What to do for 5.3L harness and ecu
 

Hi folks, I've got a 5.3L engine with a cut up harness and no ecm and im looking for advice on which route to go for getting a harness. It's got a cable throttle body on it and I plan to put a 4L60E or 65E when it's time to do the swap. I've found a harness and ECM from Painless but it costs $1,100, surely there's a cheaper alternative. Just looking to see what's out there, I want to rebuild the 5.3 and trans before installing so I'm kind of turned off on the idea of getting aided harness from a yard unless you guys think it'd be fine. Any help/advice is greatly appreciated!
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Re: What to do for 5.3L harness and ecu
 

You can find an ECM on ebay or in a junkyard, as long as its a v8/auto donor, and is ROUGHLY the same year as the engine (makes a bigger difference with dbw). Your tuner should be able to set it up to work with your engine just fine, and the 4l60e should already be the trans its setup for since 80% if 5.3 vehicles came with em.

I bought a complete harness, with its own relay box and fuse box, of very nice quality setup for my swap, for about $600. The used ecm should be like $65, and tuning can be anywhere from $150 (removing vats and setting up the year/engine combo) to 400 (dyno tune, tuning for cam etc)

Re: What to do for 5.3L harness and ecu
 

Unfortunately the previous owner only knew a year estimate of the motor to be a 99-03. Is that enough info to get a harness/ecu with? I really want to install a set of Texas Speed's Stage 2.5 5.3L heads, probably a 224/224 cam, and perhaps a ls6 intake so would the 60E trans hold up with a rebuild/shift kit? (I highly doubt I'll ever take it to a track)

Where'd you get the worked harness from? That sounds like a good deal to me!
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Re: What to do for 5.3L harness and ecu
 

Check out this link:

http://psiconversion.com/index.html

Re: What to do for 5.3L harness and ecu
 

My harness was from fuelinjectionconnection
I think that SHOULD be enough info, since your running a cable throttle body (or the car-tb if you switch to the ls6 intake) you don't need to bother with the DBW problems.

Put up pictures of the engine...is the fuel rail plastic or metal, does it have 2 inlets?


Most likely if you can find a 00-03 computer from a v8/automatic truck, it should work....BUT DO NOT buy one until we can see some pics and try to verify the year range on the engine. I hate wasting money.

Re: What to do for 5.3L harness and ecu
 

Thanks guys, I'll get some pics posted in the next couple days
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Re: What to do for 5.3L harness and ecu
 

If I remember correctly the 99-02 LM7 is different from the 03. I have both harnesses and they are different. I think the major difference is the dbw and the injector plugs (square vs. oval).

Re: What to do for 5.3L harness and ecu
 

Sorry everyone for not posting the pics. Work's kept me busy as today was my first day off since 9-1. Tomorrow I should have enough time to snap some pics between running a 5k, nephew's football game, and going to the state fair... Lol, so this weekend I'll have them up
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Re: What to do for 5.3L harness and ecu
 

Here you go guys, driver's side has the two tubes going towards the rear of the motor.
http://i20.photobucket.com/albums/b2...e71_05/037.jpg

Passenger side has the one tube that is plugged is going to the front of the motor, not sure if a line goes to it so I took a pic.
http://i20.photobucket.com/albums/b2...e71_05/040.jpg

And the TB
http://i20.photobucket.com/albums/b2...e71_05/044.jpg
http://i20.photobucket.com/albums/b2...e71_05/045.jpg

Re: What to do for 5.3L harness and ecu
 

come up to oklahoma city and i'll just give you my complete harness and ecu....

Re: What to do for 5.3L harness and ecu
 

I'll be in town for the Notre Dame game next month lol
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Re: What to do for 5.3L harness and ecu
 

wish i can find tickets for less than $300 each..... Let me know, and i can meet on the s.side of norman...