cabech984

iTrader: (11)

Do I need a P/N Switch in order to have lockup and overdrive?

What input does the PCM need for TCC lockup? 12v, 5v or ground???

I recently swapped a 4L60E in place of my TH400 in my LQ4 powered 1990 Firebird. I'm having troubles getting torque converter lockup and overdrive to work. I'm running a Speartech custom harness with 4L60E controls. It doesnt have wiring for the P/N switch but only the Speedo sensor and the main connector for the valve body and solenoids.

nuckifuts

iTrader: (7)

My mustang does not have a P/N switch and my lockup and overdrive work.

You do have to have power REMOVED to the PCM when you step on the brake. I used terminal 87a on a 5 terminal relay with the factory brake light switch triggering terminal 85.

cabech984

iTrader: (11)

cool. I definitely have the purple tcc wire from the car connecting straight to the tcc wiring in the custom harness. Looks like Ill have to do the relay. Now I just need a schematic or a description of what the relay needs.

rockytopper

The tcc needs 12v+ constant this locks the torque converter. When the brake is applied the 12v+ is switched off. They sale a brake switch that does this. the standard GM brake switch applies 12 volts when the brake is applied. You need a switch that will do both.

The park neutral switch also controls the idle you need it also.

TomM

iTrader: (57)

Exactly, try a brake light switch off any car with cruise control, I used a switch from a 85 Monte Carlo, has one normally open, one normally closed contact, hook the brake light to NC, and the TCC 12v signal to NO not installed yet, they will reverse themselves when you install the switch and adjust it up against the brake pedal lever.......works like a champ....

T,

cabech984

iTrader: (11)

I'll look into this stuff asap guys, thanks for the help

fptransport

ask for a brake switch for a 99 or 2000 camaro is around 6.00 at the zone...

cabech984

iTrader: (11)

I think I've just gotta wire up a relay and I think I'll be set. My car had a 700r4 and cruise control originally so I think mine is fine

MeanYellowZ

iTrader: (19)

your brake switch will work fine with no added relay. An original 700r4 car should have the correct switch with normally open (NO) and normally closed (NC) contacts. If you have the wire leading from it that is hot with key on and the power dies when the brake is pressed then you are good to go on that end.

What kind of shifter setup do you have that has no place to hook up the park/ neutral wire?

cabech984

iTrader: (11)

No, I have the factory shifter in the car, I meant the black box on the drivers side of the 4L60E

MeanYellowZ

iTrader: (19)

There is a good chance the factory shifter should have a wire/ plug/ contact that can be used to ground the park/ neutral wire when those gears are selected.