Fixing a 2nd gen 3sgte harness / preping for my swap, no, its not going in Jenns car, its going in MINE! ;) Options

[lagos]

yup, mikes original diagrams back in the day had a few mistakes in them..hehe

There were actually a few revisions of them. The one DG got was a really bad one with a lot of mistakes, while the later ones were mostly correct with maybe 1 or 2 small mistakes, but I dont think he ever got those.

This post has been edited by lagos: Dec 28, 2008 - 5:38 PM

[presure2]

yup, mikes original diagrams back in the day had a few mistakes in them..hehe

There were actually a few revisions of them. The one DG got was a really bad one with a lot of mistakes, while the later ones were mostly correct with maybe 1 or 2 small mistakes, but I dont think he ever got those.

yea..i have all that stuff too

[presure2]

so since we're going over all this stuff, i figured i'd might as well post some pics of the ecu and interior plugs, so you guys that are following along would know what we're talking about, so here they are.

first the 3 ecu plugs. just a note here, the plug labled E8A is the plug that goes from the ecu to the interior of the 5th gen. when you swap, you need this plug to complete the harness conversion. IIRC tweak can get this plug new, but you can also get them from a junkyard.
so on to the pics.

E8A:


E6B


E7C


and the interior plugs from the 6th gen that get wired in, and the circiut opening relay(COR)

II1


II2


IJ1


and the COR

[playr158]

very nice work my friend.
I dig the attention to detail, the amount of knowledge you are providing and finding 1 more way to save weight.

[presure2]

and finding 1 more way to save weight.

i knew you'd dig that!

[lagos]

Nice!
I'll try to post up some pics of the 5th gen plugs that need to be converted for the fuse box wiring, as soon as I get some batteries for my camera.

[CelicaST_CALI]

Another swap..-_-...rabbits i tell you...



Some great info in here!!Cant wait for an engine pic (hint hint)

This post has been edited by CelicaST_CALI: Dec 29, 2008 - 8:38 PM

[presure2]

so i took the harness out to the garage for a quick test fit, and woot, it does. quite well in fact.
batteries were dead when i went out, so the next time i bring it out ill snap a few.

[lagos]

so i was looking at my harness here, and correct me if Im wrong, but it seems like you have two ways of flipping the harness.

1. flip it all the way down around where the injectors are. This will give you the cleanest flip, but you will have to shorten a lot of the harness because it will be too long at this point.
2. flip it somewhere before the injectors. However with this method, you will have to bend the harness in half and possibly create a bulge from bending all that wire.

or am i missing something here?

[presure2]

so i was looking at my harness here, and correct me if Im wrong, but it seems like you have two ways of flipping the harness.

1. flip it all the way down around where the injectors are. This will give you the cleanest flip, but you will have to shorten a lot of the harness because it will be too long at this point.
2. flip it somewhere before the injectors. However with this method, you will have to bend the harness in half and possibly create a bulge from bending all that wire.

or am i missing something here?

art, once you unloom the jdm harness from the boot, past the injectors, you pull everything but the coil, ignitor, map, diagonostics box, afm, waterneck, reverselight switch, tps, and speed sensor twoards the USDM passanger side of the harness. you may or may not have to cut and splice a few wires along the way to get it to come apart, and then you will have to legthen all the wires for all the stuff i listed above except the TPS and speed sensor.
then on the other side of the injectors, you will have a load of extra wire, you cut that out, resplice it together (it should be alot less than i had to do if its not already extended) and your good to go.

i cant see flipping it before the injectors, kinda defeats the purpose.

[lagos]

Right, so I will have to shorten the harness then.

[presure2]

Right, so I will have to shorten the harness then.

some of it, yes.

[Defgeph]

Nice work dude

[hurley97]

Nice work dude

What's this guy doing here? I thought he was banned or something...

[lagos]

I noticed a potentially horrible mistake that a n00b could make when wiring the harness...

Manny, in your fuse box, from the EFI relay you should see 2 black wires with yellow stripe. Are both of those wires soldered into a Y into another black wire with yellow stripe or is just one of them connected and the other one left hanging?

I'll have to double check to see how my harness was done, but those 2 wires really MUST be connected into a Y. That wire sends out power to all kinds of EFI related functions, but on our 6th gen fuse box those wires are very thin gauge compared to the wire they get connected to in the 3sgte harness. If someone was to make the mistake of connecting only one of them, they could end up sending power to the fuel pump, COR, tvis, etc... through one skinny 16 gauge wire! With our upgraded fuel pumps, you could end up with serious voltage drop! Connecting the 2 wires into a Y at least beefs up the wiring before it gets connected to the thicker 3sgte harness wire.

This is also a great reason why us swappers especially should rewire our fuel pumps to run new fused wire directly from the battery along with its own relay as was recently posted on mr2oc.

[95st-celica]

very nice.your the man..solder that bitch up! lol

[lagos]

Here are the two wires in question...

Top two are the very thin gauge efi wires from the 6th gen fuse box.
Bottom right is the 3sgte efi wire, and bottom left (red) is a 12gauge wire for comparison.
Notice how thin the 6th gen wires are. If someone connected just one of them, as the wiring diagrams say to do, you could end up with some large voltage drop issues.


However if you twist the two 6th gen wires together, they actually match the gauge of the 3sgte efi wire.



And here they are soldered and heat shrunk.

[playr158]

great job Art

even the small things matter

[presure2]

I noticed a potentially horrible mistake that a n00b could make when wiring the harness...

Manny, in your fuse box, from the EFI relay you should see 2 black wires with yellow stripe. Are both of those wires soldered into a Y into another black wire with yellow stripe or is just one of them connected and the other one left hanging?

I'll have to double check to see how my harness was done, but those 2 wires really MUST be connected into a Y. That wire sends out power to all kinds of EFI related functions, but on our 6th gen fuse box those wires are very thin gauge compared to the wire they get connected to in the 3sgte harness. If someone was to make the mistake of connecting only one of them, they could end up sending power to the fuel pump, COR, tvis, etc... through one skinny 16 gauge wire! With our upgraded fuel pumps, you could end up with serious voltage drop! Connecting the 2 wires into a Y at least beefs up the wiring before it gets connected to the thicker 3sgte harness wire.

This is also a great reason why us swappers especially should rewire our fuel pumps to run new fused wire directly from the battery along with its own relay as was recently posted on mr2oc.

nice catch art.
when i swap, i was planning on running new wire back to the pump anyway, what im thinking is to use one of the empty fuse blocks in the fuse box, and run it back to its own relay ect.
although, in my harness, the only thing that the EFI relay goes to is the COR, ecu, and fuel pump.
the way dave wired up the starter relay is really funky, it dont use the switch at all, its all wired in thru the coil side of the relay. he left the ST starter wire connected to the starter relay, but didnt wire in the 3sgte starter switch plug to it.
ill have to get a pic and MS paint it to show ya what i mean, its really odd.
i keep saying it the more and more i play with the harness. its amazing this car even ran, the way this harness is wired.
ohh and somthing you need to know.
if dave exended your harness, art, its missing the shielding around the distributor, injector wires, knock sensor, and o2.
the sheilding was just cut away from the corresponding wires, and he just extended the wireing with all the other wires in the harness.

and we wonder why these 2nd gen swaps seem to run great at times, and like ass at others..

[presure2]

so here is a pic of what im talking about:



so, im planning on just wiring the 3s starter switch wire into that ST wire, like it should be.