5.3/4L60E Harness Question????

[cl08]

I am wanting to put a 5.3 in a 64 C-10. I am wanting to do a 4L60E or 4L80E for a transmission. What exactly needs to happen for the transmission harness? Do I need an internal or external or both tranny harnesses? Do they need to be modified?

I do not have the 5.3 motor yet. The one I am getting is from a JY 100% complete (accessories, harness, ECM,etc.), BUT I am sure it will not have the transmission harness (at least I dont think it will). I am doing some swapping for a stock 4L60E/4L80E Trans. I am not sure if it will have all the wiring it needs either.

This my first attempt at late model electronics (350/400 bolted to a 700r4 is my knowledge) and I am very neverous trying late model electronics. I know its better and time to move out of the stone age.

I am trying to get everything sorted out before I start buying anything.
I am sorry if I seem very novice in my questions, I am just trying to get all my eggs into a basket. Any response would be greatly appreciated.

[70 Suburban]

what year is it?

[Clyde65]

My .02 is dont worry about the harness at all, just get an aftermarket new harness. It will be alot nicer and not have all the GM crap in there. I know there are alot of people doing the harness themselves too. If you look on EvilBay, search for Stand alone wiring harness, there is one there, also look on LS1Truck.com, very good info, also theileen I think is his handle has a great LS swap page here too. Lots of good info and people to help you.

I did the rework harness and now I wish I would have spent a little more on a new one, it works but isnt very attractive.

Clyde65

[tommys66]

Unless the JY cuts the transmission harness off of the motor harness, it will be connected with the motor harness. The PCM controls the transmission on these motor/transmission setups, therefore the trans harness is ran thru the motor harness. the only problem you might run into if you do not get a motor and transmission from the same year, is there are a few different speed sensors and Park neutral safety switches.

[vin63]

Sometimes it's easier to get a stand-alone transmission harness/control module that way you can just focus on the correct ECM for the engine type you end up getting. I'm running a CompuShift unit with my 4L80E, but there are others out there from TCI and PCS.

[gostranger]

i am doing this right now i bought an aftermarket harness and it was part of the engine harness as the stock one is it should not be a problem

[63 & 64 Bowties]

Originally Posted by vin63

Sometimes it's easier to get a stand-alone transmission harness/control module that way you can just focus on the correct ECM for the engine type you end up getting. I'm running a CompuShift unit with my 4L80E, but there are others out there from TCI and PCS.

How does the trans know when to shift? I've heard that stand-alone harnesses only work for manual shifting and they have no brake function. Is that true with yours?

[Clyde65]

With the stand alone trans controller, it has a little brain that I think you can adjust. With the stand alone harness the PCM does all the thinking after it is programed....Not sure if this is what you asking tho.

[vin63]

Originally Posted by 63 & 64 Bowties

How does the trans know when to shift? I've heard that stand-alone harnesses only work for manual shifting and they have no brake function. Is that true with yours?

The stand-alone controllers operate in the same way as the OE controller - the main harness from the trans, speed sensors, etc, and a throttle position sensor. These aftermarket controllers also allow the user full automatic function to manual shift even with paddle shifters, etc. The TCI and PSC units can be tuned with a PC-based computer (laptop) for a myriad of variables, including shift firmness, etc. The CompuShift that I have has a few user selectable standard programs (for lack of a better term) that address the most common user types. Here are a couple of links...

http://www.hgmelectronics.com/products/compushift

http://www.powertraincontrolsolutions.com/

[cl08]

Originally Posted by gostranger

i am doing this right now i bought an aftermarket harness and it was part of the engine harness as the stock one is it should not be a problem

What brand of harness are you using? Are you using an aftermarket PCM or stock?

[gostranger]

i bought mine from a company called Techrods and paid 456.95 shipped to the door i think i remember buying it through ebay because it was like 100 bux cheaper that way rather than going to there website i did a tone of searching and this was the best buy at the time hope this helps