LS Swap 5.3 4I60e in 04 Jeep LJ.
- Thread starter mdbs14
- Start date
You lost me here. I have the starter purple wire linked to the T40 wire out of C104, the truck does start. My ls harness doesn't have any other wire for starter beside that purple wire on the starter.
Not doing it right?
Installed the winters shifter today, not a bad shifter. Am able to shift through all the gears.
When the truck is running, gear in neutral, I hear a grinding noise if If try to shift in Park. The TCC is not yet installed, could that be the reason??
When the truck is running, gear in neutral, I hear a grinding noise if If try to shift in Park. The TCC is not yet installed, could that be the reason??
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Is the drivetrain all hooked up to the axles? If there are no driveshafts, or your Tcase is in Neutral, or some other way the drivetrain can spin freely, it will do so as you shift through gears. Then when you try to go to Park, it has to stop spinning before the Park pawl can engage.
Ahh!! Yeah No, both of the drive shafts are dictonnected. Thanks.
I will connect the front drive shaft and put it in 4x4 and test.
With the TCC relay hooked up, should I be getting 12v whn key on, and no voltage when brake is pressed?? I have it connected and that's what's am getting.
Thanks
UNSTUCK
But stuck more often.
You can also just shut the engine off while keeping the transmission in gear. Once off, shift to park. Don’t try going from forward to reverse though, or visa versa.
Do you have the schematic for the brake switch from your swap vehicle? It will show when the transmission wants and doesn’t want a brake switch signal.
Do you have the schematic for the brake switch from your swap vehicle? It will show when the transmission wants and doesn’t want a brake switch signal.
This is how I have the TCC relay hooked up.
when testing, the ls tcc purple wire has 12v on key on, and drop when brake is pressed.
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UNSTUCK
But stuck more often.
Do you have the schematic for how the GM circuit works? You need to duplicate that circuit while tying it into the brake switch. We can’t tell you if you did it right without knowing what your particular GM circuit calls for.
I will say, looking at your picture more, the relay will not switch. C3:24 is an input. Not an output. You need an 12v output to energize the coil to switch the relay.
I will say, looking at your picture more, the relay will not switch. C3:24 is an input. Not an output. You need an 12v output to energize the coil to switch the relay.
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I will search for the Gm circuit diagram for 04 Silverado.
With the relay setup with the C3:24 wire, I get 12v on relay pin 30 when key is on, and drop when brake is pressed. I can hear the relay click, and voltage drop every time I press the brake. The relay is definitely switching.
I can move it to the L50 WH/TN wire if I have to.
I found the gm circuit below.
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UNSTUCK
But stuck more often.
Your GM pcm wants to see 12v at C1:33 when you step on the pedal and 0v when you’re off the pedal. Some of the cars were opposite of this, which is why guys would run a relay off the brake switch. You do not need to run the relay. Simply run a wire from pin 6 on the jeep brake switch to C1:33.
As for your relay switching right now, well, it doesn’t seem to follow what the schematic shows, so who knows. Either way it’s working opposite how you want it.
As for your relay switching right now, well, it doesn’t seem to follow what the schematic shows, so who knows. Either way it’s working opposite how you want it.
Where did you get that from? Pin C1:33 wants to see 12v all the time when the key is on, 0v when brake is pressed. No ???
Open circuit when Brake is Applied
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Looked at this again, and made some adjustment.
Relay pin 85 to pin 6 on Brake lamp switch
Relay pin 86 to ground
Relay pin 87 to ground
Relay pin 87A to 12v key hot
Relay pin 30 to LS TCC wire.
This will give 12v on key on, 0v brake pressed
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You need 12v on key on, 0v when brake is pressed down. here is another clear image.
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UNSTUCK
But stuck more often.
Your schematic shows a normally closed switch that is open in the drawing which represents the brake being depressed. It’s noted as such.
The truck schematic I posted shows a normally open switch, that would then close when the pedal is depressed.
The corvette drawing I posted more closely represents what yours shows, which says you’re doing it right if you’re using a car transmission.
Do you know for a fact that your drawing represents the drivetrain you’re using? My source for drawings (alldata) has not let me down yet.
The truck schematic I posted shows a normally open switch, that would then close when the pedal is depressed.
The corvette drawing I posted more closely represents what yours shows, which says you’re doing it right if you’re using a car transmission.
Do you know for a fact that your drawing represents the drivetrain you’re using? My source for drawings (alldata) has not let me down yet.
Interesting!! Though all gen 3 LS were wired that way with a closed switch that opens whn brake applies.
Does it matter if it's a 4wd vs a 2wd?
After digging more into this, I see why you believe that gm want to see 12v when brake pressed, 0v off brake. You are getting that from your diagram which is not giving you the full picture. Your gm wiring is showing just the brake Lamp switch which is indeed in the open position, but that has nothing to do with the TCC Positive Circuit.
what i am finding is that gm uses 2 switches built into the 1 switch. 1 is normally open, this is used for brake lights and the other is normally closed which is used for TCC and cruise control.
The TCC wire needs to see constant 12v on key on, and 0v when brake is pressed. Pressing the brake kills power to the TCC solenoid so that the torque converter doesn't fight the brakes. That's just how it works, at least based on my findings.
UNSTUCK
But stuck more often.
Looking at the brake schematic Alldata appears to contradict itself. Or maybe they are showing this schematic in the opposite of it normal position (which GM does on occasion) and they did not note it.
You can't have pins C and D both used in a normally open and a normally closed switch. This makes sense according to this diagram as it show only one switch that controls the TCC and the brake input.
You can't have pins C and D both used in a normally open and a normally closed switch. This makes sense according to this diagram as it show only one switch that controls the TCC and the brake input.