89 yj wiring help

miami30141 · 05-01-2010, 09:45 PM

I am needing the wiring schematic for a 89 yj islander if anyone can help I am trying to wire up a 97 tj 4.0 to replace the 4.2 any help would be greatly appreciated.thanks Richard

demesauce · 05-01-2010, 11:14 PM

I recently replaced my 4.2 for a 4.0 in my 88 YJ. I hope you grabbed the entire wiring harness off the donor vehicle. Go to a junk yard and take pics of a vehicle with a 4.0. Trace all the wires and then go back home and try to compare the two vehicles. You probably won't be using all the wiring, such as A/C. But it's a good start.

**dodger889** · 05-01-2010, 11:35 PM

Are you using the 97 wiring or doing something else??

**Douglas S.** · 05-02-2010, 01:29 AM

That '97 is OBDII, which is not going to be fun to wire.

**Que89YJ** · 05-02-2010, 04:24 PM

It can be done but a x2 on what you are going to deal with. If you are serious about it then I strongly suggest you get the wiring diagrams for both. Make sure you get the flywheel and the trans as well as all the under hood wiring(including the fuse block)if possible. They TJ had a different speedo hookup and the crank sensor pattern from the fly wheel is extremely important.

green89yj · 05-02-2010, 04:29 PM

Ok. I just put a 96 XJ 4.0 into my 89 YJ and I ended up grabbing all the wiring, from the tail lights to the headlights and everything in between because it made it much easier for me.
I have pretty much gutted the YJ and am using all the turn signal and ignition switch, etc from the XJ. On the tail lights you will probably have to wire in a tail light converter ( like you plug trailer lights into) or run a separate rear turn signal.
There are plenty of threads out there about 4.0 swaps if you do a little searching.

miami30141 · 05-04-2010, 07:01 AM

I got the 97 tj motor, engine harness and computer plus the PDC or power distribution block and I plan on not using the obdII just splicing the yj harness to the tj harness where needed thanks for the help.Richard

**rustywrangler** · 05-04-2010, 07:03 AM

Quote:

Originally Posted by miami30141

I got the 97 tj motor, engine harness and computer plus the PDC or power distribution block and I plan on not using the obdII just splicing the yj harness to the tj harness where needed thanks for the help.Richard

You can't not use the OBDII. Everything you just listed is part of it. And the YJ's wiring will not control a fuel injected rig.

Old4X · 05-04-2010, 07:10 AM

Jeep Wrangler YJ Wiring Diagram

miami30141 · 05-04-2010, 02:28 PM

I meant I am not wanting to have the obdII port I know it will make everything easy to diagnose but I am not that good at wiring and I have gotten some high quotes on wiring this thing up like 30hrs at $60+ an hour.

miami30141 · 05-04-2010, 02:37 PM

Thanks for the help Old4x

miami30141 · 05-04-2010, 02:40 PM

So is it really that hard to wire up I have read it only takes 11 or 12 wires to make the jeep fire up but then I here it is a real pain in the A-- to do I have had the engine in for over a 1 1/2 and have not wanted to screw something up with the 97 tj harness.

**dodger889** · 05-04-2010, 10:37 PM

Here is what you could do is wire it up for obd1 with a wiring harness from a 92-95 yj or xj that would simplify thing greatly. If I'm not to badly mistaken all the sensor for the ECM are the same. If I'm wrong someone will chime in here.

**Que89YJ** · 05-05-2010, 06:56 AM

I am going to say it again. It is doable but: The fuel tank needs to be swapped, the engine flywheel is needed, the trans has sensors on it that your current rig doesnt, and all the wiring under the hood including the fuse block need to be swapped. It is doable, it is a PITA, we had to "modify the YJ with TJ wiring to make test "mules" here. If you get the Service manuals for both years(believe me when I say you want the service manual and not Chiltons or any of the others) you can make it work. I still have to agree with Dodger that the OBDI in the XJ/YJ wiring harness will be much easier for you in the long run. You are still going to need that gas tank and fuel pump and if I remember right the 4.2L only had a single fuel line to the front too. Someone can correct me if I am wrong.(LOL and they usually do!)

**dodger889** · 05-05-2010, 09:54 AM

For the fuel system has a return to the tank on 89. If he has a plastic tank he can get just the fuel pump for a 4 cyl. will work. Just has to use high pressure fuel lines and clamps for the same. For all who read this yes there is a difference between the two standard hose clamps and high pressure hose clamps.