TheSnoMan.com
This is possible for non TBI engines but vacum switch would control a relay too.
----------------- TheSnoMan.com
Sorry, the brake switch is not a SCR, a relay, a computer, the ECM or any other such.
Vacuum switch and brake switch since that truck didn't have a 700 in it before. He will need the terminals that break the connection to drop it out of lockup. The switch he has only does the brake lights. Switched 12 volts to a fuse(10 amp) goes through the vacuum switch and down to the brake light switch. Then into the transmission.
Easiest way is to just buy the kit for about 70 bucks. They include the wiring harness and parts so you don't have to track down the extras.
Guess again, I have a 89 and I traced the circuit 16 years ago and it is controlled by a signal from ECM. You need to get your ducks in a row. The ECM monitors a lot of thing an the brake switch may break circuit but it will not lockup on my burb without a signal from ECM.
----------------- TheSnoMan.com
You guess, I'll stick to the factory manuals and wiring diagrams.
Well go trace it again. 12 volts on the purple wire coming from the brake switch, the tan/black wire is pulled to ground by the ECM for lock up, the light blue wire from the ECM is pulled to ground when the 4th gear switch closes telling the ECM that the transmission is in 4th gear. Tracing wires doesn't mean shit if you don't understand what is doing what.
Indeed. The TCC is controlled by the ECM, but the ECM does NOT apply 12 volts to the TCC to accomplish lock up.
Ducks have nothing to do with it.
Has anyone ever sat you down and taught you how to read a wiring diagram? Yes, YOUR truck's TCC needs the ECM to engage, but the ECM pulls the circuit to ground, same as how the fuel injectors are controlled, same as how the ignition coil is controlled, same as how an air pump switching valve is controlled, it does not apply 12 volts to the TCC solenoid as you state.
Oh, FYI, you CAN get the TCC to lock up on your truck without a signal from ECM, all you need to do is ground terminal "F" in the ALDL. The fact that you didn't know this is proof that you have zero idea how the circuit works or what methods can be used to diagnose it.
Again, you send people on wild goose chases.
So will l as I have factory manuals that came with 89 new but mine is either altered in your mind or you do not know how to read yours. There is no relay on my 89 for OD either. It is a solidstate SCR type device that switchs power to it.
----------------- TheSnoMan.com
I read them just fine, proof is I've been fixing them for a living long before your 89 was built. But tell me, how did you get from; "I traced the circuit 16 years ago," to; "I have the factory manuals that came with 89 new?" Repair manuals didn't come with GM vehicles in 1989 or any other year, and your story change smells like pure bull shit.
Between this and your idiotic notions about how an electric fuel pump is wired, it's obvious that you couldn't explain how an underhood light works.
Who said anything about a relay? Why do you even bring it up?
Your factory manual show that SCR, does it?
Not longer than me likely. Been around 4x4's since about 1960. I guess my manual and burb was made in china because it is as I stated not as you think it should be. GIven your past posts though you have a ego problem so your responces are expected.
----------------- TheSnoMan.com
1954 Ha-ha!
Since when is a published wiring diagram 'as I think it should be?"
12 volts from the IGN/Gauge fuse, passes thru the closed brake switch on the purple wire to the TCC solenoid, comes out of the TCC solenoid on the Tan/Black wire which goes to pin A7 of the ECM where the ECM switches it to ground when TCC apply is commanded. Open your Chinese repair manual and read thru diagnostic chart C-8. the whole thing is explained there.The only person with an ego here is you Snojob, you repeatedly insist on posting bogus technical information under the guise that you've "been around something since blah-blah-blah", or that your daddy invented it.
Sno...man why argue...scan the schematic page you are refering to and post it on a site for all of us to look at..... Post the subject to "Mr Blue" as all of us will be holding our breath waiting.!
Hopefully, he'll post the part from the service manual that says;
The purpose of the TCC is to eliminate the power loss of torque converter stage when the vehicle is in "cruise" condition. This allows the use of an automatic transmission with the fuel economy of a manual transmission. Fused battery ignition power is applied to TCC solenoid through the TCC brake switch. The ECM will engage TCC by grounding circuit No. 422 to energize the TCC solenoid. Engagement of the torque converter clutch will be executed under the following conditions:
I know a verbatim quote from the repair manual hardly stands it's ground against the word of someone who "traced" the circuit 16 years ago, but there it is, like it or not.
A neighbor Changed the tranny on his 89 s-10 lost the overdrive..
Problem was He Damaged the Rubber O-r> i have a1985 1ton chevy pickup. i put a 700r in. it works great but no
Snoman....whats up?
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.