This is a basic list of connectors common to 3rd gens, LTx and LSx swaps. All PNs are from mouser. LSx defaults to GEN III unless otherwise noted. The list will be updated as PNs are found and other necessary connectors identified

http://www.mouser.com/

Throttle position sensor (TPS)
Early style on the left, later style on the right. All TPIs, 88-89 TBI and 85-89 V6's use the early connector. 90-92 TBI/V6, vortec trucks, LTx and LSx's used the later style

Body PN 829-12110192
Terminal PN

Idle Air Control Stepper Motor (IAC)
Early vs late again, same year interchanges

Body PN 829-12162188
Terminal PN 829-12089290

Manifold Absolute Pressure sensor (MAP)
Early Vs late again, all 3rd gens and LTx engines used the early style. LSx uses the later

Body PN 829-12129946
Terminal PN 829-12084200

Idle Air Temperature sensor (IAT)
3 wire LTx/LSx MAF/LSx crank/LSx cam sensor
Truck 5 wire MAF
Separate IAT is used on 3 wire MAF installs. 5 wire MAFs have a built in IAT. The LSx crank and cam sensor connectors use the same body and terminals, only wire color changes

IAT Body 829-12162197 Terminals 829-12089290
3 wire body 829-12059595 Terminals 829-12084200
5 wire body 829-15305555 Terminals 829-12191819

Injectors
TPI injectors sometimes have a long rubber boot covering the exposed 4-5" of wire. All later styles are simply wrapped in tape
Car style injectors interchange freely between V6, TPI, LTx, LSx. Truck injectors are specific to trucks and GEN IV LSx engines

Car body 829-12129142 Terminals 829-12077939
Truck body Terminals

Knock sensors
Blue is knock, green is thermal temp switch for 3rd gen automatic fans. Connector bodies can be black or white. LSx engines use an inline connector attached to a separate knock sensor harness that is completely different


Oil Pressure sending switch and fuel pump bypass
Left is early 3rd gen, middle later 3rd gen, right LTx/LSx single wire senders
3 wire late style connectors fit 1 or 3 pin senders, but 1 wire connectors only fit 1 wire senders. Not a problem unless you're reusing a 3rd gen sender on the new engine

Body 829-12065401

Heated Oxygen Sensor (HO2)
There are numerous versions of the HO2 connector varying between vehicles. These are the two most common
Left LTx/vortec truck/S10/early LSx truck right Fbody LS1

Square body 829-12160482 Terminals 829-12077628

Vehicle Speed Sensor (VSS)
3 styles, 82-89 3rd gen, 90-93 3rd/4th, 94+. LTx engines used the previous YEL/PPL colors while LSx engines use Lt GRN/BLK and PPL/WHT. The connector body didnt change from LTx to LSx

LTx/LSx body 829-12162194 Terminals 829-12089290

 

LSx Coil connectors
Hardest connector to find in a junkyard for those piecing a harness together

Body 829-12047938

Alternator
Early 3rd gen, later 3rd gen, LTx, LSx. Colors varied depending on the year. LSx alts used 1 wire for Fbody, 2 for early truck, 3 for Vette and GEN IV trucks

LSx body 829-12186568 Terminals 829-12048074

Coolant Temp Sensor (CTS)
PCM sensor, not for the gauge. 3 wire connector on the right is actually the Fbody AC high pressure sensor. Since most swaps dont reuse AC, this is often recycled for the 98 Fbody temp sender which combines the CTS and gauge sender into one sensor

2 wire body 829-12162194 Terminals 829-12089290
3 wire body 829-12110192 Terminals

C207/C221
3rd gen under dash connectors, these contain most of the fuse wires and a few gauge functions like MIL and speedo
Left is dash side C207, notice its two connectors. Middle C221 (if equipped), right engine side C207


C100
3rd gen main bulkhead. Absolutely essential to the swap. The car wont run without this or a similar replacement
Engine side left, dash side right(reference)


Relays
Two most common types of relay for 3rd gens. If simply replacing a socket, I suggest using the later oval style as the inline style from early years was VERY prone to wire damage and shorts
Oval bodies were introduced in the mid 80's, but not used exclusively until 91. LTx/LSx stock relays were built into the fuse blocks

Oval body 829-12052287 Terminals 829-12052455

Transmissions
Left 700R4/4L60 right 4L60E/4L80E


LSx PCM connectors with covers
Left is stock LSx, right is from a later FWD 3.8. I prefer the FWD pieces because they look better and the covers are easy to pop off. Stock LSx covers are very prone to breaking


Heating Ventilation Air Conditioning
3rd gen HVAC connector. This houses the blower motor power, ground and AC request wire. Early 3rd gens had an external power wire

Body 829-12034295

 

subscribed!

gotta make sure to keep these handy for later

 

Howly cow!! This is a huge help for me. Thanks so much Pocket

 

I knew there are two different size contacts in the relay and connector so I did a quick lookup in the an old 1998-1999 Delphi catalog that I have had since that era. For the 630 series connector it lists three female terminals for three different cable ranges. 12052456(5.0-3.0), 12052455(2.0-1.0), and 12052457(0.80-0.50). I'm gonna order all three sizes so I won't be missing any.

HTH, Mike

 

This is why I despise the inline relays. All 3 of these connectors are junk

Fuel, Fan, AC respectively

 

I am doing a94 Lt1 swap and was trying to use the 86 camaro fuel pump relay A goes to fuel pump B- black is ground C- Ignition D- was to ALCL now to A7 spliced PCM FP relay control E- hot at all time on a Continuity test by probe B- and C it show a closed circuit is the relay junk and could use a four wire relay cause a wire going to A7 fuel pump relay control thank for your help

 

If I use the oval fuel pump relay is it a five wire? are a four wire? would I need a five wire one going to A7 red Pcm FP relay control ?

 

wow, very awesome tech post. very helpful

quick question.. anyone know where/how to buy some of these connectors/wires... most specifically. i need the wire and conector for the knock sensor (black plastic for my 1987 camaro). the one i have on there is melted and does not stay on, i have to press it on, then it just rattles loose a few mins later. is there a site that sells these? or gotta go through a gm dealership? also .. is the best way to redo it to just cut the old wire and splice the nw one on there..solder it etc

 

try e bay there were two guys there that were selling the connectors

 

Most relay sockets will be 4 wires. Fuel pumps have a prime connector to test the pump's function so a 5 wire is added. You can use a 4 wire socket for the pump relay still, you just wont have the test lead (never gets used anyways)

I find almost all of my connectors in local JYs. GM used nearly all of the same connectors for all vehicles. Check ebay if you're looking for new stuff. Ill send you a PM because Ive got like 30 of them

Generally, yes the replacement connectors are cut and spliced on. Some of the new connectors use push-to-seat terminals and can be depinned with a paperclip instead of cutting the wires. This is helpful when replacing a broken tab

 

If you know what series the connector is you can seach sor the series on Mouser and find a lot of the connectors GM uses. You can even go on Mouser and just search for connectors. I started going through them on day while I wa sbored at work. It is nice because it will even cross the proper pin connectors and mating connector for you so you can get everything you may need for them. It is amazing how cheap most of them are too, if you are willing to take a little time and look for them.

 

This is why I'm happy to have a 1991 Body side harness... I think... Its still somewhat of a mystery what was in this car before I got it. I know it had a T56, and that they got the body panels from a Z28 and put it on the RS including Z28 tags and 5.7L Tuned Port Injection label on the back, but I'm still looking to see what harness I've got. I really need to get out to my in-laws and pull my wire harness (only connected by the bulkheads now) and start re-working it for the LSX swap.

 

My fuel pump relay connector looks just as bad. So, I picked up a fuse box w/ relays from a '94-'95 LT1 Caprice. I also grabbed some good oval style relays.

 

Is there a place to get a replacement version of this? Or something similar? I doubt I can tear out the factory rubber/whatever is on the enginebay side without destroying the body. I'd like to clean up my harness and run some more wires through this bulkhead.

 

why do that if your c100 is good if you need to other wires other places in firewall to run em through

 

https://www.thirdgen.org/forums/elec...ctor-info.html
https://www.thirdgen.org/forums/elec...ector-oem.html

 

As always, Pocket amazes. Thanks man.

 

hey i got some questions i hope maybe u can help me out ....i have a 1986 trans-am it originally came with a 305 tpi i sold the motor and ecm im in the process of selling my stock wiring harness and yeah i know its dumb but i need the cash and that cash is going to help me get a 1988 corvette 350 motor with aluminum heads it will come with ecm and wiring harness my question is will that harness from the corvette on the bulk head side is it similar to the bulk head on the original harness if not will it fit on the same spot i know ima have to splice sum wire in it to make it longer or shorter to fit the stock location on my car so if u can help out with this please help

 

Simplest job is to sell the corvette harness and buy one from a Fbody matching your year

 

thats true how much u think i can get for corvette harness

 

Check on ebay. Id wager enough to source a Fbody one

 

ill check and thanks u just made trouble shooting a lot easier

 

i now have another problem but nobody helps me out i have the 1989 350 tpi in the car and i nought a 1989 harness and ecm to match the engine but they told me about hooking up the harness to the bulkhead and would need to repin some wires i looked up into it and confused about repining i forgot to mention this is on a 1986 trans-am it originaly had a 305 tpi i sold the 305 tpi with origal harness and ecm

 

89 harness in an 86 will require a repin of the body connectors. This is not the thread for that, repost in the electronics, engine swap or TPI forum. Under the LS1 swap sticky, post #4 there is a link to additional swap info. All year body connectors are listed in there strait from Alldata

This thread is to ID and source replacements for various connectors found on common engines in 3rd gens and swaps

 

im sorry about posting this here its just i put some of those postings on the tpi and electronic section but i get no help from anyone but sorry well thanks for the help ill look it up

 

I also posted else where and nothing found.
I am looking for the source for the dist connector to the Ign. Module.
Looks like this

Can any one help me on this?

 

http://www.mouser.com/Interconnects/...ors/_/N-1ehb5/

Might be easier to ID the terminal it uses then sort by connectors that use it

Good luck

 

Subscribed

 

Pocket, not sure if I follow you.
If you are asking this,
It Connects to the back side of this Module.
It is the connector for the Dist. Pick Up Assembly

When going into Mouser and putting in 1 row, 2 positions. I don't see it. I tried that before i posted the first time

 

the later style connectors, are those for ls engines?

 

I looked for it and didnt see anything, but the filter often cuts out the correct part because its classified wrong. Thats why I suggested searching by terminal type

Yes the later style connectors are for LSx engines, but alot interchange freely with older stuff like LT1s and TPIs. Example being, the IAT connector hasnt changed since EFI was started

 

pocket, on truck intakes, what is the sensor that goes on the very top/ back of the intake???

 

MAP

 

I don't fully understand how to wire up the c100 or any of the other stuff what do I need to strip on the factory v6 harness and on the 5.3 harness like for alt on the factory do I need to cut connect off and soder the alt wire off the 5.3 harness on it?

 

Check out the lsx swap sticky, pocket has a few wiring threads in the sticky. One of them specifically deals with stripping a 3rd gen harness.

 

LS1 red connector drivers side near front injectors? I believe its canister purge can anyone confirm?

 

Red two wire connector where you are describing is the purge solenoid plug.

 

I'm a little confused on this sensor. I understand that the original LS harness had two wires, but your saying theirs a three wire version that one wire could be used to run to the oem e temperature gauge? What sensor do you use? The original one is only a two pin type sensor?

 

yes use the 3 wire sensor. Two to the pcm and the third to the dash. get a sensor for a 1998 Camaro Z28, it is the three wire type

 

Thanks for the clarification, I think I'll go that route instead of using the original gauge sender.

I just need to get a part number for the connector. Someone on eBay has them.

Is the F Body AC harness that gets used actually part of the LS 1 engine harness?

 

yes you can use the ac pressure sensor pigtail if you are not using it for ac on your car, it is the same connector needed for the 3 wire sensor. Or hawksthirdgenparts.com sells the sensor and wire, here is the link.
http://www.hawksthirdgenparts.com/pr...onversion.html

 

Did anyone ever find a replacement C221 connector? Im in need of the engine side connector to finish off my LT1 swap.

 

try a bone yard

 

been there, problem im having is only a handful of models got the C221 connector. IIRC 86-88 Irocs and maybe V6's. But its in the connector that STOCK inj fuses, back up lights, and fan fuses connect to.

Worst case i have to depin it and either splice a different connector in, or add them to some of what I wont use in the C207. I was just hoping that I could connect everything as is.

 

Move them over to the C207

 

Yup, thats what im going to do. I found the connector PN btw, its 12101900, or AC Delco PT171, which can be found on Amazon for about 28 bucks or Rock Auto for more.....

 

pin outs for a 4 wire hvac connector?

https://www.thirdgen.org/forums/elec...-pin-outs.html

 

12ga red 12v battery
12ga blk fan grd
18ga lt blu Ac request
18ga dk grn/wht fan override (not used for swap)

Earlier years are similar, with the 12v wire divorced to another single pin connector

 

Ac request (lt blu) is 12+ from control (head) unit correct?