You need to check right at the Engine Computer. I have a real lot of Chrysler service manuals but the closest I can find for yours is for a 1993 Grand Cherokee, and that did not have the 2.5L engine. Chrysler was pretty consistent though with their wiring from year to year and with different engine sizes so let me see if this looks right.
They show terminal 3 as a pink/black wire with full battery voltage all the time for both the 4.0L and 5.2L engines. Terminal 9 is a light blue or a light blue/red wire that gets 12 volts from the ignition switch when it's in "run". You can remove the 60-pin connector and measure right on the terminals, but do not stick a meter probe in too far as that could stretch the terminals.
Next, there are multiple power ground wires to check. You can use an ohm meter to measure the continuity but a more accurate test is to remove the connector's rear cover, then back-probe the terminals through the rubber seal and measure voltage while the connector is plugged in and the ignition switch is on. Typically you can expect to find as much as 0.2 volts but more than that indicates a high-resistance connection. Terminals 5, 11, and 12 are all grounds and are all black/tan.
All of these wires are in one of the outer of the three rows of terminals, (assuming you have the common 60-pin connector, and not the newer style three smaller connectors). One row has terminals 1 - 20.
I should have you check something easier before I jump the gun and head to the computer. There is four terminals on the ASD relay socket. You already jumped the two high-current terminals. Look at the other two that are on the sides and parallel to each other. One of those should get 12 volts all the time the ignition switch is in "run". Make sure that is showing up.
Sunday, August 25th, 2013 AT 1:32 AM