Here I will concentrate on wiring OBD II computers that have distributors. This includes 97-99 TJ?s and 96-98 Grand Cherokees. You will need a PCM that does not have a security system. Most likely, you wont have the PDC so I will teach you how to wire relays individually. Because they changed the wire colors every year, I cannot give you wire color specifics. For the most part, the correct wires run through the same connectors and are in the same location on those connectors with a few exceptions. To do this correctly and accurately, you?ll want the electrical manual for the donor engine year available at the dealership. The most important diagrams, which are the pin out diagrams for the PCM, are available here:
97 TJ pin out diagram(excel)
98 ZJ pin out diagram(excel)
            To complete this swap in any kind of timely manner, you?ll need to get the ?engine harness? from the donor vehicle. This includes the white and black connectors of the PCM and the harness connected to these. Depending on donor, there may be about a dozen unplugged connectors on this harness, which may seem overwhelming. Don?t worry, only about a dozen wires needs to be hooked up for the engine to run. You won?t have the third, gray connector, so you need to obtain one from a salvage yard. I hacked one out of a similar year Grand Cherokee with about 6 inches of wire left for splicing. You?ll also need three relays and of course various colors and sizes of wire.

Identifying Key Plugs:

            There are three main plugs that you need to be concerned with: C131, C132 and C144. These may be numbered differently in the FSM between ZJ, TJ and XJ but look identical between the models. Identify each plug based on the following diagrams. If your donor was a 2wd model it will be lacking wires such as the "4wd switch."
            (Note, if your plugs do not match these descriptions, try to get the electrical manual from JEEP to identify the correct connectors (or ask to use theirs for a minute). While the same wires do the same things, they?re may be extra wires or fewer wires associated with different models)

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	C131: Wire 1, 6, 7 and 8 can be left unconnected. Wire 2 must be Fused at 15 Amps. Wire 4 must be run to terminal 87 on what will be your ASD relay Wire 5 must be fused at 20 Amps Wire 10 connects to the fuel level sensor on the fuel pump, which does not need to be connected unless stock gauges will be used (along with a stock fuel pump assembly).
	C132: Wires with an (*) next to them indicate that they can be ground. Wire 1 and 2 is ground. Wire 4 is ground to trick the computer into thinking the starter relay is hooked up the way it wants to be. Wire 6 is connected to wire 2 of connector C144. This allows the alternator to work properly by allowing the PCM to shut off the charging circuit so your battery doesn?t get fried.
	C144: Wire 1 and 5 can be left unconnected. Wire 2 must be connected to wire 6 of C132. Wire 3 must connected to C25 of C3 on the computer (that?s the 25th pin on the grey connector). Wire 4 is ground Wire 6 is connected to terminal 87 on the starter motor relay.

            The following are diagrams to aid you in wiring relays. Please note that I did not include splice indicators in these diagrams. I only included what you should be concerned with. This goes for wire gauges as well. I did not include wire colors because they vary from year to year. This is for OBD II engines only (as far as I know).

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Starter Motor relay: Note that the neutral safety switch (PN/PS) is located either on your transmission or on your shifter (aftermarket) It basically provides a ground when the gear is in either park or neutral	ASD relay: Note, It appears from these diagrams that the ASD relay only controls the coil, but it also gives power to the injectors, O2 sensors etc. via a splice that was not shown.

Fuel Pump Relay: Note that the fuel sender is also part of the fuel pump module but was left off of this diagram. This will be discussed later.

            At this point, the engine should run, but there are still details to be dealt with to complete your swap. Those Details are as follows:

Wiring Gauges:

Here I will only cover wiring donor gauges. If you choose to use aftermarket gauges, instructions will be provided from the manufacturer. I won?t even begin to speculate on what gauges you might already be using.

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	Gauge Cluster The ABS warning lamp driver comes from the antilock brake controller (if equipped). Disregard for most swaps. Right and left indicator lamps are simply splices into your turn signal switch that power the indicators (you may already have an ?indicator? wire from your old gauges).
	Fuel Sender When mixing and matching tanks and engine harnesses (example: ZJ harness and TJ pump module) keep in mind that the big black wire is Ground. The sensor ground is in the same ?row? as this wire. The battery temp sensor uses this same sensor ground. The other big wire is controlled by the fuel pump relay. The low fuel sense is in the same ?row? as this wire.
	VSS This diagram will help if your installing an electronic aftermarket speedometer. The sensor signal is route to the new speedometer. From there it is route back on its normal course to the PCM.
	Data Link Connector (DLC):         The DLC is very easy to hook up. Just match the following wires with the wires on the Pin-out diagrams. The ?Fused B(+)? is a 20 AMP fuse. Also, ?Ground? means to actually ground the wire. Don?t connect these grounds to the ?grounds? on the computer. If using the donor gauge cluster, simply splice into the CCD Bus wires and run one set to the Gauge cluster.

Emissions Control Systems: The following are reproduced diagrams from the FSM. I do not attempt to explain these systems in detail.