th400 transmission not shifting

I have recently swapped out my tbi for edelbrock multi-port fuel injection on my 454 1 ton chevy. I removed my factory ecm computer to install edelbrocks computer. Well I have a th400 that wont shift automatically because that little orange wire that comes off of the tranny is just hangin there. I couldnt find a kickdown switch at all on my throttle on the tbi or on the gas pedal in the cab. I know theres a transmission relay on the firewall. According to mitchells wiring diagrams the little orange wire goes to the transmission relay then to the computer I no longer have. Is that correct and if so what can I possble do to get transmission to shift. Any help would be great because Im totally stumped.

Reply to
yblow
Loading thread data ...

What year THM400/3L80 is it?

----------------- TheSnoMan.com

Reply to
SnoMan

Its a 87 thm400.

Reply to
yblow

Its an 87 thm400 and correction to my post I dont have any forced downshifts.

Reply to
yblow

On Sun, 07 Oct 2007 11:57:58 -0700, yblow wrote in :

I may be mistaken but I believe your kickdown is mechanical.

Reply to
Frank Gilliland

Do you mean mechanical by a kickdown cable?

Reply to
yblow

There never was a cable on it before and it ran fine I just cant figure out were my orange wire goes from my th400 and if the factory computer has anything to do with my kickdown shifting. I cant find a kickdown switch anywere?

Reply to
yblow

On Sun, 07 Oct 2007 12:49:04 -0700, yblow wrote in :

My bad:

formatting link

Reply to
Frank Gilliland

The later TH400's had the detend controlled by:

The TPS, with an output from the ECM.

You'll need to get an aftermarket kickdown switch, from TCI, B&M or maybe Trans-Go.

Reply to
Refinish King

Read my earlier post.

There never was a cable on it before and it ran fine I just cant figure out were my orange wire goes from my th400 and if the factory computer has anything to do with my kickdown shifting. I cant find a kickdown switch anywere?

Reply to
Refinish King

I new it so the ecm took the signal from the tps sensor and than sent a signal threw a relay to the transmission. Hey thanks alot for the info just wanted to make sure brfore I spent 50 bucks on a kickdow switch.

Reply to
yblow

My pleasure:

Just remember, it will not only be a kickdown switch.. It will have some sort of module, and a relay to reduce the voltage to the 5 volt signal.(I think)

Good luck, and let me know if I can be of any help.

RK

Reply to
Refinish King

THM400 has long had electric kickdown. (I had a 68 that had it that way) In cars they used to put a slide switch on gas pedal arm under dash to would force kick down.The wire in question is likely the kick soleniod down wire.

----------------- TheSnoMan.com

Reply to
SnoMan

Hey thanks alot for your help Im looking into it today Ive still got the factory relay for the truck.

Reply to
yblow

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.