Cheap ebay ls swap harnesses? What's the deal?

Ive been seeing manual trans ls harnesses on ebay for ~$100 with all new connectors and a fuse panel. For that price, i almost can't justify stripping down the 3 used harnesses i have here to make a mint harness. 

Is it too good to be true? Known issues? Absolute crap?

In short, whats the deal?

I used one just recently and the tach wire was on the wrong pin and the length was wrong for how I wanted to lay it out but it came with an extra few feet of harness that I just cut off and repinned to the ecm plug. (super easy). Was nice having new connectors for everything. I imagine it's all cheap though so no idea on longevity. It's been on the car for a year and about 5k miles so far.

Limited experience with the LS ones but the Honda ones are surprisingly ok, probably want to go through and look for pin errors and stuff that I'll admit I don't do with a RyWire harness 

I wonder how much of one id be able to use for the LS4.9

There's a couple for $75 that are 4l60 style. Other than the extra trans connection, any reason it wouldn't work for a manual trans swap?

Also, doing more digging it seems that the biggest issues are in quality control. Looks like double checking against the factory wiring diagram before install is mandatory with these.....

Chinese wiring sweatshop with next door sweatshop pumping out connectors.

The one guy in the LS Ranger swap group posted a photo once and it was clearly a Chinese factory with a wire harness board.

Byrneon27 said:

Limited experience with the LS ones but the Honda ones are surprisingly ok, probably want to go through and look for pin errors and stuff that I'll admit I don't do with a RyWire harness 

Even with RyWire I've had to fix some issues the wrong connectors and crimped wires upon arrival. 

From having designed a more experience LS swap harness, here are corners I would worry may have been cut. I do not have any experience with these low buck harnesses, but here is what I would check for if I had one.

• First, they probably used cheap labor even by the standards of countries where labor is cheap. Keep an eye out for just general careless work.
• There's a pretty noticeable difference between a connector from Aptiv or Sumitomo and a place like III-B. Bottom of the barrel connectors are a lot worse in terms of how well they hold together and resist corrosion. There are also Chinese companies that  are midway between top shelf and junk in terms of quality and price.
• What wire did they use? Thicker wire and temperature resistance add cost. Same goes for wire loom; the cheap stuff will crumble in a year or so. 
• Was it put through a final continuity check for all the pins? There are automated systems that do this very quickly, but if they're trying to save every dollar, they may skip this step.

Buy one. They aren't that bad. Read pages 4 and then 5 of my build thread. Watch the YouTube video I linked for guidance on checking/fixing your harness. 
 

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/the-earl-truck-an-even-sloppier-ls-swapped-colorado/182097/page4/

Good starting point here Michael if you want to trim some fat off the stock harness.

Yep, they can be pretty good.  I bought one for the BMW swap I did (Gen IV LS/6l90)--it was great, but I might have had to flip a wire or two for the drive by wire gas pedal (you might even have to do this with a factory harness).  Just don't buy the absolute cheapest one you see.

On a side note, the eBay harness was considerably better than the one I got from Holley with the Terminator X . . .

If you need to go through them and verify all of the terminals are correct, and wire lengths are correct...  it seems easier to start with a used loom.

Pete. (l33t FS) said:

If you need to go through them and verify all of the terminals are correct, and wire lengths are correct...  it seems easier to start with a used loom.

Im going to have to look into making a standalone harness next. You're not entirely wrong. 

This is a cost/time decision. My time is much scarcer than it used to be. 

Thanks everyone. 

In reply to Dusterbd13-michael :

That is the beauty of it.  The harnesses largely ARE stand alone.  If you grab the underhood fuse box from whatever the harness came from, your life gets immensely easier, too.  You give the fuse box a half dozen inputs and the fuse box does all the relaying and fusing and what have you. (Battery power, ground, switched ignition, start signal, and some gauge related wires. CAN so the data link connector works. Fuel pump out.  Fuel level sender in, if you are using GM gauges.  That sort of thing)

As opposed to, say, a Subaru, where the engine harness is incorporated with the chassis harness and comes through the firewall in like three places to do it.

The other reason to use the fuse box is GM made all battery feed wires one color and all ignition feed wires another, no matter what circuit they are on.  Wrist thick bundle of pink and orange wires in the harness.  THAT sucks to sort out. 

Another thing on the used OEM harness, the wire quality is a known entity.  You never know what you are getting from a chinese ebay harness.  It could be copper strands or garbage pvc coated copper clad aluminum wiring.