Building Injection Harness

Friday

Hero Member
Joined
Apr 7, 2007
Messages
266
Likes
1
Points
18
Age
119
Location
Tecumseh, KS
#1
2000 Jeep Cherokee 4.0L AT. Engine compartment fire last year. Putting it back together. Rebuilding injector harness from scratch. Having trouble identifying some of the wires. Harness has 4 BR/YL wires. Schematic indicates they are all grounds: MAP, TPS, Intake Air Temp, Coolant Temp. MAP, IAT and Coolant Temp look to merge before going to PCM as single wire. TPS is separate single wire going to PCM. How do I tell which one goes to the TPS? Similar situation with injectors. I can match the driver wires just fine, but the supply wires has me baffled. They should be orange. I have three orange wires. I have a small section of the harness that survived the fire and in it are three orange wires merged into one. Looks like three #18 going into one #16. The schematic shows all 6 injectors with orange supply merged to one wire. which goes to the Power Dist Center to fuse #21 (20 Amp). The MAP and the TPS each have an orange supply wire. Can anyone help me sort this out?
 
Joined
Nov 14, 2006
Messages
4,919
Likes
53
Points
48
Age
119
#2
Did you price a harness - maybe getting the OEM part # then google...

I made this mistake recently - hhis is a CHEROKEE XJ not a GRAND cherokee WJ?


will send some diagrams later- OEM and others -
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
10,253
Likes
183
Points
63
Location
St-Hyacinthe, Quebec, Canada
#3
Here are powertrain diagrams for MAP, IAT, ECT, INJ 1-6, TPS.

ace 3 is for connector pins at pcm and related sensors and actuators.

E-bay engine harness for 2000 jeep sport cherokee. http://www.ebay.com/itm/99-01-Jeep-Cherokee-Sport-OEM-Factory-Complete-Engine-Bay-Harness-/191357989345?hash=item2c8dd331e1&vxp=mtr

This one for 40$ looks sketchy. http://www.ebay.com/itm/Jeep-Cherokee-Engine-Main-Wiring-Harness-connectors-wires-relay-fuse-box-/251689294666?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a99d9db4a&vxp=mtr

I notice there is a difference in calif wiring. If you don't live in calif be sure to check that out. Now seeing you are a packers fan, I highly doubt you live down in calif. ;)
 

Attachments

Friday

Hero Member
Joined
Apr 7, 2007
Messages
266
Likes
1
Points
18
Age
119
Location
Tecumseh, KS
#4
kev2 said:
Did you price a harness - maybe getting the OEM part # then google... I made this mistake recently - hhis is a CHEROKEE XJ not a GRAND cherokee WJ?
will send some diagrams later- OEM and others -
Kev: It's an XJ. No used harness in my area at any salvage yard. Found some on eBay, but not exactly what I want.
 

Friday

Hero Member
Joined
Apr 7, 2007
Messages
266
Likes
1
Points
18
Age
119
Location
Tecumseh, KS
#5
nickb2 said:
Here are powertrain diagrams for MAP, IAT, ECT, INJ 1-6, TPS. ace 3 is for connector pins at pcm and related sensors and actuators.
E-bay engine harness for 2000 jeep sport cherokee. http://www.ebay.com/itm/99-01-Jeep-Cherokee-Sport-OEM-Factory-Complete-Engine-Bay-Harness-/191357989345?hash=item2c8dd331e1&vxp=mtr

This one for 40$ looks sketchy. http://www.ebay.com/itm/Jeep-Cherokee-Engine-Main-Wiring-Harness-connectors-wires-relay-fuse-box-/251689294666?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a99d9db4a&vxp=mtr

I notice there is a difference in calif wiring. If you don't live in calif be sure to check that out. Now seeing you are a packers fan, I highly doubt you live down in calif. ;)
Nick:

Packers fan, but born and raised in Kansas. Still there. I was going to avoid buying a used harness, because I've discovered so many oddities in these Cherokees. The $40 dollar one is from a 1991, it will have the wrong injector connectors on it. The other one is just too much money right now. I have all the sensor connectors with 3-6 inches of wire. They survived the fire. The injector harness burned completely. If I can figure out the orange and brown/yellow wires, I can figure out the rest (I think). Thanks for the schematics.
 

Friday

Hero Member
Joined
Apr 7, 2007
Messages
266
Likes
1
Points
18
Age
119
Location
Tecumseh, KS
#7
Here are two pics. One of the injection harness wires I have to attach to. You can see there are three black wires soldered together into one, the rest are single wires. This makes 23 wires. If you count up the injectors and sensors, this is the correct number of wires. The other pic is of the survivor of the orignal harness, just a piece of it, but you can see the three orange soldered into one. You can also see a single DG/OR wire sticking straight up. Well, each injector is supposed to have a DG/OR for supply. But if this wire is supposed to be split into 6 wires, that makes the total number of wires 28, which is 5 too many. This is where I am confused.
 

Attachments

Friday

Hero Member
Joined
Apr 7, 2007
Messages
266
Likes
1
Points
18
Age
119
Location
Tecumseh, KS
#8
Re: Building Injection Harness Hey Nick!

Nick: Didn't you help me with a real mess on a 2003 Mitsubishi Lancer about 3 years ago? Started as an electrical problem, turned into a fuel pump problem, finally went to the bone yard? I was getting cluster headaches during the entire process and every night when I went over there to work on it, the smell of gasoline would trigger a headache. I was never so glad to see a car go to the bone yard than that one.
 
Joined
Nov 14, 2006
Messages
4,919
Likes
53
Points
48
Age
119
#9
I will try to add- seams nick can communicate these wiring diagrams well- me not so clearly...
you are replacing starting from a connector- tell me where the connector is - then I will get a pin out of that connector ie C107 and we can do the wiring from there... Also the splices...
 
Joined
Nov 14, 2006
Messages
4,919
Likes
53
Points
48
Age
119
#10
are you sure about fuse 21 -

I show the ASD when closed also splits to fuse 18 - this goes to ign coil and the 6 injectors
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
10,253
Likes
183
Points
63
Location
St-Hyacinthe, Quebec, Canada
#11
I would worry more about getting PCM side of injector sequence down right. One 18gauge wire from ASD relay dg/or supplies voltage to all, simple to extend that wire to cyl # 1 and splice it 5 times from cyl#6 on up finishing with #1 inj connector.

If it was me, I would go and buy a bunch of terminals to limit solder points. Some loomex also. Masking tape to tab identify each wire as you go along. Seems like the brunt of the fire got the intake side and not much more. So be relatively fast to get this done.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
10,253
Likes
183
Points
63
Location
St-Hyacinthe, Quebec, Canada
#12
TPS wire is not a single wire. It shares the same ground PCM pin #4 C1 as the others (ECT, IAT, MAP) and crank and cam sensors, also the fuel pump module. Splice S111 and S114. All wires br/yl are 20 wire gauge before splice S111. after they are 18gauge going to pcm pin#4 of C1.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
10,253
Likes
183
Points
63
Location
St-Hyacinthe, Quebec, Canada
#14
As for your orange wires, they are 5v supply from pcm to cam, crank and TPS and MAPand IAT. Pin #17 of C1 @pcm orange wire 18gauge. After splice S115, 20guage.

TPS signal wire is OR/DB 5v is OR pin #17 wire and ground/signal return BR/YL pin#4 for all these @ PCM!!
ECT signal wire is TN/BK
IAT signal wire is BK/RD
CKP signal wire is GY/BK
CMP signal wire is TN/YL